A=12C (1990AJ01)

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¹²C (1990AJ01)

(See Energy Level Diagrams for ¹²C)

GENERAL: See also (1985AJ01), 2 [Electromagnetic Transitions in A = 11-12] (in PDF or PS), 12.6 [Table of Energy Levels] (in PDF or PS) and 12.7 [The decay of some ¹²C levels] (in PDF or PS).

Shell model: (1984CA1N, 1984ZW1A, 1985AN16, 1985AR07, 1985CA23, 1985KO2B, 1985MI23, 1986YO1F, 1987GU1C, 1987JI01, 1987KI1C, 1987PR01, 1987SC1J, 1988GU13, 1988JA13, 1988OR1C, 1988WO04, 1989KW1A).

Deformed Models: (1984LO05, 1984SA37, 1985RO1G, 1986KU1P, 1986LE16, 1987HO1C, 1987PR03, 1988KH07).

Cluster Model: (1983DZ1A, 1983JA09, 1984KR10, 1985DE05, 1985KO2B, 1985KW02, 1986GU1F, 1986KA51, 1986OR1C, 1986SA03, 1986SA1D, 1986SU12, 1986ZE1A, 1987JI01, 1987KU1B, 1987MI1L, 1987WA07, 1987ZE05, 1988FL1A, 1988HA39, 1988KA1Z, 1988MI26, 1988OS04, 1988OS1E, 1988RU1C, 1989KW1A, 1989OR05).

Special states: (1984BA38, 1984CA1N, 1984CO16, 1984CO21, 1984MO13, 1984SA31, 1984SA37, 1984TR1C, 1984ZW1A, 1985CA23, 1985CH27, 1985CO05, 1985GO1A, 1985HA1J, 1985KU22, 1985PA12, 1985RO1G, 1985SHZL, 1986AN10, 1986CH25, 1986DI04, 1986HU1E, 1986KA51, 1986KH1G, 1986OR1C, 1986PA06, 1986SA03, 1986SA32, 1986SU18, 1986VO07, 1987BL18, 1987BO1L, 1987CA1E, 1987JI01, 1987KA18, 1987KI1C, 1987MA08, 1987PR01, 1987PR03, 1987SC1J, 1988AJ1C, 1988AL1D, 1988BL10, 1988GU13, 1988KW02, 1988PO1C, 1988SP1A, 1989BA60, 1989KW1A, 1989OR02, 1989OR05, 1989RO03).

Electromagnetic transactions: (1984CI1B, 1984ER06, 1984LO05, 1984MO13, 1984VA06, 1985AR07, 1985CA23, 1985GR1A, 1986AN10, 1986CH25, 1986KE1P, 1986SA32, 1986VO07, 1987CA1E, 1987ER1F, 1987RA01, 1987ST1E, 1989BA60).

Giant resonances: (1984BA38, 1984RA1H, 1985GI1G, 1985GO1A, 1985OR1F, 1986ER1A, 1986NA1H, 1987FE05, 1987GOZK, 1987KI1C, 1987MI1L, 1988CO1G, 1988HO10, 1988MI26, 1989LH02).

Astrophysical questions: (1982BA1D, 1982BU1A, 1982CA1A, 1982GR1A, 1982WO1A, 1984CO1H, 1984HA1R, 1984LA1J, 1984LI1L, 1984RA1E, 1984TR1C, 1984WE1C, 1985AR1A, 1985BR1E, 1985DW1A, 1985GU1A, 1985HA1R, 1985HE1F, 1985KH1D, 1985KO2A, 1985MI1E, 1985NO1B, 1985TA1A, 1985YO1A, 1986CH1H, 1986CO1R, 1986DO1L, 1986GO1Q, 1986KH1G, 1986LA16, 1986LA1C, 1986MA1E, 1986MA2E, 1986SM1A, 1986SN1C, 1986SN1D, 1986TH1E, 1986TR1C, 1986WI1L, 1986WO1A, 1987AL1B, 1987AR1C, 1987AU1A, 1987BE1H, 1987BO1B, 1987BR1P, 1987CU1A, 1987DO1A, 1987DW1A, 1987FU04, 1987HA1C, 1987HA1U, 1987HA1E, 1987KR1M, 1987LA1C, 1987MA2C, 1987ME1B, 1987MU1B, 1987PI1E, 1987PR1A, 1987RA1D, 1987RI1B, 1987SA1D, 1987SO1F, 1987WA1L, 1987WA1F, 1988AP1A, 1988AR1H, 1988AS1D, 1988BA86, 1988CA26, 1988CO1D, 1988CR1A, 1988CUZX, 1988DE1I, 1988DU1G, 1988FE1A, 1988FO1E, 1988JU1C, 1988KA1G, 1988MI1A, 1988PA1H, 1988RE1F, 1988SC1A, 1988TR1H, 1989BO1M, 1989CU1F, 1989DE1J, 1989GU1Q, 1989HA1O, 1989JI1A, 1989KA1K, 1989ME1C, 1989NO1A, 1989TH1C, 1989WE1G, 1989WY1A).

Applications: (1984CA1D, 1984HO1E, 1986BR1Q, 1986DR1E, 1986EN1A, 1986FR1H, 1986HE1F, 1986KI1J, 1986KO2E, 1986KR1F, 1986PE1F, 1986ST1K, 1986WE1E, 1987NA1D, 1987ST1C, 1988AL1K, 1988BU1C, 1988GO1M, 1988ILZZ, 1988MA1I, 1988PU1A, 1988RO1L, 1988SC1C, 1989BO1L).

Complex reactions involving ¹²C: (1983AG1A, 1983AL1G, 1983AL1H, 1983BO1D, 1983EL1A, 1984AB1C, 1984AI1B, 1984AN1G, 1984BA2F, 1984CH1L, 1984DE1Q, 1984FI17, 1984GA1G, 1984HO23, 1984KA1J, 1984KA1L, 1984KO1P, 1984MA1P, 1984NA12, 1985PA08, 1984ST1B, 1984XI1B, 1985AB1F, 1985AG1A, 1985BA1V, 1985FA02, 1985GA1H, 1985GH1A, 1985GU1A, 1985HA1N, 1985JA18, 1985KA1E, 1985KA1G, 1985KAZQ, 1985KI1E, 1985KW03, 1985LI1B, 1985MC03, 1985MO02, 1985MO08, 1985NE1G, 1985PO11, 1985PO14, 1985SI15, 1985SI19, 1985ST1B, 1985TA18, 1985UT01, 1985WA22, 1986AB06, 1986AL25, 1986AV1A, 1986BA1E, 1986BA1Q, 1986BE2M, 1986BO1R, 1986BO1B, 1986BU1K, 1986CH2G, 1986CS1A, 1986GH1A, 1986GR1L, 1986GR08, 1986GR1A, 1986GR1B, 1986GU1F, 1986HA1B, 1986KI1C, 1986MA19, 1986ME06, 1986MO15, 1986PL02, 1986PO06, 1986RA1L, 1986RE13, 1986SA30, 1986SH25, 1986SH1F, 1986SO10, 1986ST13, 1986UT01, 1986VA10, 1986VA18, 1986VA23, 1986WA1H, 1986WE1C, 1987AK1A, 1987AN1C, 1987AR19, 1987BA02, 1987BA1I, 1987BA31, 1987BA38, 1987BA1T, 1987BE58, 1987BE55, 1987BO23, 1987BO1K, 1987BU07, 1987CH1L, 1987DE37, 1987DO13, 1987FA09, 1987FE1A, 1987GE1A, 1987GH1A, 1987GO17, 1987GR1O, 1987JA06, 1987KI05, 1987KO15, 1987KW02, 1987LY04, 1987MU03, 1987MU1D, 1987NA01, 1987PA01, 1987PA1D, 1987PO23, 1987RI03, 1987RO10, 1987SH23, 1987SI10, 1987SN01, 1987SO15, 1987ST01, 1987TAZU, 1987VI02, 1987VI14, 1987YA16, 1987YI1A, 1988AV03, 1988AY03, 1988BA28, 1988BO1O, 1988BR1N, 1988CA06, 1988CA27, 1988CE01, 1988DE1J, 1988EL1D, 1988FE1A, 1988GA11, 1988GA12, 1988GA31, 1988GH1A, 1988GO1F, 1988GO11, 1988GU1K, 1988HA03, 1988KH1B, 1988KH1H, 1988KHZX, 1988KI06, 1988KW1C, 1988LI1H, 1988MI28, 1988MO1K, 1988MU1E, 1988PAZS, 1988POZZ, 1988PO1F, 1988PR1C, 1988RE13, 1988RU01, 1988SA19, 1988SH03, 1988SH1H, 1988SI01, 1988SM07, 1988TE03, 1988TS03, 1988TS01, 1988UC01, 1988UT02, 1989BL1D, 1989BR35, 1989CEZZ, 1989CH28, 1989CI1C, 1989FI05, 1989GH1B, 1989GU1C, 1989HA43, 1989HA08, 1989PA06, 1989PO06, 1989SA10, 1989SE03, 1989SU05, 1989TU1A, 1989YO02).

Muon and neutrino capture and reactions: (1983GM1A, 1984KU20, 1984KU11, 1984MI11, 1984RU12, 1985AG1C, 1985AR1B, 1985BO1U, 1985GR1A, 1985KI01, 1985MAZZ, 1985PA05, 1985PA12, 1986DA1J, 1986DO06, 1986DU06, 1986FI1G, 1986KE1Q, 1986KU05, 1986LI13, 1986MA16, 1986PA06, 1987BR1L, 1987FU13, 1987HA1Q, 1987KO1P, 1987KR1L, 1987MI17, 1987SU06, 1987VA1P, 1988AL1O, 1988BO1X, 1988BR24, 1988DO05, 1988FU08, 1988MI11, 1988MI20, 1989AR1I, 1989DR1A, 1989GM1A, 1989KR1C, 1989MI1I, 1989NA01).

Pion capture and reactions (See also reactions 28 and 34): (1981HO14, 1983AB1B, 1983AB1C, 1983AG1B, 1983AK1A, 1983BU1D, 1983GM1A, 1983KO1M, 1983MA16, 1984AL1K, 1984AL1L, 1984AS05, 1984BA1L, 1984BA2L, 1984BA1M, 1984BE28, 1984BE1Q, 1984BE1R, 1984BO1L, 1984BO1H, 1984BU11, 1984CE1D, 1984CH26, 1984CO16, 1984CO1D, 1984ER06, 1984GE1A, 1984GI1D, 1984GM01, 1984GR27, 1984JI03, 1984KA31, 1984KO1P, 1984LE11, 1984LI03, 1984MA1T, 1984MA1G, 1984MA1U, 1984MI11, 1984OH04, 1984RI12, 1984RO1D, 1984SA1H, 1984SC1B, 1984TO1A, 1984ZI1B, 1985AB1E, 1985ALZX, 1985AM1B, 1985AR15, 1985AS02, 1985AZ1A, 1985AZ1B, 1985BA2F, 1985BA1V, 1985BE1C, 1985BI01, 1985BI04, 1985BU1G, 1985CO11, 1985CO16, 1985DI02, 1985FU06, 1985FU14, 1985GI05, 1985GR1E, 1985GU13, 1985KA22, 1985KO06, 1985KO2C, 1985LA20, 1985LE1E, 1985LI1E, 1985MA1G, 1985MA1K, 1985ME1M, 1985MI04, 1985MI1L, 1985MO1H, 1985MO1M, 1985OH09, 1985RI04, 1985RO17, 1985RO1M, 1985SA06, 1985SE21, 1985SM06, 1985TA17, 1985TA24, 1985TO15, 1985TO14, 1985VA17, 1986AB1J, 1986AG1C, 1986ALZL, 1986AN40, 1986AR1F, 1986AS1A, 1986BA3E, 1986BA81, 1986BA3H, 1986BE22, 1986BE2L, 1986BL05, 1986BO03, 1986BO1N, 1986CH39, 1986CH1Z, 1986CH1J, 1986CO1V, 1986CZ01, 1986DI07, 1986DU1M, 1986ER1A, 1986FA03, 1986FO03, 1986GA33, 1986GA14, 1986GH1A, 1986GI13, 1986GR1K, 1986HA34, 1986HA26, 1986IV1A, 1986KA1J, 1986KH03, 1986KI1D, 1986LAZL, 1986MC04, 1986MI25, 1986MO1M, 1986MO1J, 1986MO26, 1986NA03, 1986OS01, 1986OS1H, 1986OS03, 1986PE1L, 1986PE05, 1986PR1C, 1986PR01, 1986RA1J, 1986RO03, 1986SU18, 1986TA1T, 1986VO17, 1986VO1H, 1986WA26, 1986WH02, 1986YO05, 1986ZO1A, 1987AB12, 1987AB1E, 1987AG1C, 1987AL1I, 1987AL26, 1987AN14, 1987AP1A, 1987AR1P, 1987AS1E, 1987BA2Q, 1987BE2A, 1987BE2B, 1987BL07, 1987BO1D, 1987BO1E, 1987BO1X, 1987BU20, 1987CH21, 1987CH1N, 1987CH24, 1987CH29, 1987CL02, 1987CO20, 1987EJ02, 1987FA05, 1987GA08, 1987GA11, 1987GI01, 1987GI1B, 1987GI1C, 1987GM02, 1987GM04, 1987GU07, 1987GU1I, 1987HA40, 1987HE04, 1987HO08, 1987HU13, 1987JO1B, 1987KA39, 1987KH1B, 1987KO30, 1987LE1B, 1987LO1F, 1987MA1I, 1987MA1Z, 1987MO1M, 1987NA04, 1987PI1B, 1987RA1H, 1987ST1E, 1987WE1A, 1987WU1B, 1988AB05, 1988AB1G, 1988AM04, 1988BA2G, 1988BE1V, 1988BE2D, 1988BE2F, 1988BU16, 1988CH49, 1988CH24, 1988CH31, 1988CU1C, 1988DH1A, 1988ER04, 1988ER1B, 1988FR02, 1988FR1D, 1988FR10, 1988FR1J, 1988GIZU, 1988GO13, 1988GO08, 1988GO14, 1988GR1E, 1988HA07, 1988HA12, 1988EL06, 1988IT02, 1988JO1E, 1988KH01, 1988KIZW, 1988KY1A, 1988LE1G, 1988MA27, 1988MA37, 1988MO23, 1988OH04, 1988OS1A, 1988PE1F, 1988PO1H, 1988RA1H, 1988RO1M, 1988SA24, 1988SA31, 1988WI1B, 1988WI1I, 1988YOZZ, 1989AR1K, 1989BA06, 1989BA1R, 1989BRZX, 1989EJ1A, 1989EN1B, 1989GH1B, 1989GO09, 1989GR06, 1989HA07, 1989KH01, 1989MO1D, 1989NA01).

