Nuclear Theory·nucl-th
5 papers—2 primary·3 cross-listed
J. Piekarewicz · F.J. Fattoyev
Despite a length-scale difference of 18 orders of magnitude, the internal structure of neutron stars and the spatial distribution of neutrons in atomic nuclei are profoundly connected.
S.Frauendorf · M. Beard · M. Mumpower · R. Schwengner · K. Wimmer
A pronounced spike at low energy in the strength function for magnetic radiation (LEMAR) is found by means of Shell Model calculations, which explains the experimentally observed enhancement of the dipole strength. LEMAR originates from statistical low-energy M1-transitions between many excited complex states. Re-coupling of the proton and neutron high-j orbitals generates the strong magnetic radiation. LEMAR is predicted for nuclides with participating in the r-process of element synthesis. It increases the reaction rates by a factor of 2.5. The spectral function of LEMAR follows Planck's Law. A power law for the size distribution of the values are found.
P. Cirkovic🇷🇸 · J. Milosevic🇷🇸 · L. Nadderd🇷🇸 · F. Wang🇨🇳 · X. Zhu🇨🇳
The elliptic flow () event-by-event fluctuations in PbPb collisions at 5.02~TeV are analyzed within the HYDJET++ model. Using the multi-particle, so called Q-cumulant method, , , and are calculated and used to study their ratios and to construct skewness () as a measure of the asymmetry of the elliptic flow distribution. Additionally, in order to check if there is a hydrodynamics nature in the elliptic collectivity generated by the HYDJET++ model, the ratio of and distribution is calculated. The analysis is performed as a function of the collision centrality. In order to check the HYDJET++ model responses, the results of this analysis are compared to the corresponding experimental measurements by CMS. A good qualitative and rather good quantitative agreement is found.
Chia-Jung Yeh · Po-Han Lin · Xiwen Zhang · Olga Kocharovskaya · Wen-Te Liao
Two kinds of spectral control over -ray echo using a nuclear frequency comb system are theoretically investigated. A nuclear frequency comb system is composed of multiple nuclear targets under magnetization (hyperfine splitting), mechanical motion (Doppler shift) or both, namely, moving and magnetized targets. In frequency domain the unperturbed single absorption line of -ray therefore splits into multiple lines with equal spacing and becomes a nuclear frequency comb structure. We introduce spectral shaping and dynamical splitting to the frequency comb structure respectively to optimize the use of a medium and to break the theoretical maximum of echo efficiency, i.e., 54\%. Spectral shaping scheme leads to the reduction of required sample resonant thickness for achieving high echo efficiency of especially a broadband input. Dynamical splitting method significantly advances the echo efficiency up to 67\% revealed by two equivalent nuclear frequency comb systems. We also show that using only few targets is enough to obtain good echo performance, which significantly eases the complexity of implementation. Our results extend quantum optics to 10keV regime and lay the foundation of the development of -ray memory.
Vivek Kumar Singh🇮🇳 · D. K. Mishra🇮🇳 · Zubayer Ahammed🇮🇳
We study the fluctuations of net-charge, net-pion, net-kaon and net-proton using -measure and variables in heavy-ion jet interaction generator (HIJING), ultra-relativistic quantum molecular dynamics (UrQMD), and hadron resonance gas (HRG) model at different collision energies \sqsn. It has been observed that, the values of strongly dependent on in HIJING and UrQMD models and independent in HRG model. The diffusion coefficients () of identified particles are estimated at various \sqsn. It is observed that, the values are independent of collision energies but emphasizes the particle species dependence of diffusion coefficient in the QGP medium. This study provides a realistic baseline for comparison with the experimental data.
first authorsco-authorsvia INSPIRE