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The Coulomb dissociation of 27P was studied experimentally using 27P beams at 57MeV/nucleon with a lead target. The E2 gamma decay width of the first excited state in 27P was determined to be (2.8±0.5)×10-5eV. The total ( M1 + E2) gamma decay width of the state, which is of astrophysical interest, is estimated by combining the experimental result and a shell model calculation. The reaction rate of 26Si(p,γ)27P is deduced from the estimated total gamma decay width. The astrophysical implication derived from estimated gamma decay width is discussed. [ABSTRACT FROM AUTHOR]

We measured B( E2;0+g.s. → 2+1) values for the proton-rich 46Cr, 50Fe, and 54Ni nuclides by intermediate-energy Coulomb excitation in order to study the systematic behavior of collectivity in the Z = 20-28 region. The present study completes the B( E2) values for the Tz = ±1 even-even pair nuclei up to Z = 28. The double ratios of proton and neutron matrix elements, (| Mn|/| Mp|)/( N/ Z), have been extracted from the B( E2) values combining with the ones of their mirror nuclei, and compared with theoretical predictions. [ABSTRACT FROM AUTHOR]

We have studied the 2+1 state in neutron-rich 16Cvia inelastic proton scattering in inverse kinematics, using a 33 MeV/nucleon beam. From the angle-integrated cross-section, the deformation parameter βpp’ = 0.50(8) is obtained. This value is greater than the deformation parameter deduced from the lifetime measurement. With these two result combined, the ratio of the neutron and proton quadrupole matrix elements is deduced to be approximately 7, indicating a neutron-dominant quadrupole collectivity in 16C. [ABSTRACT FROM AUTHOR]

The stellar reaction 26Si(p,γ) 27P was studied in the Coulomb dissociation of 27P. Two known resonance levels in 27P were excited and a candidate for the third excited state was found in the 26Si p relative energy spectrum. The E2 resonance strengths wy were obtained to be (6.5 ± 1.3) x 10-11, (6.0 ± 1.1) x 10-10, and (1.10 ± 0.27) x 10-10 MeV. The total (E2 + M1) ϖγ value for the first excited state was evaluated to be Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed with the help of the shell model. The error was estimated from the deviation of theoretical predictions with the same shell model from experimental strengths obtained in the present study for 27P and earlier ones for the mirror nucleus 27Mg. The astrophysical reaction rate for the 26Si(p,γ) 27P reaction was also calculated and compared with previous estimations. [ABSTRACT FROM AUTHOR]

Abstract: The lifetime of the state at 2.1 MeV in 12Be has been measured using inelastic scattering of a 12Be beam at 43 MeV/nucleon with a gold target. Through the Doppler shift attenuation method, the mean-life of the state has been determined as (syst) ps, which gives a value of in Weisskopf units. The result shows a large quadrupole strength in the ground state transition, providing further evidence on the disappearance of the magic number. The value together with the deformation length measured by proton inelastic scattering yields a neutron quadrupole matrix element two times larger than those for 14C and 16O. [Copyright &y& Elsevier]

Abstract: The neutron-rich nucleus 13B was studied via the proton transfer reaction 4He(12Be, 13Bγ) at . The known 4.83-MeV excited state was strongly populated and its spin and parity were assigned to by comparing the angular differential cross section data with DWBA calculations. This low-lying state is interpreted as a proton intruder state and indicates a deformation of the nucleus. [Copyright &y& Elsevier]

The Coulomb dissociation of 27P was studied experimentally using 27P beams at 57 MeV/nucleon with a lead target. The E2 gamma decay width of the first excited state in 27P was extracted. Assuming the same E2/M1 mixing ratio as the one for the mirror nucleus 27Mg, the gamma decay width of the state, which is of astrophysical interest, is estimated to be ten times smaller than the value calculated by J. A. Caggiano et al. [Copyright &y& Elsevier]

The 1H(27F, 25,26,27F) reactions have been studied at average energy using a liquid hydrogen target. For 25F, 26F and 27F nuclei, we have observed two γ-ray peaks each originating from the decay of two bound excited states. This is the first sign of the existence of bound excited states in 26,27F. The presence of a single bound excited state in 27F is a clear indication of a substantial change in the structure of the fluorine isotopes approaching the neutron dripline. The proposed second excited states in 25,26,27F nuclei have no counterparts in either the or the shell model calculations suggesting the appearance of nuclear structure effects lying out of these model spaces. [Copyright &y& Elsevier]

The energy of the first excited state in the very neutron-rich nucleus 30Ne was determined via proton inelastic scattering. A liquid hydrogen target was bombarded by a radioactive 30Ne beam, and energies of the de-excitation γ rays emitted from excited 30Ne nuclei were measured. The observed transition is likely to be the one from the first 2+ state to the ground state of 30Ne. The excitation energy, 791 (26) keV, is lower than that of 32Mg, indicating an enhancement of deformation as the neutron excess increases in the N = 20 isotones. [Copyright &y& Elsevier]

The energy of the first excited state of the very neutron-rich nucleus 30Ne was determined by proton inelastic scattering. A liquid hydrogen target was bombarded by a beam of radioactive 30Ne at 48 MeV/nucleon, and energies of the de-excitation γ rays emitted from the excited 30Ne were measured. The observed transition is likely to be the one from the first 2+ state to the ground state of 30Ne. The excitation energy, 791(26) keV, is lower than that of 32Mg, indicating enhancement of deformation as the neutron excess increases in the N=20 isotones. The results indicate that 30Ne belongs to the ‘island of inversion’. [Copyright &y& Elsevier]

This Letter reports on the (1)H((28)Ne, (28)Ne) and (1)H((28)Ne, (27)Ne) reactions studied at intermediate energy using a liquid hydrogen target. From the cross section populating the first 2(+) excited state of (28)Ne, and using the previously determined BE(2) value, the neutron quadrupole transition matrix element has been calculated to be M(n)=13.8 +/- 3.7 fm(2). In the neutron knockout reaction, two low-lying excited states were populated in (27)Ne. Only one of them can be interpreted by the sd shell model while the additional state may intrude from the fp shell. These experimental observations are consistent with the presence of fp shell configurations at low excitation energy in (27,28)Ne nuclei caused by a vanishing N=20 shell gap at Z=10.

The electric quadrupole transition from the first 2(+) state to the ground 0(+) state in 16C is studied through measurement of the lifetime by a recoil shadow method applied to inelastically scattered radioactive 16C nuclei. The measured mean lifetime is 77+/-14(stat)+/-19(syst) ps. The central value of mean lifetime corresponds to a B(E2;2+(1)-->0(+)) value of 0.63e(2) fm(4), or 0.26 Weisskopf units. The transition strength is found to be anomalously small compared to the empirically predicted value.