Kaons and other mesons-capture and reactions (see also 19reaction 35): (1983AK1A, 1983AR1F, 1983GE1C, 1983TO21, 1984AB04, 1984AL1H, 1984BA2L, 1984BA1M, 1984BO1H, 1984CO21, 1984GI1E, 1984IW1B, 1984MA1G, 1984SI13, 1984TO1B, 1984YA04, 1984ZO02, 1985AB1E, 1985BE31, 1985BE62, 1985CO1H, 1985CO14, 1985CO05, 1985DA1D, 1985DI06, 1985DO1G, 1985GA1E, 1985GA1C, 1985GR10, 1985IA01, 1985MI04, 1985SH1H, 1985SI09, 1985WA1N, 1985YA01, 1985YA07, 1985ZH13, 1985ZH11, 1986AB07, 1986AG1B, 1986BA3L, 1986BA81, 1986BE1P, 1986BE2J, 1986BE42, 1986BI1G, 1986CH1P, 1986CH1I, 1986CO1U, 1986DA1G, 1986DA1B, 1986DO1B, 1986FI1A, 1986GA33, 1986GA14, 1986GA1H, 1986HA1Y, 1986HA34, 1986HA26, 1986HA39, 1986HU1B, 1986KA1J, 1986KI1K, 1986KI1D, 1986KO2D, 1986MA1J, 1986MI1N, 1986MO1J, 1986PE1L, 1986TA11, 1986YA1T, 1986ZH1E, 1986ZO1A, 1987AP1A, 1987BEYQ, 1987BE14, 1987BE1S, 1987BL1L, 1987CH10, 1987EJ02, 1987FA1A, 1987HA40, 1987KO30, 1987LE1B, 1987PI1B, 1987PO1H, 1987SM1A, 1987WU1B, 1987WU05, 1988BA1F, 1988BR16, 1988CH49, 1988FA1B, 1988GA1A, 1988HA07, 1988HA41, 1988HA44, 1988KO36, 1988MA09, 1988MO1B, 1988MO14, 1988MO23, 1988PA1B, 1988PE1F, 1988PO1H, 1988RO11, 1988TA29, 1988TA14, 1988WA1B, 1988YA05, 1989BA06, 1989EJ1A, 1989HA07).

Hypernuclei: (1983SH1E, 1984AL1H, 1984AS1D, 1984BA1M, 1984BA1N, 1984BO1H, 1984MA1G, 1984MA1U, 1984MI1E, 1984SA1J, 1984ZO02, 1985AH1A, 1985GA1E, 1985GR10, 1985MI04, 1985OS1C, 1985WA1N, 1986BA3L, 1986BA1H, 1986AB81, 1986BI1G, 1986CO1U, 1986DA1G, 1986DA1B, 1986DO1B, 1986DU1M, 1986DU1P, 1986ER1A, 1986FE1A, 1986FR1J, 1986GA33, 1986GA14, 1986GA1H, 1986HA1Y, 1986HA34, 1986HA39, 1986HE01, 1986HU1B, 1986KO1A, 1986MI1N, 1986OS1G, 1986PE1L, 1986PO1H, 1986SZ1A, 1986YA1T, 1986ZO1A, 1987BA2K, 1987DA1F, 1987DA30, 1987DO1B, 1987EJ02, 1987MA08, 1987MA2A, 1987MI38, 1987PI1C, 1987PO1H, 1987RU1A, 1988BA1F, 1988BA1G, 1988BA82, 1988BO1P, 1988CH48, 1988DL1A, 1988GA1A, 1988GA1I, 1988GR1B, 1988HA07, 1988HA44, 1988MA09, 1988MA1G, 1988MO1B, 1988MO14, 1988MO23, 1988MO1L, 1988PE1F, 1988PO1H, 1988TA29, 1988WA1B, 1989BA06, 1989EJ1A, 1989KI25, 1989MR01).

Antinucleon interactions (see also reaction 38): (1984BA39, 1984CL1C, 1984DA1J, 1984DA23, 1984DO1E, 1984GA26, 1984KR22, 1984RI1D, 1984SA1M, 1984SU07, 1984VO1D, 1985AB1E, 1985BA09, 1985BA51, 1985CA16, 1985DA1D, 1985DA06, 1985DA24, 1985DA1G, 1985DO1E, 1985DU05, 1985HE24, 1985KU04, 1985KU08, 1985LI1J, 1985NA14, 1985PI14, 1985SU11, 1985VO06, 1986AU1D, 1986BA22, 1986BO26, 1986BU1J, 1986DI04, 1986DO20, 1986DU10, 1986FR10, 1986HE05, 1986IN01, 1986JA04, 1986MA46, 1986MC04, 1986MO1J, 1986SP01, 1986ZA06, 1987BA21, 1987BE26, 1987DA12, 1987DA1D, 1987GR1I, 1987HE04, 1987IS03, 1987MA04, 1987MA46, 1987SM1A, 1987VO1B, 1987YA1E, 1987ZA08, 1988DA07, 1988DE40, 1988GO13, 1988LI1O, 1988OK03, 1989AR1K, 1989CH13, 1989MA24, 1989MU1D).

Other topics: (1984CH1L, 1984CL11, 1984CO16, 1984GR18, 1984JE02, 1984LO05, 1984SH1X, 1985AN28, 1985AR07, 1985AR1B, 1985BU1F, 1985CI04, 1985KE1G, 1985KU22, 1985PA1M, 1985SHZL, 1985TH1D, 1986AL1T, 1986BE23, 1986BE39, 1986BI01, 1986DU06, 1986FO03, 1986KU11, 1986KE1P, 1986KU1B, 1986KU1P, 1986SA02, 1986SH2E, 1986WE1G, 1986YA1F, 1987AB21, 1987FUZZ, 1987HO07, 1987KU1I, 1987MO14, 1987PR01, 1987ZE05, 1988BO04, 1988FL1A, 1988HA38, 1988JA13, 1988KW02, 1988MO1H, 1988OH01, 1988OR1C, 1988OS1E, 1988RO18, 1988RU1B, 1989BA60, 1989CE01, 1989FI04, 1989JI04, 1989OR02, 1989RE1C, 1989RO01).

Ground-state properties of ¹²C: (1984AN1B, 1984BA2F, 1984BR25, 1984LO05, 1984RU12, 1985AN16, 1985AN28, 1985BE59, 1985CL1A, 1985GO1A, 1985KO02, 1985MI23, 1985OR01, 1985SA32, 1985SA30, 1985SH1A, 1985TA18, 1986AL1T, 1986AN35, 1986EL1A, 1986HE26, 1986KA2C, 1986KU1B, 1986LE16, 1986NI01, 1986RO03, 1986SA32, 1986SY1A, 1986WI04, 1987AB03, 1987AL05, 1987BL18, 1987BO42, 1987ER1F, 1987FU1D, 1987GI1C, 1987GU1C, 1987HA30, 1987JI01, 1987KI1C, 1987PR03, 1987RA01, 1987SA15, 1987ZE05, 1988BI1A, 1988CU1C, 1988DA1J, 1988DZ1A, 1988GU03, 1988HA38, 1988JO1C, 1988ME09, 1988OH01, 1988RA1G, 1988SP1A, 1988TA10, 1988VA03, 1988WO04, 1989BE03, 1989OR05, 1989RO01).

Isotopic abundance: (98.90 ± 0.03)% (1984DE53).

< r² > ^1/2 = 2.4829 ± 0.0019 fm (1984RU12; charge radius). See also reaction 32.

The interaction nuclear radius of ¹²C is 2.61 ± 0.02 fm (1985TA18). [See also for derived nuclear matter, charge and neutron matter r.m.s. radii.] See also (1989SA10).

¹²C*(4.44): Q = 6 ± 3 e · fm², indicating a substantial oblate deformation (1983VE01).

1. (a) ⁶Li(⁶Li, n) ¹¹C Q_m = 9.450 E_b = 28.171
(b) ⁶Li(⁶Li, p)¹¹B Q_m = 12.214
(c) ⁶Li(⁶Li, d)¹⁰B Q_m = 2.985
(d) ⁶Li(⁶Li, α)⁸Be Q_m = 20.805
(e) ⁶Li (⁶Li, 2α)⁴He Q_m = 20.897
(f) ⁶Li (⁶Li, 2d)⁴He⁴He Q_m = -2.950
(g) ⁶Li(⁶Li, ⁶Li)⁶Li

The excitation functions for some final states in ¹¹B and ¹¹C (reactions (a) and (b)) are structureless while others (to states with J^π = 3/2^-, 5/2^-, 5/2⁺) exhibit pronounced structures. The most prominent of these is observed at E(⁶Li) = 8.4 MeV [¹²C*(32.4)] in the p₂ and n₂ yields with a width Γ_c.m. ≈ 1 MeV (1987DO05). Reaction (d) has been studied for E(⁶Li) = 2.4 to 6.7 MeV in a kinematically complete experiment (1988LA11). See also (1984LA19, 1987LA25). For reactions (e) and (f) see (1983WA09). Broad structures have been observed in the elastic scattering at E(⁶Li) ≈ 13 and 26 MeV: see (19880AJ01). See also (1985AJ01), ⁶Li and ⁸Be in (1988AJ01), ¹¹B and ¹¹C here, (1985NO1A), (1988WE20) and (1988MC1E; applied).

2. ⁸Be(α, γ)¹²C Q_m = 7.36662

This reaction, of great importance to nucleosynthesis, has been studied by (1985CA41, 1986LA16, 1987DE13). See also the "General" section here.

3. ⁹Be(³He, γ)¹²C Q_m = 26.2790

Observed resonances are displayed in 12.8 (in PDF or PS). ¹²C*(28.2) appears to be formed by s- and d-wave capture. The γ₀ and γ₂ transitions to the 0⁺ states ¹²C*(0, 7.7) are strong and show a similar energy dependence. A strong non-resonant contribution is necessary to account for the γ₁ yield. The resonance structure appears to confirm the role of 3p3h configurations for ¹²C excitations somewhat above the giant resonance region. The γ₃ yield is relatively unstructured: see (1980AJ01). See also (1984MAZP, 1985BL1B).

4. (a) ⁹Be(³He, n)¹¹C Q_m = 7.557 E_b = 26.2790
(b) ⁹Be(³He, p)¹¹B Q_m = 10.3218
(c) ⁹Be(³He, d)¹⁰B Q_m = 1.0922
(d) ⁹Be(³He, t)⁹B Q_m = -1.087
(e) ⁹Be(³He, ³He)⁹Be
(f) ⁹Be(³He, α)⁸Be Q_m = 18.9124
(g) ⁹Be(³He, α)⁴He⁴He Q_m = 19.0043

Excitation functions for neutrons, production cross sections for ¹¹C and polarizations have been measured for E(³He) = 1.2 to 10 MeV for several neutron groups. No sharp structure is observed but there is some suggestions from angular distribution data and excitation functions at forward angles for a structure (Γ ≈ 350 keV) at E(³He) ≈ 2 MeV: E_x = 27.8 MeV. The total cross section for ¹¹C production shows a broad maximum, σ = 113 mb at E(³He) = 4.3 MeV. In the range E(³He) = 5.7 to 40.7 MeV it decreases monotonically. Excitation functions and angular distributions for protons (reaction (b)) have been measured for E(³He) = 1.0 to 10.2 MeV for a number of proton groups. No pronounced structures are reported. See also (1986SL1B; theor.).

Analyzing powers have been measured at E(pol. ³He) = 33.3 MeV for nine deuteron groups (reaction (c)). The cross section for ground-state tritons (reaction (d)) increases monotonically for E(³He) = 2.5 to 4.2 MeV and then shows a broad maximum at E(³He) ≈ 4.5 MeV.

The elastic scattering excitation function (reaction (e)) decreases monotonically for E(³He) = 4.0 to 9.0 MeV and 15.0 to 21.0 MeV. At θ_c.m. = 111° a slight rise is observed for E(³He) = 19 to 21 MeV. Polarization measurements have been reported at E(³He) = 18, 31.4 and 32.8 MeV.

Excitation functions for the α₀ group (reaction (f)) have been reported for E(³He) = 2 to 10 MeV. Analyzing powers have been measured at E(pol. ³He) = 33.3 MeV. For reaction (g) see (1986LA26, 1987WA25).

See also (1968AJ02, 1975AJ02, 1980AJ01, 1985AJ01) for references and for additional work, ¹¹B and ¹¹C here, and ⁸Be, ⁹Be, ⁹B and ¹⁰B in (1988AJ01).

5. ⁹Be(α, n) ¹²C Q_m = 5.7012

Neutron groups have been observed to ¹²C*(0, 4.4, 7.7, 9.6, (10.1), (10.8)). Angular distributions have been measured at many energies in the range E_α = 1.75 to 23 MeV [see (1968AJ02, 1975AJ02)] and at 28 and 32 MeV (1985GUZQ; prelim.; n_0→3). [The work at E_α = 35 MeV reported in (1985AJ01) has not been published: see, however, Fig. 1 in (1986AS02).] See also (1985CA41, 1988CA26; astrophysics) and (1986PH1C, 1987TC1A; applications).

