Nuclear Experiment·nucl-ex
4 papers—0 primary·4 cross-listed·reconstructed*
Xiao-Dong Sun · Ping Guo · Xiao-Hua Li
decay occurs in both ground states and isomers of nuclei. In this work, we use the two-potential approach to systematically study whether isomeric states play a key role on particle clustering or not. The results indicate the ratios of decay preformation probabilities of isomers to ground states are found to be around 1.
Yin Xia🇨🇳 · Jun Xu🇨🇳 · Bao-An Li🇺🇸 · Wen-Qing Shen🇨🇳
A consistent derivation of the equations of motion (EOMs) of test particles for solving the spin-dependent Boltzmann-Vlasov equation is presented. The resulting EOMs in phase space are similar to the canonical equations in Hamiltonian dynamics, and the EOM of spin is the same as that in the Heisenburg picture of quantum mechanics. Considering further the quantum nature of spin and choosing the direction of total angular momentum in heavy-ion reactions as a reference of measuring nucleon spin, the EOMs of spin-up and spin-down nucleons are given separately. The key elements affecting the spin dynamics in heavy-ion collisions are identified. The resulting EOMs provide a solid foundation for using the test-particle approach in studying spin dynamics in heavy-ion collisions at intermediate energies. Future comparisons of model simulations with experimental data will help constrain the poorly known in-medium nucleon spin-orbit coupling relevant for understanding properties of rare isotopes and their astrophysical impacts.
Shung-Ichi Ando (Sunmoon U.)🇰🇷
The elastic -C scattering at low energies is studied employing an effective field theory in which the and C states are treated as elementary-like fields. We discuss scales of the theory at stellar energy region that the C(, )O process occurs, and then obtain an expression of the elastic scattering amplitudes in terms of effective range parameters. Using experimental data of the phase shifts for channels at low energies, for which the resonance regions are avoided, we fix values of the parameters and find that the phase shifts at the low energies are well reproduced by using three effective range parameters for each channel. Furthermore, we discuss problems and uncertainties of the present approach when the amplitudes are extrapolated to the stellar energy region.
J.W. Zhao🇨🇳 · B.H. Sun🇨🇳 · I. Tanihata🇯🇵 · S. Terashima🇨🇳 · L.H. Zhu🇨🇳 · A. Enomoto · D. Nagae🇯🇵 · T. Nishimura · S. Omika · A. Ozawa🇯🇵 · Y. Takeuchi🇯🇵 · T. Yamaguchi🇯🇵
Timing-pick up detectors with excellent timing resolutions are essential in many modern nuclear physics experiments. Aiming to develop a Time-Of-Flight system with precision down to about 10 ps, we have made a systematic study of the timing characteristic of TOF detectors, which consist of several combinations of plastic scintillators and photomultiplier tubes. With the conventional electronics, the best timing resolution of about 5.1 ps ({\sigma}) has been achieved for detectors with an area size of 3x1 cm2. It is found that for data digitalization a combination of TAC and ADC can achieve a better time resolution than currently available TDC. Simultaneously measurements of both time and pulse height are very valuable for correction of time-walk effect.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.