12C 12B B- DECAY:20.20 MS 1981Ka31,2009Hy01,2016Mu0618NPA 201808
12C H TYP=FUL$AUT=J.H. KELLEY, J.E. Purcell and C.G. SHEU$
12C 2 H CIT=NP A968, 71 (2017)$CUT=1-Jan-2017$
12C c 1972Al31: {+12}B(|b{+-}), measured |b|g-coin. Deduced log| {Ift},
12C xc |b-branching.
12C c 1974Mc11: {+12}B, measured E{-|b}, I{-|b}, |b|g-coin. Deduced log|
12C xc {Ift}.
12C c 1978Al01: {+12}B(|b{+-}), measured E{-|b}, I{-|b}, |b|g-coin, T{-1/2}.
12C 2c Deduced |b-branching, mirror asymmetries, {Ift}.
12C c 1981Ka31: {+12}B(|b{+-}), measured |b|g-coin, |b|g(t). Deduced I{-|b},
12C xc log| {Ift}.
12C c 1988Na09: {+12}B, measured I{-|b}, I{-|g}, |b|g-coin. Deduced mirror
12C 2c asymmetry. Deduced Gamow-Teller |b-decay branching ratio.
12C c 1988Sa04: {+12}B(|b{+-}), measured |b-decay T{-1/2}.
12C c 1990Ca10: {+12}B(|b{+-}), measured spectral shape factors.
12C c 1993Mi36, 1993Oh05: {+12}B(|b{+-}), measured modified |b-NMR spectra.
12C 2c Deduced quadrupole moment.
12C c 2000St19: {+12}B(|b{+-}), measured E{-|b}, I{-|b}.
12C c 2005Di16: {+12}B(|b{+-}), measured |b-delayed E{-|a}, |a|a-coin.
12C 2c {+12}C deduced excited states, J, |p. R-matrix analysis.
12C c 2007PeZY: {+12}B(|b{+-}), measured branching |b-decay ratios.
12C c 2009Di06: {+12}B(|b{+-}), measured E{-|a}, E{-|g}, |a|a|a-coin. {+12}C
12C 2c deduced levels, J, |p, triple-|a continuum states and their decay
12C xc modes.
12C c 2009Hy01: {+12}B(|b{+-}), deduced branching ratio, log| {Ift}, |b(GT)
12C 2c to various {+12}C states.
12C c 2009Hy02: {+12}B(|b{+-}), measured E{-|a}, I{-|a}, E{-|g}, I{-|g},
12C 2c E{-|b}, |b|g-, |b|a-, |a|a|a-coin. {+12}C deduced levels, |b feedings,
12C 3c and log| {Ift}. Triple-|a method and R-matrix analysis.
12C c 2010Hy01: {+12}B(|b{+-}), measured 3|a summed spectra and associated
12C 2c branching ratios for breakup via the {+8}Be ground-state and via
12C 3c excited states of {+8}Be. {+12}C deduced levels, resonances,
12C 4c Gammow-Teller strengths and widths using multilevel, many-channel
12C xc R-matrix formalism.
12C c 2009Hy01,2009Hy02,2010Hy01: The authors performed two measurements
12C 2c of {+12}B decay into |a unbound states of {+12}C using two different
12C 3c techniques. In addition {+12}N decay was also measured.
12C 4c The first method involved implantation of {+12}B into a thin carbon
12C 5c foil located in the center of a large solid angle
12C 6c Si Strip array (at IGSOL/JYFL)
12C 6c that measured breakup |a particle kinematics;
12C 7c a HPGe detector measured
12C 8c the {+12}C*(4.44 MeV) de-excitation gamma-rays, and the measurement was
12C 9c normalized to the value presently adopted in ENSDF.
12C Ac The second method involved implantation of {+12}B into
12C Bc a thick Si detector (at TRIuP/KVI) and measuring
12C Cc the total 3|a decay energy.
12C c (2009Hy02) gives details of the JYFL measurement, while (2009Hy01)
12C 2c is reported as giving the most precise analysis of the KVI and JYFL
12C 3c measurements.
12C c (2010Hy01) gives a detailed multi-channel multi-level R-matrix
12C 2c analysis of 0+ and 2+ levels above the E{-x}=7.65 MeV level that may
12C 3c contribute to the shape of the 3|a energy spectrum observed in {+12}B
12C 4c and {+12}N decay to {+12}C. The analysis focuses mainly on these
12C 5c higher-lying state and is difficult to fold in with the analysis
12C 6c given in (2009Hy01,2009Hy02). A significant difference from the prior
12C 7c work is the assumption that the E{-x}=10.3 MeV bump (J{+|p}=0+) is
12C 8c from interference; they suggest instead the J{+|p}=0{++}{-3} state at
12C 9c E{-x}=11.2 MeV {I3} with |G=1.5 MeV {I6}.
12C c 2016Mu06: The authors measured the {+12}C |g rays produced following
12C 2c {+12}B |b decay and deduced the branching ratio to {+12}C*(7654).
12C c {+12}B atoms were produced at the center of the Gammasphere detector
12C 2c by irradiating a thick deuterated titanium foil with 40 MeV {+11}B
12C 3c ions from the ANL/ATLAS accelerator. The |g rays emitted following
12C 4c {+12}B decay were detected using the Gammasphere, a 110 element
12C 5c Compton suppressed HPGe detector array; in the present measurement
12C 6c 98 array elements were utilized. Throughout the measurement a low-Z
12C 7c target chamber was used to minimize the bremsstrahlung background
12C 8c caused by the high-energy |b rays emitted in the decays.