6. ⁹Be(⁶Li, t)¹²C Q_m = 10.4835

At E(⁶Li) = 32 MeV angular distributions have been studied to ¹²C*(0, 4.4, 7.7, 9.6, 10.8, 11.8, 12.7, 14.1). There is no indication of the T = 1 states. ¹²C*(9.64) is relatively strongly populated (1986AS02; FRDWBA). See also (1980AJ01).

7. ⁹Be(⁹Be, ⁶He)¹²C Q_m = 5.103

See (1985AJ01).

8. ¹⁰Be(³He, n)¹²C Q_m = 19.4670

At E(³He) = 13 MeV neutron groups are observed to ¹²C*(0, 4.4, 7.7, 16.1, 17.8) and to excited states at E_x = 23.53 ± 0.04 [Γ < 0.4 MeV] and 27.611 ± 0.020 MeV. The latter is formed with a 0° cross section of ≈ 200 μb/sr and is taken to be the first 0⁺, T = 2 state of ¹²C (1974GO23).

9. ¹⁰B(d, γ)¹²C Q_m = 25.1868

The (d, γγ) excitation functions [via the J^π = 1⁺, T = 1 state at E_x = 15.1 MeV] has been measured for E_d = 2.655 to 2.91 MeV. The non-resonant yield of 15 MeV γ-rays is due to a direct capture process or to a very broad resonance: see (1975AJ02).

10. (a) ¹⁰B(d, n)¹¹C Q_m = 6.4650 E_b = 25.1868
(b) ¹⁰B(d, p)¹¹B Q_m = 9.2296

The thin-target excitation function in the forward direction (reaction (a)) in the range E_d = 0.3 to 4.6 MeV shows some indication of a broad resonance near E_d = 0.9 MeV. Above E_d = 2.4 MeV, the cross section increases rapidly to 210 mb/sr at 3.8 MeV, and then remains constant to 4.6 MeV. Excitation functions have also been measured for E_d = 3.2 to 16.0 MeV. Thick target yields for 4.3 MeV γ-rays for E_d = 111 to 170 keV have also been studied and astrophysical S-factors have been calculated. In reaction (b) yields of protons have been measured for E_d = 91 keV to 12 MeV: no clear resonance structure is observed.

See also ¹¹B, ¹¹C here and (1968AJ02, 1975AJ02, 1985AJ01).

11. ¹⁰B(d, d)¹⁰B E_b = 25.1868

The yield of elastically scattered deuterons has been measured for E_d = 1.0 to 2.0 MeV (there is some suggestion of resonances) and for E_d = 14.0 to 15.5 MeV. Excitation functions for the deuterons to ¹⁰B*(1.74, 2.15) [J^π; T = 0⁺; 1 and 1⁺; 0, respectively] have been measured at several angles for E_d = 4.2 to 16 MeV: they are characterized by rather broad, slowly varying structure: see (1980AJ01) [see also for polarization measurements]. See also ¹⁰B in (1988AJ01).

12. ¹⁰B(d, α)⁸Be Q_m = 17.8202 E_b = 25.1868

Excitation functions have been measured for the α₀ and α₁ groups for E_d = 0.4 to 12 MeV. Broad maxima in the α₀ yield are reported at E_d ≈ 1 (Γ ≈ 0.5), 2 and 4.5 MeV (Γ ≳ 1 MeV) as well as, possibly, at 6 MeV. Involvement of the isoscalar giant quadrupole resonance [E_x ≈ 28 MeV, Γ ≈ 4 MeV] is suggested: see (1980AJ01). See also ⁸Be in (1988AJ01) and (1988KA1M; theor.).

13. (a) ¹⁰B(³He, p)¹²C Q_m = 19.6933
(b) ¹⁰B(³He, pα)⁸Be Q_m = 12.3267

12.9 (in PDF or PS) displays the proton groups observed in this reaction , and the work on their α-decay.

For a study of the charge-dependent matrix element between ¹²C*(12.7, 15.1) see 12.10 (in PDF or PS).

14. ¹⁰B(α, d)¹²C Q_m = 1.3401

Angular distributions have been measured at E_α = 15.1 to 25.2 MeV [see (1980AJ01)], 29.5 MeV (1983VA28; d₀, d₁) and 31.2 MeV (1984KO1Q; d₀, d₁). For dγ_4.4 angular correlation studies see (1987VA04, 1988IG04, 1988VA1D). See also (1984BE23; theor.).

15. ¹⁰B(⁶Li, α)¹²C Q_m = 23.7118

At E(⁶Li) = 4.9 MeV angular distributions have been obtained for the α-particles to ¹²C*(0, 4.4, 7.7, 9.6). The population of ¹²C*(11.8, 12.7) is also reported, as is that of ¹²C*(15.11) [T = 1]: see (1975AJ02).

16. ¹⁰B(¹⁴N, ¹²C)¹²C Q_m = 14.9144

Angular distributions involving ¹²C*(0, 4.4) have been measured at several energies, to E(¹⁴N) = 93.6 MeV: see (1980AJ01). See also (1984MA1R).

17. (a) ¹¹B(p, γ)¹²C Q_m = 15.9572
(b) ¹¹B(p, α)⁸Be Q_m = 8.5906 E_b = 15.9572
(c) ¹¹B(p, α)⁴He⁴He Q_m = 8.6825

In view of the complexity of the availiable information on these three reactions, we will first summarize the experimental results and then review the evidence for the parameters of ¹²C states observed as resonances: see 12.11 (in PDF or PS). See (1975AJ02, 1980AJ01) for references.

(a) In the range 4 < E_p < 14.5 MeV σ(γ₀) is dominated by the great dipole resonance at E_p = 7.2 MeV (E_x = 22.6 MeV, Γ_c.m. = 3.2 MeV), while the giant resonance in γ₁ occurs at E_p ≈ 10.3 MeV (E_x = 25.4 MeV, Γ_c.m. ≈ 6.5 MeV). Absolute cross section measurements from E_p = 5 to 14 MeV suggest that dσ/dΩ (90°)_L = 13.1 ± 1.3 μb/sr be used as a standard at the E_p = 7.25 MeV peak of the GDR.

A study of the giant dipole resonance region with polarized protons (E_p = 6 to 14 MeV) sets new limits on the configuration mixing in the γ₀ giant resonance. The analysis of γ₁ is more complicated: the asymmetry results are consistent either with a single J^π = 2^- state or with interference of pairs of states such as (1^-, 3^-), (2^-, 3^-) and (1^-, 2^-). The 90° yield of γ₀, γ₁, γ₂ and γ₃ [to ¹²C*(0, 4.4, 7.7, 9.6)] has been studied by (1977SN01): the γ₂ yield shows a peak at E_p ≈ 14.3 MeV with a cross section ≈ 2.3% that of γ₀ [in γ₀ yield, E_res = 15.0 MeV (1977SN01)] and perhaps as well a low intensity structure at E_p = 11.8 MeV. The γ₃ yield exhibits two asymmetric peaks at E_p = 12.5 and 13.8 MeV (Γ ≈ 0.7 and 2.5 MeV) and a weaker structure at ≈ 9.8 MeV (1977SN01).

At E_{pol. p} = 50 MeV, angular distributions and analyzing power measurements are reported to ¹²C*(0, 4.4, 9.6, 18.8 ± 0.5 [u], 22.3 ± 1.0 [u]) by (1985NO01) [u = unresolved]. Measurements are also reported at E_{pol. p} = 28.5 MeV (1984BL10) and 40 to 80 MeV (1986EJ1A, 1986SH1Y; prelim., γ₀, γ₁). (1988HA04) have studied the γ₀ group for E_{pol. p} = 20 to 100 MeV. See also (1985HA05). In earlier work (1982WE08) studied the γ₀ and γ₁ yields for E_p = 8 to 60 MeV and the γ₁₉ yield for E_p = 23 to 60 MeV. Giant resonances based on various states of ¹²C have been reported at E_x = 22.5 and 25.5 MeV [γ₀], 25.5, 27.4 and (31) MeV [γ₁], 27.4, 31 and (37) MeV [γ₃], as well as in the γ-yield to higher states: see (1985AJ01). The γ₁₉ yield shows a structure at E_p ≈ 43 MeV (1983AN16; E_p = 18 to 45 MeV; also γ to ¹²C*(0, 4.4, 9.6, 12.7 [u], 15.5 [u]).

(b) Excitation functions have been measured for E_p = 3.0 to 24 MeV: see (1980AJ01, 1985AJ01) and 12.11 (in PDF or PS) and 12.12 (in PDF or PS) here.

(c) This reaction has been studied at energies to 20 MeV. The cross sections for the reactions vie ⁸Be_g.s. and ⁸Be*(2.9) [α₀, α₁] have been determined for E_c.m. = 22 to 1100 keV. The total cross section shows the 162 keV resonance and a broad peak centered at 600 keV. At E_c.m. = 300 keV σ(α₀) = 1.03 ± 0.06 mb and σ(α₁) = 165 ± 10 mb (1987BE17). The parameters of the 162 keV resonance are E_res(c.m.) = 148.3 ± 0.1 keV, Γ_c.m. = 5.3 ± 0.2 keV (1987BE17), 149.8 ± 0.2 keV, 5.2^+0.5_-0.3 keV (1979DA03). Derived S-values lead to S(0) = 197 ± 12 MeV · b (1987BE17). This reaction is of possible interest for fusion reactors.

See also ⁸Be in (1988AJ01), (1985NO1G, 1986KU18), (1984BR1L, 1984SN01, 1985DO1F, 1986SN1B, 1986WE1D, 1988HA1W), (1983SG1B, 1984HA1J, 1986KA1U, 1986PR1D, 1986ZI01, 1988KI1C; applications), (1983HA1B, 1984YA1A, 1985CA41, 1987AS05, 1988CA26; astrophysics) and (1984CA18, 1984SE16, 1985GO1B, 1985KI16, 1985RA10, 1987AS05, 1987KI1C, 1987KO1X; theor.).

The parameters of the observed resonances are displayed in 12.11 (in PDF or PS). The following summarizes the information on the low-lying resonances: for a full list of references see (1968AJ02, 1980AJ01, 1985AJ01).

E_p= 0.16 MeV [¹²C*(16.11)]. This is the J^π = 2⁺; T = 1 analog of the first excited states of ¹²B and ¹²N. The γ-decay is to ¹²C*(0, 4.4, 9.6), and also ¹²C*(12.71) [see 12.7 (in PDF or PS)]: the angular distribution of γ₃, together with the known α-decay of ¹²C*(9.6), fix J^π = 3^- for the latter.

E_p= 0.67 MeV [¹²C*(16.57)]. The proton width [Γ_p ≈ 150 keV] indicates s-wave protons and therefore J^π = 1^- or 2^-. This is supported by the near isotropy of the two resonant exit channels, α₁ and γ₁. The α₁ cross section indicates 2J + 1 ≥ 5: therefore J^π = 2^-. [This is consistent with the results of an αα-correlation study via ⁸Be*(2.9)]. The γ₁ E1 transition has |M|² ≈ 0.1 W.u., suggesting T = 1.

E_p= 1.4 MeV [¹²C*(17.23)]. (2J + 1)Γ_γ₀ ≥ 115 eV. This indicates J^π = 1^-, with T = 1 most probable. J^π = 1^- is also required to account for the interference at lower energies in α₀ and γ₀ and is consistent with the αα-correlation results. Two solutions for Γ_p are possible; the larger (chosen for 12.11 (in PDF or PS)) is favored by elastic scattering data.

E_p= 2.0 MeV [¹²C*(17.8)]. The resonance in the yield of α₀ requires natural parity, the small α-widths suggest T = 1. For J^π = 1^- or 3^- the small γ-widths would be surprising; J^π = 2⁺ would lead to a larger anomaly than is observed. J^π is then 0⁺, T = 1. (1982HA12) [E_p = 0.82 to 2.83 MeV] report E_x = 17.80 MeV [Γ_c.m. = 96 ± 5 keV] decays via a 5.10 ± 0.03 MeV γ-ray to ¹²C*(12.71): Γ_γ = 3.7 ± 1.5 eV. The angular distribution is isotropic, as expected.

E_p= 2.37 MeV [¹²C*(18.13)]. Seen as a resonance in the yield of 15.1 MeV γ-rays: σ_R = 0.77 ± 0.15 μb, Γ_c.m. = 600 ± 100 keV, (2J + 1) Γ_γ ≥ 2.8 ± 0.6 eV. The results are consistent with J^π = 1⁺, T = 0, but interference with a non-resonant background excludes a definite assignment.

E_p= 2.62 MeV [¹²C*(18.38)]. The resonance for α₀ requires natural parity; the presence of a large P₄ term in the angular distribution requires J ≥ 2 and l_p ≥ 2. (1982HA12) report E_x = 18.38 MeV, Γ_c.m. ≈ 400 keV, Γ_γ (to ¹²C*(9.6)) = 5.7 ± 2.3 eV, consistent with J^π = 3^-; T = 1. The total peak cross section is 4.2 ± 1.7 μb. Transitions to ¹²C*(0, 4.4) are also observed: Γ_γ ≈ 2 × 10^-3 eV and 3.2 ± 1.0 eV, respectively.

E_p= 2.66 MeV [¹²C*(18.39)] is not seen here: see ¹¹B(p, p).

E_p= 3.12 MeV [¹²C*(18.81)]. The angular distribution of γ₀ indicates E2 radiation, J^π = 2⁺. This assignment is supported by the angular correlation in the cascade γ₁ and by the behavior of σ(α₀); T = 1 is suggested by the small Γ_α. The yield of γ₃ (to ¹²C*(9.6)) shows a peak corresponding to E_x ≈ 18.9 - 19.0 MeV. It may be due to ¹²C*(18.8) with an energy shift due to interference.