12C c The |g singles and |g-|g coincidence spectra were analyzed to
12C 2c determine yield of the J{+|p}=2{++}{-1}|)0{++}{-1} |g rays (4.44 MeV)
12C 3c and J{+|p}=0{++}{-2}|)2{++}{-1} |g rays (3.21 MeV). The |g-ray energies
12C 4c are reported. A total of ~10{+9} |g|g coincidence events are observed.
12C 7c The |g|g angular correlations are analyzed yielding {Ia{-2}}=-3.3 {I7}
12C 8c and {Ia{-4}}=4.2 {I9}.
12C c In the discussion, the branching ratio feeding {+12}C*(7654), B(7.65),
12C 2c is related to the |g(4.44)-|g(3.21) coincidence yield,
12C 3c |G{-|g}/|G(7.65), the B(4.44) and a set of variables that depend on
12C 4c the experimental configuration. The authors used
12C 5c |G{-|g}/|G(7.65)=(4.07 {I11})|*10{+-4} (see discussion) and
12C 6c B(4.44)=(1.23 {I5})%, which is the unweighted average of values given
12C 7c in (1990Aj01).
12C cL E$From recoil corrected |g-ray energies, except where noted.
12C c For other references see (1980Aj01).
12B P 0.0 1+ 20.20 MS 2 13369.4 13
12B cP QP$ From (2017Wa10)
12B cP J,T$From adopted levels for {+12}B in ENSDF database
12C N 1.0 1.0 1.0
12C PN 4
12C cL J,T$From adopted levels
12C L 0 0+
12C B 98.216 28 4.0617 5
12C S B EAV=6438.65 65
12C cB IB Unity minus the sum of branching to higher
12C 2cB states. See discussion (2017Ke05) Table 12.24.
12C L 4439.82 312+ 10.8E-3 EV6
12C B 1.182 19 5.143 7
12C S B EAV=4234.18 67
12C cB IB I|b(4440) is used as a global normalization
12C 2cB in most measurements.
12C cB IB We adopt I|b=1.182 {I19} from (1981Ka31) since the
12C 2cB experimental approach
12C 3cB aimed to overcome most systematic effects that influence the value.
12C 4cB In some other analyses, the unweighted average of
12C 5cB 1.283 {I40} (1978Al01) and 1.182 {I19}
12C 6cB (1981Ka31) was used to normalize the reported values. In (1990Aj01),
12C 7cB both values were listed with no preference or average value given.
12C 8cB The value given of (1981Ka31) is based on their measured value, while
12C 9cB the value in (1978Al01) is a
12C acB weighted average of 1.276 {I50} measured by them and 1.29 {I5}
12C bcB previously adopted by (1974Mc11). See Table 12.23 in (2017Ke05).
12C G 4438.91 311.182 19
12C 2 G FL=0
12C cG E$From (1967Ch19).
12C L 7657.8 100+ 9.3 EV 9
12C cL E Based on the atomic mass of {+4}He
12C 2cL and the decay energy for the breakup of this state into
12C 3cL 3|a, 379.6 keV {I20}: See (1980Aj01)
12C B 0.54 2 4.572 17
12C S B EAV=2642.55 81
12C cB IB The adopted value is dominated by renormalized
12C 2cB (KVI) results reported in
12C 3cB (2009Hy01). See Table 12.24 in (2017Ke05).
12C G 3216.9 8 2.3E-4 1
12C 2 G FL=4439.82
12C cG RI$From |G|g/|G=(4.16 {I11})|*10{+-4} and
12C 2cG I|b(0.54 {I2})%.
12C cG E$From (2016Mu06).
12C L 10.3E+3 (0+) 3.0 MEV 7
12C B 0.062 3 4.287 21
12C S B EAV=1351.93 63
12C cB IB$From weighted average of the renormalized values 0.055 {I7} (JYFL)
12C 2cB and 0.063 {I3} (KVI) in (2009Hy02). See Table 12.24 in (2017Ke05).
12C cB $In (2010Hy01)the authors indicate that the J{+|p}=0{++}{-3}
12C 2cB resonance has parameters E{-x}=11.2 MeV {I3} with |G=1.5 MeV {I6},
12C 3cB suggesting that the previously observed E{-x}=10.3 MeV bump results
12C 4cB from interference. They further indicate that the J{+|p}=2{++}{-2}
12C 5cB resonance has parameters E{-x}=11.1 MeV {I3} and |G=1.4 MeV {I4}. In
12C 6cB addition, for these two states (2010Hy01) find B(>)=0.07 {I3} and
12C 7cB B(>)=0.06 {I4} (log| {Ift}=4.75 {I25} and log| {Ift}=4.82 {I35}) for
12C 8cB the J{+|p}=0{++}{-3} and 2{++}{-2} states, respectively.
12C 9cB See Table 12.24 in (2017Ke05).
12C L 12710 1+ 18.1 EV 28
12C B 0.00026 2 3.91 4
12C S B EAV=243.62 54
12C cB IB$From weighted average of renormalized values
12C 2cB 3.2|*10{+-4} {I7} (JYFL)
12C 2cB and 2.6|*10{+-4} {I2} (KVI) in (2009Hy02).
12C 3cB See Table 12.24 in (2017Ke05).