The structure near E_p = 3.5 - 3.7 MeV [¹²C*(19.2, 19.4)] seems to require at least two levels. The large Γ_γ₀ requires that one be J^π = 1^-, T = 1 and interference terms in σ(α₀) require another to have even spin and even parity: J^π = 2⁺, T = 0 is favored. (1982WR01) report that they do not observe any evidence for an isospin mixed doublet near E_x = 19.5 MeV [E_p = 2.9 to 4.6 MeV (60° and 90°)]. Resonances at E_p = 4.93 and 5.11 MeV, seen in σ(γ₁) also appear in σ(α₁), but not in σ(α₀). Angular distributions suggest J^π = 2⁺ or 3^- for the latter [¹²C*(20.64)]; the strength of γ₁ and absence of γ₀ favors J^π = 3^-, T = 1.

The first seven T = 1 states in ¹²B and ¹²C have been identified by comparing reduced proton widths obtained for this reaction and reduced widths obtained from the (d, p) and (d, n) reactions: see 12.12 (in PDF or PS) in (1980AJ01).

18. ¹¹B(p, n)¹¹C Q_m = -2.7646 E_b = 15.9572

Excitation functions have been studied from threshold to 27.5 MeV [see (1980AJ01, 1985AJ01)] and at E_p = 13.7 to 14.7 MeV (1985SC08; n₀ → n₃, n₄₊₅, n₆, n₇) and 16 to 26 MeV (1985GR09; n₀ → n₃). See also (1986AI04). At the lower energies many resonances are observed: see 12.12 (in PDF or PS).

Polarization measurements have been carried out for E_{pol. p} = 7.0 to 26.5 MeV [see (1980AJ01, 1985AJ01)]. For high-energy interactions see (1984BA1R, 1984BA1U). See also ¹¹C, (1989RA09), (1985CA41; astrophysics) and (1985RA10; theor.).

19. (a) ¹¹B(p, p)¹¹B E_b = 15.9572
(b)¹¹B(p, d)¹⁰B Q_m = -9.2296

Anomalies and maxima observed in the excitation functions of p₀ → p₃ are displayed in 12.12 (in PDF or PS). Studies of the scattering have been reported at E_p = 1.8 to 47.4 MeV [see (1980AJ01, 1985AJ01)] and at E_c.m. ≈ 0.15 to 1.1 MeV (1987BE17; p₀). A study of the yield of γ-rays is reported to lead to ¹²C*(18.98, 19.93, 20.63) (1988ABZW; prelim.). A review of the evidence on the states with 20.2 < E_x < 22.5 MeV suggests that in all the channels and throughout this energy range a strong 2⁺ background is observed, which may be the low-energy tail of the isoscalar giant quadrupole resonance (1983BO19). For polarization measurements [E_p = 1.9 to 155 MeV] see (1975AJ02, 1980AJ01, 1985AJ01). For reaction (b) see (1985AJ01) and ¹⁰B in (1988AJ01). For studies of high-energy interactions see (1984BA1U, 1984BA1T). See also (1985MUZZ), (1986BA88) and (1985RA10, 1987RA14; theor.).

20. ¹¹B(d, n)¹²C Q_m = 13.7326

Reported neutron groups are displayed in 12.13 (in PDF or PS). Angular distributions have been studied for E_d = 0.5 to 12 MeV [see (1968AJ02, 1975AJ02, 1985AJ01)] and at E_{pol. d} = 79 MeV (1985FO05, 1987FO22); to ¹²C*(0, 4.4, 9.6, 12.7, 15.1; DWBA-EFR). For polarization measurements see (1987FO22, 1986FO08) and ¹³C in (1991AJ01). For angular correlation studies see (1980AJ01) and (1985NE01) [ 12.13 (in PDF or PS)].

21. ¹¹B(³He, d) ¹²C Q_m = 10.4637

Observed deuteron groups are displayed in 12.13 (in PDF or PS). Angular distributions have been studied at E(³He) = 5.1 to 44 MeV [see (1975AJ02, 1980AJ01)] and at 18.3 and 22.3 MeV (1988IG03; d₀, d₁; also d₁γ angular correlations). See also (1987BA2B, 1987ZE02; theor.).

22. ¹¹B(α, t)¹²C Q_m = -3.8568

Angular distributions have been studied in the range E_α = 15.1 to 120 MeV [see (1980AJ01, 1985AJ01)] and at E_α = 30.1 (1983VA28; t₀, t₁, t₂) and 31.2 MeV (1984KO1Q; t₀, t₁). Angular correlation measurements (t₁, γ) are reported at E_α = 21 to 30 MeV: see (1987VA04, 1988IG04, 1988VA1D). See also (1987LE33) and (1984BE23, 1985ZE04, 1987BA2B, 1987ZE02, 1989BA90; theor.).

23. ¹¹B(⁷Li, ⁶He)¹²C Q_m = 5.9826

At E(⁷Li) = 34 MeV, angular distributions have been measured for the groups to ¹²C*(0, 4.4, 7.7, 9.6, 10.8, 11.8, 12.7, 15.1, 16.1, 18.35) (1983NE11). It is concluded on the basis of this and other work, that the group corresponding to E_x = 18.35 ± 0.05 MeV (Γ = 350 ± 50 keV) consists of unresolved states with J^π = 3^- (T = 1) and 2^- (T = 0 plus some mixing of T = 1) (1983NE11; see for spectroscopic factors): no states were observed with E_x > 18.35 MeV. See also (1987CO16, 1988BEYJ).

24. ¹¹B(¹¹B, ¹⁰Be)¹²C Q_m = 4.7293

Angular distributions involving ¹²C*(0, 4.4) and ¹⁰Be*(0, 3.4) have been measured at E(¹¹B) = 11 MeV (1985PO02).

25. (a) ¹¹B(¹⁴N, ¹³C)¹²C Q_m = 8.4066
(b) ¹¹B(¹⁶O, ¹⁵N)¹²C Q_m = 3.8297

See (1980AJ01). See also (1984CL09; theor.).

26. ¹²B(β^-)¹²C Q_m = 13.370

The decay is mainly to ¹²C_g.s.; branching ratios to ¹²C*(0, 4.4, 7.7, 10.3) are displayed in 12.14 (in PDF or PS). All the observed transitions are allowed. The half-life is 20.20 ± 0.02 ms (1978AL01).

¹²C*(7.7) [J^π = 0⁺] is of particular interest for helium burning processes in stars: Γ_rad = 3.41 ± 1.12 meV. A search for transitions to ¹²C*(12.7) has been unsuccessful: see (1968AJ02, 1975AJ02). The shapes of the β-spectra of ¹²B and ¹²N have been analyzed.

The results are in agreement with CVC and with the absence of second-class induced tensor currents: see (1980AJ01). See also reaction 60 here.

27. (a) ¹²C(γ, n)¹¹C Q_m = -18.722
(b) ¹²C(γ, 2n)¹⁰C Q_m = -31.8419

The total absorption, mainly (γ, n) + (γ, p), is dominated by the giant resonance peak at 23.2 MeV, Γ = 3.2 MeV [σ_max = 21 mb] and by a smaller structure at 25.6 MeV, Γ ≈ 2 MeV [σ_max ≈ 13 mb]: see (1968AJ02, 1975AJ02, 1980AJ01) for a detailed listing of the earlier references and results. See also (1984GH1A, 1985GH1B).

The (γ, n) cross section shows a giant resonance, σ_max ≈ 7 - 8 mb, centered at about 23 MeV and consisting of an ≈ 1 MeV-wide group at 22.3 MeV and an ≈ 2 MeV-wide group at ≈ 23.3 MeV. A secondary maximum occurs at 25.5 MeV, Γ ≈ 2 MeV. There is also evidence of other structure at ≈ 30 - 31 and possibly at ≈ 35 MeV: see (1988DI02) and B.L. Berman, private communication.

The (γ, n₀) cross section has been measured at 90° for 21 < E_x < 40 MeV and compared with the (γ, p₀) cross section: the isospin mixing averages about 2% in intensity and shows structure at the giant resonance. Angular distributions of n₀ measured over the giant resonance region indicate that the main excitation mechanism is of a 1p_3/2 → d_5/2 E1 single-particle character. No significant E2 strength is observed: see (1980AJ01). Differential cross sections at θ_lab = 65° have been measured for the n₀₊₁ and n_2→9 groups for E_γ = 33.7 to 99.4 MeV (1988HA01). See also the discussion in (1985FU1C).

The (γ, 2n) cross section (reaction (b)) is very much smaller than that for (γ, n): the highest value is 0.15% of the maximum value for reaction (a) in the energy range E_γ = 20 to 140 MeV: see (1980AJ01, 1985AJ01). See also (1985AH06, 1985GI1G, 1985HO27, 1985PY01), (1989BO1F; astrophysics) and (1984CA18, 1984MO13, 1984VA1G, 1985BO12, 1985GO1A, 1985KO2K, 1985VA1C, 1986VA14, 1987BR21, 1987FE05, 1987GO37, 1987KI1C, 1987VA35, 1988CO1G; theor.).

28. (a) ¹²C(γ, p)¹¹B Q_m = -15.9572
(b) ¹²C(γ, π^0)¹²C Q_m = -134.964

The photoproton cross section exhibits two broad peaks, the giant resonance peak at 22.5 MeV, Γ = 3.2 MeV, σ_max = 13.1 ± 0.8 mb and a 2 MeV broad peak at 25.2 MeV, σ_max = 5.6 ± 0.3 mb: see (1976CA21) and 12.19 (in PDF or PS) in (1968AJ02). The (γ, p₀) cross section at the giant resonance is 11.0 ± 1.1 mb (1986KE06). While the E1 component dominates in the GDR, a 2% E2 contribution may possibly be present (1976CA21). In contrast with the giant resonance peak in the (γ, n) cross section, the (γ, p) cross section shows a strong peak in the center of the broad giant resonance peak. Above 24.5 MeV the ground state (γ, p) and (γ, n) excitation functions have the same shape up to at least 36 MeV: see (1985FU1C). There is agreement between the (γ, p) results and those from the inverse reaction ¹¹B(p, γ₀) [see reaction 17] when the population of ¹¹B*(4.4, 5.0) is taken into account. See also ¹¹B and (1986AN25, 1986MC15, 1988SH08). At E_γ = 28 MeV the branching ratios to ¹¹B*(0, 2.12, 4.4 + 5.0) are, respectively, (76 ± 4)%, (13 ± 1.3)% and (11 ± 1.2)% (1989FE01). See also reaction 30. For the proton momentum spectrum at E_γ = 357 ± 10 MeV see (1984HO24). For the cross section with polarized photons with E_γ = 41.2 to 93.0 MeV see (1988YO1A). For measurements in the Δ-resonance region see (1987KA13).

The photoproduction of neutral pions (reaction (b)) has been studied from threshold to 450 MeV [see (1985AJ01)] and at E_γ = 132 to 169 MeV (1989KO05), 138 to 146 MeV (1986GL07, 1987GL01), 138.0 to 181.9 MeV (1987JA1F, 1987MA07) and 234 to 449 MeV (1986AR06). At E_γ = 157 to 170 MeV the excitation of ¹²C*(4.4) is reported (1989PF1A; prelim.). See also (1989KO1Q) and (1984HO24, 1988ST12). For other papers on pion production (including π⁺ and π^-) see the "General" section here, and ¹²B and ¹²N. For high energy processes see (1984AL1J, 1984AL1K).

See also (1985AJ01), (1983AR24, 1983TO18, 1984ST18, 1986SH1M, 1988SC1B), (1985GI1G, 1985HO27, 1985MA1G, 1988OC1A), (1989BO1F; astrophysics) and (1984BO18, 1984CA18, 1985AL1K, 1985BO1A, 1985TO15, 1986HO11, 1987BE2A, 1987GOZK, 1987GO37, 1987KI1C, 1987PA1K, 1988AH03, 1988OR02; theor.).

29. (a) ¹²C(γ, d)¹⁰B Q_m = -25.1868
(b) ¹²C(γ, pn)¹⁰B Q_m = -27.4114
(c) ¹²C(γ, pd)⁹Be Q_m = -31.7726
(d) ¹²C(γ, t)⁹B Q_m = -27.366

Cross sections and angular distributions of the deuterons corresponding to transitions to ¹⁰B_g.s. and/or low excited states have been measured at E_γ ≈ 40 MeV: the results are consistent with E2. There is some evidence also for the excitation of higher states of ¹⁰B via non-E2 transitions. For E_bs = 90 MeV, the ratio of the yields of deuterons to protons is ≈ 2%, for particle energies 15 to 30 MeV. For higher particle energies, the ratio decreases: see (1980AJ01) for references. See also (1986SH1M). Momentum spectra for deuterons and tritons (reactions (a) and (d)) are reported at E_γ = 300 to 600 MeV by (1986BA07). The (γ, pn) reaction has been studied at E_γ = 83 to 133 MeV by (1988DA16) and in the Δ-resonance region by (1987KA13). For reaction (c) see (1987VO08). The yield of tritons has been measured for E_γ = 35 to 50 MeV: see (1980AJ01). See also (1985AJ01), (1984AL1J, 1984DO17) and (1985BU1H, 1986BU22, 1986GU1G, 1987BU1A; theor.).

30. ¹²C(γ, α)⁸Be Q_m = -7.3666

The cross section exhibits broad peaks at about 18 MeV and ≈ 29 MeV; a pronounced minimum occurs at 20.5 MeV: to what extent the peaks have fine structure is not clear. For E_γ < 22 MeV, transitions are mainly to ⁸Be(g.s.) and ⁸Be*(2.9) with the g.s. transition dominating for E_γ ≲ 14 MeV. For E_γ > 26.4 MeV, ⁸Be (T = 1) levels near 17 MeV are strongly excited. Surprisingly strong E1 contributions are observed below E_γ ≈ 17 MeV: see (1980AJ01) for references. See also (1986LI22). The ratio for σ(γ, α₀)/σ(γ, p₀) is 0.029 ± 0.012 at E_γ = 28 MeV (1989FE01). For other breakup processes see (1975AJ02, 1985AJ01). See also (1985CH27; theor.).

31. ¹²C(γ, γ)¹²C

Resonance scattering and absorption by ¹²C*(15.11) have been studied by many groups: see (1980AJ01) and 12.7 (in PDF or PS) here. Inelastic scattering has also been reported to ¹²C*(4.4, 9.6 ± 0.2, 11.8 ± 0.2, 12.7, 13.3 ± 0.2, 17.2 ± 0.2, 18.3 ± 0.2, 20.5 ± 0.2, 22 - 24 (giant resonance), 26.5 ± 0.4, 29.5 ± 0.3): see (1980AJ01, 1985AJ01). Measurements of the elastic differential cross sections for E_γ = 22.5 to 52.0 MeV (θ = 45°, 90°, 135°) have been reported by (1985WR02). The difference between the (measured) energy-integrated values of σ_γ and the E1 part of the photoabsorption cross section σ^E1_γ is small and cannot be ascribed to E2 strength (1985WR02). Beyond E_γ = 52 MeV significant E2 strength may be present (1985WR02). For the earlier work see (1985AJ01). See also (1984NA18, 1986BEZM), (1984NA1J, 1985HA1H, 1985MU08) and (1984MA1W, 1985AR07, 1985VE09, 1987FE05, 1987VE03; theor.).

32. ¹²C(e, e)¹²C

Recent values of the nuclear charge radius are < r² > ^1/2 = 2.472 ± 0.015 fm, 2.464 ± 0.012 fm [2.468 ± 0.012 fm when the dispersion correction is made]: see (1985AJ01). A value obtained from muonic X-rays is displayed in the "General" section here. Elastic scattering has been studied up to 4 GeV: see (1968AJ02, 1975AJ02, 1985AJ01). (1986OF01, 1987OF1A) report evidence for an energy dependence of the elastic form factors, probably due to two-step processes, between E_e = 238 and 431 MeV.

¹²C states observed in inelastic scattering are displayed in 12.15 (in PDF or PS). The variation of the form factor with momentum transfer yields unambiguous assignments of J^π = 2⁺, 0⁺, and 3^- for ¹²C*(4.4, 7.7, 9.6). Longitudinal form factors show ¹²C*(16.1, 18.6, 20.0, 21.6, 22.0, 23.8, 25.5) while the transverse form factors show ¹²C*(15.1, 16.1, 16.6, 18.1, 19.3, 19.6, 20.6, 22.7, (25.5)). ¹²C*(19.4) may be the expected giant magnetic quadrupole state, J^π = 2^-: see (1975AJ02, 1980AJ01) for references and additional information. The more recent work by (1984HI06, 1987HI09) is also displayed in 12.15 (in PDF or PS). A study of the (e, e'γ) reaction by (1985PA01) shows that the relative phase of the longitudinal and transverse form factors of ¹²C*(4.4) is negative. Studies of the excitation of the Δ-resonance are reported by (1987OC01; E_e = 537 and 737 MeV) and by (1988BA25; E_e = 653, 1300, 1500, and 1650 MeV). See also (1986OLZY, 1986TH1F, 1987GI1G).

33. ¹²C(e, ep)¹¹B Q_m = -15.9572

I am extremely indebted to Dr. Larry Weinstein for his detailed comments which led to the writeup below.

The inclusive studies by (1983BA28, 1984AR02, 1984OC01) uncovered a lack of understanding of the quasielastic and dip region processes. The more recent studies have focused on (a) quasielastic processes involving various states of ¹¹B [see ¹¹B and (1985VA05, 1985VA16, 1988VA09, 1988VA21)]; (b) quasielastic reaction mechanism studies including longitudinal/transverse separations (1986VA17, 1987UL03, 1988VA09, 1988WE1E); (c) dip and Δ-region reaction mechanism studies (1986LO03, 1989BA03, 1989SE02); and (d) quasifree deuteron knockout spectroscopy to low-lying states of ¹⁰B (1989EN01). See also (1987DA20, 1988AV01).

Nuclear spectroscopy studies produce momentum distributions that are well reproduced by DWIA calculations but with occupation numbers that are about 60% of the expected shell-model results (1985VA05, 1985VA16, 1988VA09, 1988VA21, 1987UL03, 1988WE1E).

Studies of the quasielastic longitudinal and transverse response functions versus missing energy have been carried out by (1986VA17, 1987UL03, 1988VA09). See also (1988VA1I, 1988VA1J). (1987UL03) find in the longitudinal response a broad bump at missing energies between 28 and 48 MeV, attributed to knockout from the s-shell. In the transverse response they find this bump on top of a broader feature with a threshold at 28 MeV extending beyond 65 MeV. This broad feature is attributed to two-particle knockout, a non-quasielastic reaction mechanism; it may account for the observed (e, e') transverse-longitudinal difference. This feature is also observed in unseparated data at larger momentum transfers: it appears to grow with momentum transfer (1988WE1E).

(1984CA34) find evidence from the (e, ep₀) work for a monopole, 0⁺, state near E_x ≈ 20.5 MeV which exhausts at least 1% of the EWSR. The decay of states in the giant resonance region via α-particles has been studied by (1987DEZU): the decay is primarily to ⁸Be*(2.9) (J^π = 2⁺). See also (1984FL02, 1986LI22). For other charged particle emission see (1984FL02). For pion emission see the "General" section here, ¹²B, ¹²N and (1986SH14, 1988SH36). For the early work see (1980AJ01, 1985AJ01).

34. (a) ¹²C(π^±, π^±)¹²C
(b) ¹²C(π^±, π^±p)¹¹B Q_m = -15.9572

Angular distributions of the elastic and inelastically scattered pions have been measured at many energies: see 12.16 (in PDF or PS) in (1985AJ01) and 12.16 (in PDF or PS) here. The study by (1987CO17) [E_π^± = 100 to 291 MeV] suggests J^π = 2^- for ¹²C*(18.25, 19.4) and 4 for ¹²C*(19.25). ¹²C*(19.65) is also populated. A study of the giant resonance region suggests states at E_x = 20.0 ± 0.2 and 22.7 ± 0.4 MeV, with Γ = 3.2 ± 0.3 and 1.0 ± 0.2 MeV (1984BL12; E_π⁺ = 170 MeV).

The ratio of the cross sections to the 1⁺; T = 0 and 1⁺; T = 1 states, ¹²C*(12.7, 15.1), has been measured at E_π^± = 50 MeV, where it is 7.1 ± 1 [isospin averaged] (1988RI03). The excitation of these two states has also been studied for E_π^± = 80 to 295 MeV by (1988OA03). See also (1988BA27). (1986AN01) have reported inelastic cross sections, including those to the "continuum" above ¹²C*(9.6) at E_π⁺ = 67, 85 and 100 MeV. The elastic excitation function at θ = 175° has been measured for E_π⁺ = 100 to 250 MeV (1987DH01). Total reaction cross sections are reported at E_π^± = 50 and 65 MeV (1987ME12). See also (1987BE1R).

(π', γ_4.4) angular correlations have been studied at E_π⁺ = 65 and 90 MeV (1984SO12) and 116 to 226 MeV (1986OL07, 1988OL02). See also (1985KI05). The (π', γ_15.1) angular correlations are reported at E_π⁺ = 116 to 226 MeV (1988BA27).

For reaction (b) see ¹¹B and (1984FA11; E_π^± = 220 MeV) and (1987HU02; E_π⁺ = 150 MeV). The polarization of protons in the π^± A → px process has been studied at 1.5 GeV/c (1984BU11). For studies of (π^±, 2p), (π⁺, pd), and (π^±, pn) reactions see (1986AL22, 1986NA03, 1987YO01, 1989YO03). For the (π⁺, 3p) reaction see (1985TA14, 1987BR17). See also the "General" section here, (1985AJ01) for the earlier work, (1984GO1F, 1989ROZZ), (1984KI16, 1985MI16) and (1985CO03, 1985KA04, 1986PE1E, 1986TA08, 1988ST07; theor.).

35. ¹²C(K^±, K^±)¹²C

At E_K^± = 442 MeV angular distributions have been obtained for ¹²C*(0, 4.4, 9.6) (1982MA16). See also the "General" section here, (1988AF02) and (1988BR16; theor.).

36. (a) ¹²C(n, n)¹²C
(b) ¹²C(n, nα)⁸Be Q_m = -7.3666

Angular distributions of elastic and inelastically scattered neutrons have been studied at many energies up to 350 MeV [see (1980AJ01, 1985AJ01)] and at E_n = 11.05 and 13.81 MeV (1986HOZY; prelim.; n₀, n₁), 14.1 and 14.5 MeV (1983HU14; n₀, n₁), 14.6 MeV (1985HA02; n₀), 18.2 MeV (n₀; quoted in (1987TO03)), 20.8, 22, 24 and 26 MeV (1985ME16; to ¹²C*(0, 4.4, 7.7, 9.6, 10.8, 11.8, 13.4, 14.1, 15.1, 16.1 [the latter two at E_n = 22 and 24 MeV (A.S. Meigooni, Ph.D. Thesis, Ohio University (1984) and R.W. Finlay, private communication)]) and 40.3 MeV (1986WI01; n₀). See also (1985FI09) and (1985PE10; theor.). For cross sections and polarization studies see (1985TO02, 1987TO07, 1987TO03, 1988TO01) and ¹³C in (1991AJ01).

Angular correlations (n₁, γ_4.4) have been studied at E_n = 13.9 to 15 MeV: see (1975AJ02). The quadrupole deformation parameter β₂ = -0.67 ± 0.04 (1983WO02). For a kinematically complete study of reaction (b) at E_n = 11 to 35 MeV see (1983AN02): the sequential decay via ¹²C*(9.6) and ⁸Be_g.s. is clearly observed at the higher energies. See also (1986AN22) and (1980AJ01). For pion production see (1988BU16).

See also (1985MA68, 1985PE1C, 1985WE1D, 1986BO1M, 1986ZH1F, 1987NEZY, 1988WE06), (1985FIZW, 1985HO1J, 1986HAYU), (1986KE1H, 1988AN1F; applications) and (1983KO44, 1983SH1P, 1985AU1C, 1985BE59, 1985DI1B, 1985GU1D, 1985TI08, 1986AL1L, 1986IS1F, 1986LI16, 1986SH35, 1987KO1N, 1987WI16; theor.).

37. ¹²C(p, p)¹²C

Angular distributions of elastically and inelastically scattered protons have been measured at many energies up to E_p = 1040 MeV: see 12.17 (in PDF or PS) here and (1968AJ02, 1975AJ02, 1980AJ01, 1985AJ01).

12.18 (in PDF or PS) displays the information on excited states of ¹²C. A summary of the decay of some excited states is shown in 12.7 (in PDF or PS). The angular distributions have been analyzed by DWBA (and CCBA), DWIA, (including microscopic calculations) and DWTA (DW t-matrix approximation with density-dependent interactions). Microscopic DWIA calculations give good results for transitions which take place through the S = T = 1 part of the effective interaction and also gives a reasonable description of the S = T = 0 transition. However the mechanism for the excitation of ¹²C*(12.71) (S = 1, T = 0) remains a puzzle. At E_p = 402 MeV the differential cross sections for ¹²C*(12.7, 15.1) (J^π = 1⁺) are very similar for large q. This may be due to the smallness of precursor effects [precursor to a pion condensate] (1981ES04).

The spin-flip probability (SFP) for the transition to ¹²C*(4.4) has been measured for E_p = 15.9 to 41.1 MeV: two bumps appear at ≈ 20 and ≈ 29 MeV. It is suggested that the lower one is due to a substructure of the E1 giant dipole resonance while the upper one results from the E2 giant quadrupole resonance. The SFP has also been studied at E_{pol. p} = 24.1, 26.2, 28.7 MeV (to ¹²C*(4.44)), at E_p = 42 MeV (to ¹²C*(12.7)), at E_{pol. p} = 397 MeV (to ¹²C*(9.6, 12.7, 15.1, 16.1)) [the SFP to ¹²C*(9.6) is consistent with zero; the others exhibit large SFP at forward angles] and at E_p = 398, 597 and 698 MeV (to ¹²C*(18.3, 19.4)). See also (1987GRZY; prelim.).

(1980HO07) have measured the angular distribution of γ-rays from the decay of ¹²C*(12.7, 15.1) at E_p = 21.5 to 27 MeV. Microscopic DW calculations were performed for the A₀ and a₂ coefficients from these and earlier data. The theoretical calculations underestimate A₀ for energies below 35 MeV and are in agreement with the experimental A₀ for higher energies. The calculations also predict significant difference in the a₂ values for the transitions from ¹²C*(12.7, 15.1), and these are observed (1980HO07).

(pγ_15.1) angular correlations have been studied at E_p = 400 MeV by (1988HI12): the data are best described by a relativistic model of p-nucleus scattering in the impulse approximation. See also (1986SH1X). A search for a short-lived neutral particle emitted in the decay of ¹²C*(15.1) is reported by (1988DA01) [see for upper limits].

For polarization and yield measurements see ¹³N in (1986AJ01, 1991AJ01) and (1988FE09, 1989CH08). For other ¹²C + p interactions see reaction 39, here. For other work and for earlier references see reaction 40 in (1985AJ01).

38. ¹²C(p-bar, p-bar) ¹²C

Antiproton scattering angular distributions have been measured at E(p-bar) = 46.7 and 179.7 MeV (1986LE13, 1984GA32; to ¹²C*(0, 4.4, 9.6)). See also (1985JA1J; also at 30 MeV; Ph.D. thesis). ¹²C*(7.7) and some other, unresolved, groups were also populated (1986LE13). Cross section measurements are also reported at 1.45 and 1.8 GeV/c (1984AF1A). The knockout (p-bar, p) reaction has been studied at E(p-bar) = 180 MeV (1985GA02) and 600 MeV/c (1987AS06): there is no evidence for narrow bound or resonant overline p-nucleus states. For a polarization study see (1988MA48). For spectra of ³He and α-particles see (1988MA44). See (1985AJ01) for the earlier work, the "General" section here and (1984DA20, 1985AM01, 1985DA24, 1985LI16, 1986KL01, 1987AD04, 1988IN01; theor.).

39. (a) ¹²C(p, 2p)¹¹B Q_m = -15.9572
(b) ¹²C(p, pn)¹¹C Q_m = -18.722
(c) ¹²C(p, pd)¹⁰B Q_m = -25.1868
(d) ¹²C(p, pα)⁸Be Q_m = -7.3666
(e) ¹²C(p, 3p)¹⁰Be Q_m = -27.1852

Recent work on reaction (a) has involved the distribution of protons [and of deuterons from reaction (c)] associated with backward energetic protons over a wide kinematical range (1985MI09; E_p = 800 MeV). Spectra from coincident proton emission from the continuum have been studied at E_p = 200 MeV by (1988CO02). At E_p = 156 MeV states at 18.4, 19.4, 20.6 and ≈ 22 MeV appear to be involved (1989TEZZ; prelim.). At 2.1 GeV (1984TR09) have searched for interactions between the incident protons and a fast dinucleon constituent inside C. For inclusive proton spectra see (1985SE15, 1988FO06). See also (1985HAZW, 500 MeV; prelim.). For reaction (a) see also ¹¹B and (1984VD01, 1985BE30, 1985DO16). For reaction (b) see ¹¹C and (1985BE30, 1985DO16).

For reaction (c) [and for the (p, p³He) reaction] see (1985DE17, 1984DE1F). See also (1984TR09). At E_p = 56.5 MeV reaction (d) proceeds primarily by sequential α-decay. ¹²C*(22.2 ± 0.5, 26.3 ± 0.5) which subsequently decay to ⁸Be_g.s. must therefore have natural parity and a significaant T = 0 admixture. ¹²C*(19.7, 21.1, 26.3) decay to ⁸Be*(2.9). These states must also have a T = 0 component. It is suggested that ¹²C*(21.1) has unnatural parity. At E_p = 44.2 MeV ¹²C*(12.7, 14.1, 21.6, 26.6) are observed in the angular correlation involving α₀ and ¹²C*(21.6, 24.1, 26.6) decay via α₁ to ⁹Be*(2.9) [suggesting 2⁺ for these states, assuming that only resolved states are involved].

For reaction (e) see (1984NA17). A search for a bound ppπ⁺ state is reported at E_p = 500 MeV by (1988FR1D, 1988FR1J; prelim.). For isobar production at 3.88 GeV/c see (1987NA11). For inclusive pion production at E_p = 330, 400, and 500 MeV see (1985DI01). See also (1988AB05). For K⁺ production see (1986AB07, 1988KO36). For η production see (1987BL1L). For other work at high energies see (1986AG1C, 1986CH2H, 1987AG04, 1987AL1J, 1987CH1K, 1987DE1L).

For the earlier work see (1985AJ01). See also the "General" section here, (1986VO17, 1987AR1M, 1988AG1A, 1988BE2B, 1988CHZV), (1985KI1A, 1986BA2D, 1986CH1J, 1987VD1A, 1988LE1I, 1988MO1H, 1988NA1H) and (1983KA1A, 1984GU14, 1985BU04, 1985GA1A, 1985GA1B, 1985KO2C, 1985SM1D, 1986ER1A, 1986GO1U, 1986HO10, 1986OS08, 1986VD01, 1986ZH03, 1987HO1G, 1987HO08, 1987VD1B, 1988BA83, 1988DZ1A, 1988KU16, 1988VD1B, 1989TA03; theor.).

40. (a) ¹²C(d, d)¹²C
(b) ¹²C(d, pn)¹²C Q_m = -2.22459
(c) ¹²C(d, dα)⁸Be Q_m = -7.3666
(d) ¹²C(d, 2p)¹²B Q_m = -14.8117

The angular distribution of elastically and inelastically scattered deuterons has been studied at many energies: see (1968AJ02) and 12.22 (in PDF or PS) in (1975AJ02), 12.17 (in PDF or PS) in (1980AJ01), 12.17 (in PDF or PS) in (1985AJ01) and 12.17 (in PDF or PS) here. In addition to well-known states in ¹²C such as ¹²C*(4.4) [E_x = 4440.5 ± 1.1 keV] and ¹²C*(12.7, 15.1) [see 12.10 (in PDF or PS) for charge-dependent matrix element], the population of ¹²C*((10.8 ± 0.2), (11.8 ± 0.2), 18.3 ± 0.3, 20.6 ± 0.3, 21.9 ± 0.3 (broad), ≈ 27 (broad)) is also reported. See (1980AJ01) for references and for additonal structures which have not been published. Calculated deformation parameters listed in (1980AJ01) are β₂ = -0.48 ± 0.02 and 0.47 ± 0.05, and β₃ = 0.35 ± 0.06.

Reaction (b) has been studied at E_d = 5.0 to 9.85 MeV and at 56 MeV: see (1980AJ01, 1985AJ01). The breakup of deuterons on C has been investigated at 2.1 GeV (1989PU01). For reaction (c) see ⁸Be in (1984AJ01). Energy spectra for the (d, 2p) reaction, with the two protons in the singlet (¹S₀) state, have been studied at E_{pol. d} = 650 MeV and 2 GeV [reaction (d)]: the reaction appears to proceed via a one-step process and therefore can be used to study isospin-spin excitations. The Δ-excitation is observed (1987EL08). For work at very high energies see (1987AG04, 1987AL1J, 1987AR1M, 1987AZ1C, 1988AG1A, 1988SI1B). For high-energy γ-production see (1988TA22). See also ¹⁴N in (1986AJ01, 1991AJ01), (1986JA14) and (1984YA01, 1985GA1A, 1985GA1B, 1986IS1F, 1986KA1B, 1987AU1F, 1987SI10, 1988SI04, 1989TU1A; theor.).

41. ¹²C(t, t)¹²C

Angular distributions of elastically scattered tritons have been determined at E_t = 1.0 to 20.0 MeV [see (1975AJ02) and 12.17 (in PDF or PS) in (1985AJ01)] and at 33 and 36 MeV (see 12.17 (in PDF or PS)). See also (1985SA31; theor.).

42. (a) ¹²C(³He, ³He)¹²C
(b) ¹²C(³He, pd)¹²C Q_m = -5.49354
(c) ¹²C(³He, 2p)¹³C Q_m = -2.77178

Angular distributions of ³He ions have been measured for E(³He) = 2 to 217 MeV: see (1968AJ02, 1975AJ02, 1980AJ01, 1985AJ01) and 12.17 (in PDF or PS) here. Parameters of observed ³He groups are displayed in 12.19 (in PDF or PS).

Angular distributions of the ³He groups to ¹²C*(15.11, 16.11, 16.57, 19.55) have been compared with those for the tritons to ¹²N*(0, 0.96, 1.19, 4.25) in the analog (³He, t) reaction: the correspondence is excellent and suggests strongly that these areT = 1 isobaric analog states. See also 12.12 (in PDF or PS) in (1980AJ01) and 12.19 (in PDF or PS) here. ¹²C*(4.4, 15.2, 18.4, 18.9, 21.3, 23.5, 25.9, 28.8) all appear to correspond to E2 transitions: their strengths add up to 46% of the EWSR (energy-weighted sum rule). See (1980AJ01) for references and (1985AJ01) for additional comments.

For reaction (b) see (1985AJ01). Inclusive proton and deuteron spectra have been studied at E(³He) = 52 MeV by (1984AA01). For reaction (c) see ¹³C and ¹⁵O in (1991AJ01) and (1986KA44). For π^± production see (1986MI25). See also ¹⁵O in (1986AJ01, 1991AJ01), (1987AD1C), (1987MA2D) and (1985GO19, 1985KH08, 1985SH1A, 1986EV01, 1986EV02, 1986IS1F, 1986KA1B, 1986ZE04, 1987RA36, 1987TR01; theor.).

43. (a) ¹²C(α, α)¹²C
(b) ¹²C(α, 2α)⁸Be Q_m = -7.3666

Angular distributions have been measured at many energies up to 1.37 GeV: see 12.24 (in PDF or PS) in (1968AJ02), 12.22 (in PDF or PS) in (1975AJ02), 12.17 (in PDF or PS) in (1980AJ01), 12.17 (in PDF or PS) in (1985AJ01) and 12.17 (in PDF or PS) here. Parameters of observed states of ¹²C are displayed in 12.19 (in PDF or PS). The quadrupole deformation parameter β₂ = -0.30 ± 0.02 [see (1980AJ01)], -0.40 ± 0.02 (1983YA01), while β₃ ≈ 0.23 [see (1980AJ01)] and β₄ = +0.16 ± 0.03 (1983YA01; see also for a review of deformation parameters). In the region of the GDR prominent gross structure is observed consisting of two ≈ 2 MeV wide peaks at 26.2 and 29.2 MeV (1987KI16; see also for a discussion of deformation parameters).

Angular correlation measurements (α₁, γ_4.4) have been carried out for E_α = 10.2 to 104 MeV [see (1980AJ01, 1985AJ01)] and at 25 to 30 MeV (1984TE01, 1986GU06, 1986ZE1C; see for a study of the spin tensors for ¹²C*(4.4)). Reaction (b) has been studied for E_α up to 700 MeV [see (1975AJ02, 1985AJ01)], at 27.2 MeV (1986KO1B; prelim.) and at 31.2 MeV (1986XI1A). For cross sections see ¹⁶O in (1986AJ04) and (1987BU27). For other comments on these two reactions see (1985AJ01). For π^± emission see (1986ALZL, 1986ALZK, 1987AL1G; prelim.). For high-energy γ-production see (1988TA22). For work at very high energies see (1984AN1H, 1985AB1A, 1986BA3D, 1987AG04, 1987AL1J, 1987AR1M, 1988AG1A, 1988SI1B).

44. (a) ¹²C(⁶Li, ⁶Li)¹²C
(b) ¹²C(⁶Li, αd) ¹²C Q_m = -1.4750
(c) ¹²C(⁷Li, ⁷Li)¹²C
(d) ¹²C(⁷Be, ⁷Be)¹²C

Angular distributions in reactions (a) and (c) have been studied at E(⁶Li) = 4.5 to 210 MeV and E(⁷Li) = 4.5 to 131.8 MeV: see (1975AJ02, 1980AJ01, 1985AJ01) for the earlier work and 12.20 (in PDF or PS) here. See also (1989TRZZ). Reaction (b) takes place via ¹²C*(0, 4.4, 7.7): see (1985AJ01, 1986AJ04) and (1985CU04). See also (1988AR22). For VAP measurements (reaction (a)) see (1989VA04; g.s., 4.4) and (1987TA21; g.s.). See also (1988TA08, 1989TRZZ) and ¹⁸F in (1987AJ02).

A search by (1987EY01) for the distribution of the E0 strength determines 10%, (5 ± 1)% and (5 ± 2)% of the EWSR, respectively for ¹²C*(7.7, 10.3) and for 19 < E_x < 21.5 MeV. For fusion and other cross section measurements (reaction (a)) see (1987PA12). For the ⁶Li and ⁷Li + C interaction cross section at 790 MeV/A see (1985TA18). For pion emission see (1984BE35, 1984CH16). The elastic scattering in reaction (d) has been studied at E(⁷Be) = 140 MeV (1989YA02). See also (1986DAZP, 1986SHZP, 1986YOZU), (1984HA53, 1986KA1C, 1986MO1E) and (1983DE48, 1983GO18, 1984MU1D, 1984UH1A, 1985CO21, 1985HE25, 1985KH08, 1985SA13, 1985SH1A, 1986BE45, 1986IO01, 1986KA1B, 1986MI24, 1986SA15, 1986SAZL, 1986SA1D, 1986YO1A, 1987AR13, 1987KA1I, 1987SA21, 1988DEZU, 1988KH08, 1988OT01, 1988SA10, 1988SA15, 1988SE07, 1989KAZY; theor.).

45. ¹²C(⁹Be, ⁹Be) ¹²C

Angular distributions have been obtained at E(⁹Be) = 14 to 158.3 MeV and at E(¹²C) = 12 to 21 and 65 MeV: see 12.20 (in PDF or PS) here and (1980AJ01, 1985AJ01). For fusion and yield measurements see (1985AJ01) and (1985DE22). For the ⁹Be + C interaction cross section at 790 MeV/A see (1985TA18). See also (1988HAZS), (1984FR1A, 1984HA53, 1985BE1A, 1985CU1A) and (1984HA43, 1986BA69, 1986HA13, 1986KA22, 1986MI24, 1988KH08; theor.).

46. (a) ¹²C(¹⁰B, ¹⁰B)¹²C
(b) ¹²C(¹¹B, ¹¹B)¹²C

Angular distributions in reaction (a) have been measured at E(¹⁰B) = 18 and 100 MeV. Those for reaction (b) have been studied at E(¹¹B) = 10.4 to 100.0 MeV and E(¹²C) = 15 to 87 MeV: see (1980AJ01, 1985AJ01) and 12.20 (in PDF or PS) here. For fusion and yield studies see (1985AJ01) and (1985MA10, 1986MA13). See also (1984DEZX, 1984HAZK, 1987SAZW, 1988SAZT). See also (1987PO15), (1984FR1A, 1984HA53, 1985BE1A, 1985CU1A, 1986MA19, 1988MA07), (1982BA1D, 1985BA1T; astrophysics) and (1984HA43, 1984IN03, 1985KO1J, 1986BA69, 1986HA13, 1986RO12, 1988DI08; theor.).

47. (a) ¹²C(¹²C, ¹²C)¹²C
(b) ¹²C(¹²C, α⁸Be)¹²C Q_m = -7.3666

Angular distributions have been measured at E(¹²C) = 10 to 1020 MeV: see (1980AJ01, 1985AJ01) and 12.20 (in PDF or PS) here.

Angular distributions of the magnetic substate population for the single and mutual ¹²C*(4.4) excitation have been measured by (1985SU07) for E(¹²C) = 38 to 110 MeV. The yields of 12.7 and 15.1 MeV γ-rays have been studied at E(¹²C) = 180 MeV (1988HA23), and hard photon collisions have been investigated at E(¹²C) = 576 to 1008 MeV (1986GR19). For other studies of excitation functions and reaction cross sections see (1984KO12, 1984SI15, 1985KO17, 1985KO24, 1985ME1K, 1985PA24, 1986HAZA, 1986HA30, 1986SA29, 1987HO11, 1987KO12, 1988DE18, 1988PA04, 1989LI10, 1989PA05). See also (1984HO1K). For a study of the effects of vacuum polarization in hadron-hadron scattering see (1989VE03). For reaction (b) see (1986SH10, 1988CAZU) and ¹⁶O in (1986AJ04): the excitation of ¹²C*(9.6, 10.8, 14.1) is reported at E(¹²C) = 90 to 140 MeV. For fragmentation studies see (1985HA1U, 1985KR03, 1986EN1D, 1986FO04, 1987FO08, 1988FO03, 1988KI05). See also (1985KR21, 1986LIZP, 1987PO15) and (1989CO1C, 1989HA43; theor.).

For pion production see (1983AN1L, 1984AG1A, 1984BE35, 1984CH16, 1985AR1M, 1986AN40, 1988BA21, 1988NO09). See also (1985OB1A) and the "General" section here. For other studies at very high energies see (1984AD1C, 1984AD1B, 1984AN1H, 1985RO12, 1986AG1B, 1986AN1X, 1986CH2H, 1987AD1E, 1987AG04, 1987AG1A, 1987AL1J, 1987AN20, 1987AR1M, 1988AG1A, 1988SI1B).

48. (a) ¹²C(¹³C, ¹³C)¹²C
(b) ¹²C(¹⁴C, ¹⁴C)¹²C

Angular distributions for reaction (a) have been studied at E(¹²C) = 15 to 87 MeV and E(¹³C) = 12, 36 and 87 MeV [see (1975AJ02, 1985AJ01)] and at E(¹²C) = 94.5 MeV (1986BA80; g.s.) and E(¹³C) = 16.3 to 20.6 MeV (1984FR05; g.s.), 17.3 to 26.5 MeV (1988VO01; g.s.), 36 MeV (1985BY01; ¹²C*(4.4)) and 260 MeV (1985BO39; ¹²C*(0, 4.4)). Elastic angular distributions (reaction (b)) are reported at E(¹²C) = 12 to 20 MeV [see (1980AJ01)] and at E(¹⁴C) = 31.0 to 56 MeV (1985KO04). The spin-flip probability to ¹²C*(4.4) has been studied at E(¹³C) = 36 and 56 MeV by (1985BY01). See (1985AJ01) for the earlier work. For yield and cross section measurements see (1985KO04, 1985RI1C, 1986HA30, 1986STZY, 1987KO12) and (1985AJ01).

49. (a) ¹²C(¹⁴N, ¹⁴N)¹²C
(b) ¹²C(¹⁵N, ¹⁵N)¹²C

Angular distributions (reaction (a)) have been measured at E(¹⁴N) = 21 to 155 MeV [see (1975AJ02, 1980AJ01, 1985AJ01)] and at E(¹⁴N) = 150 MeV (1986GO1H; prelim.). Angular distributions for reaction (b) are reported at E(¹⁵N) = 31.5 to 94 MeV: see (1980AJ01, 1985AJ01). High-energy γ-ray emission has been studied at E(¹⁴N) = 280 to 560 MeV (1986ST07). See also (1987ST1F). For yield, fragmentation and cross-section measurements see (1985AJ01) and (1985CA01, 1986HA1F, 1986MO13, 1987GO01, 1987ST01, 1988KI06). For the ¹²C(¹⁴N, d¹²C)¹²C reaction see (1985ARZW , 1986AR1G; prelim.).

See also ¹⁴N and ¹⁵N in (1991AJ01), (1987VE1D, 1988HAZS), (1984FR1A, 1984HA53, 1985BE1A, 1985CU1A, 1987GE1B, 1989BL1D), (1982BA1D, 1985BA1T; astrophysics) and (1984HA43, 1985HU04, 1985KO1J, 1985VI09, 1986BA62, 1986BA69, 1986HA13, 1986POZW, 1986RE14, 1987BI20, 1987RE03, 1987RE11, 1988BA2X, 1988BA37, 1988HE12, 1988PR02, 1989SH05; theor.).

50. (a) ¹²C(¹⁶O, ¹⁶O)¹²C
(b) ¹²C(¹⁶O, α)¹²C¹²C Q_m = -7.16195

Angular distributions have been measured at E(¹⁶O) = 17.3 to 1503 MeV and at E(¹²C) = 65 to 76.8 MeV: see (1975AJ02, 1980AJ01, 1985AJ01) and 12.20 (in PDF or PS) here. The excitation of ¹²C*(0, 4.4, 14.1, 26) has been reported. The latter is due to the wide (Γ ≈ 4 MeV) giant quadrupole resonance. It contains 25⁺¹⁵_-10% of the E2 strength: see (1985AJ01).

For fusion, yield, cross-section and fragmentation studies see (1985AJ01) and (1984TS07, 1985BE02, 1985BE40, 1985CA01, 1985KA03, 1985MU18, 1986CH27, 1986CH41, 1986GA13, 1986HA30, 1986IK03, 1987SU03, 1988KO17). See also (1984RU1A, 1987NA1C, 1988SZ02, 1989KRZX, 1989WE1E). For work at very high energies see (1987YO1A).

51. (a) ¹²C(¹⁷O, ¹⁷O)¹²C
(b) ¹²C(¹⁸O, ¹⁸O)¹²C

The elastic scattering angular distributions have been studied at E(¹⁷O) = 30.5 to 35 MeV and at E(¹⁸O) = 32.0 to 140 MeV [see (1980AJ01, 1985AJ01)] and at E(¹⁷O) = 40 to 70 MeV (1986FR04). For fusion, yields, and cross-section measurements see (1985BE40, 1985BE37, 1985CA01, 1986FR04, 1986GA13) and (1985AJ01). For the decay of ¹⁸O* into ¹⁴C + α, see reaction 34 in ¹⁸O (1987AJ02). See also (1984FR1A, 1984HA53, 1989CI1C, 1989FR04), and (1986CI01, 1986HA13, 1987AR1E, 1987MO27, 1987VO05, 1988TH02, 1988THZZ; theor.).

52. ¹²C(¹⁹F, ¹⁹F)¹²C

Angular distributions have been measured at E(¹²C) = 30.0, 40.3, 50.0 and 60.1 MeV and at E(¹⁹F) = 40, 60, and 68.8 MeV [see (1980AJ01, 1985AJ01)] as well as at E(¹⁹F) = 29.3 to 34.8 MeV (1984MA32; elastic) and E(¹²C) = 30.0, 40.3, 50.0 and 60.1 MeV (1988TA12; ¹²C*(0, 4.4) and several states in ¹⁹F). The substate population probability for ¹²C*(4.4) has been studied by (1986IKZZ) at E(¹⁹F) = 63.8 MeV. For fusion and yield measurements see (1985AJ01) and (1984MA32, 1986GA13, 1986VO12). For the α-decay of ¹⁹F* see reaction 42 in ¹⁹F in (1987AJ02) and (1985SM04). See also (1986MA1Z), (1984FR1A, 1984HA53) and (1985HU04, 1986HA13, 1986HE1A, 1987CO01, 1988DI08; theor.).

53. (a) ¹²C(²⁰Ne, ²⁰Ne)¹²C
(b) ¹²C(²²Ne, ²²Ne)¹²C

Elastic angular distributions (reaction (a)) have been measured at E(¹²C) = 20 to 77.4 MeV and at E(²⁰Ne) = 65.7 MeV: see (1980AJ01, 1985AJ01). For fusion, reaction cross section, yield and evaporation residue studies see (1985AJ01) and (1984KO12, 1984RA10, 1985MU18, 1985OS05, 1987KO12, 1987SI06). See also (1985FL1B). For pion production see (1985AJ01) and (1983AN1L). For other work at very high energies see (1984AN1H, 1987AN20, 1988DU01).

54. (a) ¹²C(²⁴Mg, ²⁴Mg)¹²C
(b) ¹²C(²⁶Mg, ²⁶Mg)¹²C

Elastic angular distributions have been measured at E(¹²C) = 20 to 60 MeV (reaction (a)) and at E(¹²C) = 20 to 56 MeV (reaction (b)): see (1985AJ01). For fusion, yields and cross-section measurements see (1985AJ01) and (1986GL03, 1988DU11). The fission of ²⁴Mg into 2 ¹²C (involving ¹²C*(0, 4.4)) has been studied by (1986FUZW; prelim.). See also (1982CI1C, 1982ME1A, 1984FR1A, 1984HA53, 1986BE1D, 1987KA2A, 1987LA05, 1988RA1G, 1989CI1C) and (1985AN16, 1985LE25, 1986BO14, 1986HA13, 1987BR1H, 1987GR04, 1988AY03, 1988KU1H; theor.).

55. ¹²C(²⁷Al, ²⁷Al)¹²C

Angular distributions have been measured at E(¹²C) = 30.0 to 39.9 MeV and at 82 MeV: see (1985AJ01). For fusion, yield, and breakup measurements see (1985AJ01) and (1984KO12, 1985HA19, 1987KO12). See also (1987PO15). For work at very high energies see (1986AN1X). See also (1985XI1B, 1986BL1L), (1984FR1A, 1986CA30, 1988SN1A) and (1984FO21, 1984NA27, 1986POZW, 1986RO12, 1987ST1E, 1988TO02, 1989SH05; theor.).

56. (a) ¹²C(²⁸Si, ²⁸Si)¹²C
(b) ¹²C(²⁹Si, ²⁹Si)¹²C
(c) ¹²C(³⁰Si, ³⁰Si)¹²C

Elastic angular distributions have been studied for reaction (a) at E(¹²C) = 19 to 186.4 MeV and at E(²⁸Si) = 58.3 to 116.7 MeV [see (1980AJ01, 1985AJ01)] as well as at E(¹²C) = 56, 59, 66 and 69.5 MeV (1985SH1K) and 65 MeV (1988YA06).

Alpha-γ angular correlations have been studied at E(²⁸Si) = 112.3 and 142.7 MeV: ¹²C*(4.4) is found to be produced almost entirely in the m= 0 magnetic substate (1986RA08). For fusion, yield and breakup measurements see (1985AJ01) and (1984SH19, 1986HA33, 1987ZH1G). See also (1985SAZZ, 1986FEZY, 1986HAZS, 1987SHZY, 1988MAZZ). For pion production see (1983AN1L). For other work at very high energies see (1987AN20).

57. ¹²C(³²S, ³²S)¹²C

Elastic angular distributions are reported at E(¹²C) = 35.8 MeV and E(³²S) = 73.3 to 160 MeV [see (1980AJ01, 1985AJ01)] as well as E(³²S) = 194, 239 and 278 MeV (1987HI10). For fusion, yield and evaporation residue studies see (1985AJ01) and (1985KO21, 1986PL02, 1987HI10, 1988AR21). See also (1987LA05) and (1989CI1C).

58. (a) ¹²C(³⁹K, ³⁹K)¹²C
(b) ¹²C(⁴⁰Ar, ⁴⁰Ar)¹²C

Elastic angular distributions (reaction (a)) have been studied at E(¹²C) = 54 and 63 MeV: see (1985AJ01). For reaction (b) see (1989PL02) and (1985MO1K; prelim.).

59. (a) ¹²C(⁴⁰Ca, ⁴⁰Ca)¹²C
(b) ¹²C(⁴²Ca, ⁴²Ca)¹²C
(c) ¹²C(⁴⁸Ca, ⁴⁸Ca)¹²C

The elastic scattering in all three reactions has been studied at E(¹²C) = 51.0, 49.9 and 49.9 MeV, respectively [see (1985AJ01)] and, for reaction (a), at E(¹²C) = 180, 300 and 420 MeV (1986SA29). For fusion, yield, cross-section and fragmentation studies see (1980AJ01, 1985AJ01) and (1984GR20, 1984KO12, 1986SA29, 1987KO12). See also (1985XI1B), (1989BE17, 1989GR04) and (1984SH1T, 1985BL18, 1986CH20, 1986CH38; theor.).

60. ¹²N(β⁺)¹²C Q_m = 17.338

The decay is mainly to the ground state via an allowed transition. Branching ratios to other states of ¹²C are displayed in 12.21 (in PDF or PS). The half-life of ¹²N is 11.000 ± 0.016 ms (1978AL01). See also (1968AJ02). The ratio of the branching ratios ¹²N/¹²B for the decays to ¹²C*(4.4) is 1.528 ± 0.027 (1988NA09). See also (1985AJ01). This leads to the following values for the mirror asymmetries of ¹²B and ¹²N for decay to ¹²C*(0, 4.4): δ_g.s. = +0.129 ± 0.008 (1978AL01), δ_4.4 = +0.066 ± 0.018 (1988NA09). See also (1989KR1C).

61. ¹³C(γ, n) ¹²C Q_m = -4.9463

The decay of the giant resonance in ¹³C takes place predominantly to ¹²C*(15.1, 16.1) [and to their analogs in ¹²B]. Below E_γ = 21 MeV transitions to ¹²C*(4.4) are dominant: see (1980AJ01). See also ¹³C in (1991AJ01).

62. (a) ¹³C(π⁺, p)¹²C Q_m = 135.405
(b) ¹³C(π⁺, π⁰p)¹²C Q_m = 0.440

Angular distributions (reaction (a)) have been measured at E_π⁺ = 90 to 170 MeV to ¹²C*(0, 4.4, 7.7, 9.6, 12.7, 14.1, 15.1, 16.1, 19.1, 20.6, 22.9, 25.3): an energy dependent ratio for the excitation of ¹²C*(12.7, 15.1) is reported. Similarities in the population of states seen in this reaction and in the (p, d) reaction are observed. Angular distributions at E_π⁺ = 32 MeV are also reported: see (1985AJ01). For reaction (b) see (1988POZV).

63. ¹³C(p, d)¹²C Q_m = -2.7218

Angular distributions have been measured at E_p = 8 to 800 MeV [see (1980AJ01, 1985AJ01)], at E_p = 18.6 MeV (1986GO23, 1987GO27; ¹²C*(0, 4.4)), 41.5 MeV (1987CA20; ¹²C*(0, 4.4, 12.7, 15.1, 16.1)) and 800 MeV (1984SM04; ¹²C*(0, 4.4, 12.7, 14.1, 15.1, 16.1)) and at E_pol.
p = 119 MeV (1987LE24; ¹²C*(0, 4.4, 7.7, 9.6, 12.7, 14.1, 15.1, 16.1, 16.6, 17.8, 18.16 ± 0.07, 18.8, 19.9, 20.3, 20.6)) and 500 MeV (1984OH06; g.s.). The population of ¹²C*(10.3, 15.4) is also reported, and the Γ_c.m. of the structures at E_x = 18.2, 18.8, 19.9, 20.3 and 20.6 MeV are, respectively, 240 ± 50, 120 ± 30, ≈ 400, ≈ 220 and ≈ 210 keV (1987LE24). (1984SM04) report structures at 20.61 ± 0.04 and 25.4 ± 0.1 MeV, the latter with Γ ≥ 0.5 MeV. The earlier work [see (1980AJ01)] indicated states at 17.76 ± 0.02 [80 ± 20], 18.80 ± 0.04 [80 ± 30], 21.5 ± 0.2 [< 200] and 22.55 ± 0.05 [< 200] MeV [the numbers shown in brackets are Γ_c.m., in keV].

For (d, γ) correlations via ¹²C*(15.1) see (1987CA20). See also ¹⁴N in (1991AJ01), (1987GIZZ, 1988LE08) and (1988BE1I, 1988GUZW; theor.).

64. ¹³C(d, t)¹²C Q_m = 1.3109

Angular distributions have been studied at E_d = 0.41 to 27.5 MeV [see (1975AJ02, 1980AJ01)] and 18 MeV (1988GO02, 1988GU20; t₀, t₁) as well as E_{pol. d} = 29 MeV [to ¹²C*(0, 4.4, 12.7, 15.1, 16.1)]: see (1985AJ01). For charge-dependent matrix elements between ¹²C*(12.7, 15.1) see 12.10 (in PDF or PS). See also (1986GU1J; applications) and (1988GUZW; theor.).

65. (a) ¹³C(³He, α)¹²C Q_m = 15.6314
(b) ¹³C(³He, 2α)⁸Be Q_m = 8.2648

Angular distributions have been measured at many energies up to E(³He) = 45 MeV [see (1980AJ01, 1985AJ01)] and at 22.7 MeV (1987VA1I; α₀, α₁; prelim.). See (1984VA39, 1985VA1E, 1986ZE1C) for a study of the spin tensors for ¹²C*(4.4).

A study of reaction (b) leads to Γ_α/Γ for ¹²C*(15.11) = (4.1 ± 0.9)%; together with the other parameters for the decay of the state (see 12.7 (in PDF or PS)) this leads to Γ_α = 1.8 ± 0.3 eV. If this isospin-forbidden α-width is the result of mixing between ¹²C*(12.71, 15.11) via a charge-dependent interaction the matrix element is 340 ± 60 keV: see, however, 12.10 (in PDF or PS) here, and (1980AJ01). See also (1987BA2B, 1987ZE02, 1988GOZB; theor.) and ¹⁶O in (1986AJ04).

66. ¹³C(α, αn)¹²C Q_m = -4.9463

See ¹³C in (1991AJ01) and (1984DE44, 1985DE1Q).

67. (a) ¹³C(⁶Li, ⁷Li)¹²C Q_m = 2.3037
(b) ¹³C(⁷Li, ⁸Li)¹²C Q_m = -2.9136

At E(⁷Li) = 34 MeV angular distributions have been observed for the reactions to ¹²C*(0, 4.4) + ⁷Li*(g.s., 0.48) and ⁸Li*(0, 0.95) in all combinations. While ¹²C*(0, 4.4) are dominant in the two spectra, ¹²C*(7.7, 9.6) and, in reaction (a) at E(⁶Li) = 36 MeV, ¹²C*(12.7), are also populated: see (1980AJ01) and (1987CO16; reaction (b)).

68. (a) ¹³C(¹³C, ¹⁴C)¹²C Q_m = 3.2302
(b) ¹³C(¹⁴C, ¹⁵C)¹²C Q_m = -3.7283
(c) ¹³C(¹⁶O, ¹⁷O)¹²C Q_m = -0.8029

Angular distributions have been reported for reaction (a) at E(¹³C) = 16.0 to 50.0 MeV : (see (1985AJ01) [also excitation functions]) and at E(¹³C) = 20.0 to 27.5 MeV (1988BI11) for reaction (b). See also (1984BA31) and (1987TH04; theor.). For reaction (c) see (1989FR04). See also (1980AJ01).

69. ¹⁴C(γ, 2n)¹²C Q_m = -13.1229

See ¹⁴C in (1991AJ01), (1985PY01) and (1987GO09; theor.).

70. ¹⁴C(p, t)¹²C Q_m = -4.6410

Angular distributions have been measured at E_p = 14.5, 18.5, and 39.8 MeV: see (1975AJ02). At E_p = 54 MeV angular distributions are reported to two states at E_x = 27.57 ± 0.03 and 29.63 ± 0.05 MeV [Γ_c.m. ≲ 200 keV]: their identification as the first T = 2 states is supported by the similar angular distributions to the first two T = 2 states in ¹²B, reached in the (p, ³He) reaction [see reaction 28 in ¹²B]. The lower T = 2 state is well fitted by L = 0; the angular distribution to ¹²C*(29.63) is rather featureless. It is suggested that its shape is somewhat more consistent with L = 0 than with L = 2 (1976AS01): [(1976BA24) has suggested that the second T = 2 state in A = 12 may have J^π = 0⁺.] It is not excluded that the group to ¹²C*(29.63) may be due to unresolved states (1976AS01). (1976AS01) report Γ_p/Γ ≈ 0.3 ± 0.1 and Γ_α₁/Γ < 0.1 for the first T = 2 state and Γ_p/Γ = 0.8 ± 0.2, Γ_p₀/Γ ≈ 0.4 and Γ_α/Γ ≈ 0.2 for ¹²C*(29.63). (1978RO08) report E_x = 27595.0 ± 2.4 keV, Γ ≤ 30 keV for the first T = 2 state and calculate the decay properties for two values of the total width, 0 and 30 keV. Branching ratios for the decays to ⁸Be(0) + α; ¹¹B*(0, 2.12, 4.45, 5.02, 6.74 + 6.79) + p; and ¹⁰B(0) + d are, repectively, (10.5 ± 3.0)%; (3.0 ± 2.2)%, (8.0 ± 2.3)%, (0 ± 3.3)%, (8.4 ± 3.2)%, (8 ± 5)%; and (2.8 ± 2.0)% (1979FR04).

71. (a) ¹⁴N(p, ³He)¹²C Q_m = -4.7789
(b) ¹⁴N(p, pd)¹²C Q_m = -10.2724

Angular distributions (reaction (a)) have been studied at E_p = 7.5 to 52 MeV [at the higher energies to ¹²C*(12.7, 14.1, 15.1, 16.1)] as well as to ¹²C*(0, 4.4): see (1980AJ01). For reaction (b) see (1985DE17) and (1986VDZY). See also (1987VD03, 1987VD1A) and (1986GO28; theor.).

72. ¹⁴N(d, α)¹²C Q_m = 13.5743

Observed α-particle groups are displayed in 12.19 (in PDF or PS). Angular distributions have been measured at energies up to 40 MeV: see (1980AJ01) [also for J^π assignments]. See also (1987SI1D; applications), (1983US01; theor.) and ¹⁶O in (1986AJ04).

73. ¹⁴N(α, ⁶Li)¹²C Q_m = -8.7974

See (1988SH1E; theor.).

74. ¹⁴N(⁷Li, ⁹Be)¹²C Q_m = 6.4233

See (1986GO1B).

75. ¹⁴N(¹²C, d)¹²C¹²C Q_m = -10.2724

See (1987AR25) and ¹⁴N in (1991AJ01).

76. ¹⁵N(p, α)¹²C Q_m = 4.9656

Angular distributions of α₀ and α₁ have been measured for E_p up to 43.7 MeV. At the highest energy the angular distributions to the 0⁺ states ¹²C*(0, 7.7, 17.8) are fitted by L = 1. The distributions to ¹²C*(14.1, 16.1) [J^π = 4⁺, 2⁺] are consistent with L = 3; see (1980AJ01). For work on cross sections and resonances see ¹⁶O in (1986AJ04) and (1988HO1F). See also (1987WE1C, 1988CA26; astrophysics) and (1984BE1A, 1984HA1Q, 1986LE1L, 1986RO18, 1988GN1A; applications).

77. ¹⁵N(α, ⁷Li)¹²C Q_m = -12.3806

At E_α = 42 MeV angular distributions involving ¹²C*(0, 4.4) and ⁷Li*(0, 0.48) have been obtained: see (1980AJ01). See also (1988SH1E; theor.).

78. (a) ¹⁶O(γ, α)¹²C Q_m = -7.1619
(b) ¹⁶O(e, e'α)¹²C Q_m = -7.1619

For reaction (a) see (1986BA50; astrophysics) and (1984GL11, 1987BU1A; theor. [γ, 2d]). For reaction (b) see (1987HO1E). See also ¹⁶O in (1986AJ04) and (1988BU06; theor.).

79. ¹⁶O(p, pα)¹²C Q_m = -7.1619

This reaction proceeds primarily to ¹²C*(0, 4.4) at E_p = 101.5 MeV (1984CA09): ¹²C(14.1) is also populated. The breakup into 4α has been studied by (1986VD04). See also (1985AJ01), (1987LA11, 1988LE08, 1988MU1G; astrophysics) and (1985VD03, 1987VD1A) and (1986GO28; theor.).

80. ¹⁶O(d, ⁶Li)¹²C Q_m = -5.6869

Angular distributions have been measured at E_d = 12.7 to 80 MeV [see (1980AJ01, 1985AJ01)], at 54.2 MeV (1984UM04; ¹²C*(0, 4.4, 7.7, 9.6, 14.1)) [see also for spectroscopic factors] and at E_{pol. d} = 18 and 22 MeV (1987TA07; ¹²C*(0, 4.4)) and 51.7 MeV (1986YA12; ¹²C*(0, 4.4, 14.1)). For polarization measurements see ¹⁸F in (1987AJ02).

81. ¹⁶O(³He, ⁷Be)¹²C Q_m = -5.5746

Angular distributions have been studied at E(³He) = 30, 41 and 70 MeV: see (1980AJ01, 1985AJ01). ¹²C*(0, 4.4, 7.7, 9.6) are populated. See also (1986BA89; astrophysics) and (1987RA37; theor.).

82. (a) ¹⁶O(α, 2α)¹²C Q_m = -7.1619
(b) ¹⁶O(α, ⁸Be)¹²C Q_m = -7.2538

At E_α = 90 MeV angular distributions involving ¹²C*(0, 4.4) (reaction (a)) have been analyzed by PWIA and DWBA: S_α = 2.9 ± 0.5 and 0.70 ± 0.23, respectively. At E_α = 65 MeV angular distributions involving ⁸Be_g.s. (reaction (b)) and ¹²C*(0, 4.4, 7.7, 9.6, 14.1) have been measured [the ground state distributions have also been studied for E_α = 55 to 72.5 MeV]: S_α = 0.25, 1.07, 0.05, 1.40 for ¹²C*(0, 4.4, 7.7, 14.1): see (1980AJ01) for references.

83. (a) ¹⁶O(⁹Be, ¹³C)¹²C Q_m = 3.4856
(b) ¹⁶O(¹⁶O, ²⁰Ne)¹²C Q_m = -2.4263

For reaction (a) see (1988WE17) and ¹³C in (1991AJ01). For reaction (b) see (1986CA24) and ²⁰Ne in (1987AJ02). See also (1988AU03), (1984ME10, 1989VO1D) and (1984AP03, 1984KO13, 1987GA1L, 1988GA19, 1988GA1L; theor.).

84. ¹⁹F(d, ⁹Be)¹²C Q_m = 0.2662

Angular distributions have been obtained at E_d = 9 to 14.5 MeV: see (1980AJ01, 1985AJ01). ¹²C*(0, 4.4) are populated.

85. ²⁰Ne(α, ¹²C)¹²C Q_m = -4.6229

Angular distributions have been measured in the range E_α = 13.4 to 20.8 MeV: see (1985AJ01). See also (1985ST1B) and (1988SH1F; theor.).

86. ²³Na(p, ¹²C)¹²C Q_m = -2.2433

Angular distributions involving ¹²C_g.s. have been studied at E_p = 7.9 to 18.6 MeV (1987KI26).

87. ²³Na(d, ¹³C)¹²C Q_m = 0.4785

See (1986GO26; E_d = 13.6 MeV).

88. ²⁴Mg(p, p¹²C)¹²C Q_m = -13.9335

The fission of ²⁴Mg has been studied at E_p = 190 MeV (1987DA01).

89. ²⁴Mg(α, ¹⁶O)¹²C Q_m = -6.7716

Angular distributions have been reported at E_α = 22.8 to 25.4 MeV and at 90 MeV [see (1980AJ01)], at 25.13 to 27.76 MeV (1986SK01) and at 27.8 to 29.4 MeV (1989ES06). See also (1987SH1B) and (1988SH1F; theor.).

90. ²⁴Mg(¹²C, ¹²C)¹²C¹²C Q_m = -13.9335

The fission of ²⁴Mg has been studied at E(²⁴Mg) = 357 MeV (1986WI14).