Nuclear Theory·nucl-th

Wednesday·April 1, 2015

6 papers—3 primary·3 cross-listed

01
[Submitted on 31 Mar 2015]
Study of in-medium $η^{'}$ properties in the ( $γ$ , $η^{'} p$ ) reaction on nuclei
E. Ya. Paryev🇷🇺
We study the near-threshold photoproduction of $η^{'}$ mesons from nuclei in coincidence with forward going protons in the kinematical conditions of the Crystal Barrel/TAPS experiment, recently performed at ELSA. The calculations have been performed within a collision model based on the nuclear spectral function. The model accounts for both the primary $γ p \to η^{'} p$ process and the two-step intermediate nucleon rescattering processes as well as the effect of the nuclear $η^{'}$ mean-field potential. We calculate the exclusive $η^{'}$ kinetic energy distributions for the $^{12}$ C( $γ$ , $η^{'} p$ ) reaction for different scenarios of $η^{'}$ in-medium modification. We find that the considered two-step rescattering mechanism plays an insignificant role in $η^{'} p$ photoproduction off the carbon target. We also demonstrate that the calculated $η^{'}$ kinetic energy distributions in primary photon--proton $η^{'} p$ production reveal strong sensitivity to the depth of the real $η^{'}$ potential at normal nuclear matter density (or to the $η^{'}$ in-medium mass shift) in the studied incident photon energy regime. Therefore, such observables may be useful to help determine the above $η^{'}$ in-medium renormalization from the comparison of the results of our calculations with the data from the CBELSA/TAPS experiment. In addition, we show that these distributions are also strongly influenced by the momentum-dependent optical potential, which the outgoing participant proton feels inside the carbon nucleus. This potential should be taken into account in the analysis of these data with the aim to obtain information on the $η^{'}$ modification in cold nuclear matter.
Comments:
17 pages
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1503.09007 [pdf]
J.Phys.G(2016)·6 citations
02
[Submitted on 31 Mar 2015]
Shape coexistence and evolution in neutron-deficient krypton isotopes
Z. J. Bai · X. M. Fu · C. F. Jiao · F. R. Xu
Total Routhian Surface (TRS) calculations have been performed to investigate shape coexistence and evolution in neutron-deficient krypton isotopes $^{72, 74, 76}$ Kr. The ground-state shape is found to change from oblate in $^{72}$ Kr to prolate in $^{74, 76}$ Kr, in agreement with experimental data. Quadrupole deformations of the ground states and coexisting $0_{2}^{+}$ states as well as excitation energies of the latter are also well reproduced. While the general agreement between calculated moments of inertia and those deduced from observed spectra confirms the prolate nature of the low-lying yrast states of all three isotopes (except the ground state of $^{72}$ Kr), the deviation at low spins suggests significant shape mixing. The role of triaxiality in describing shape coexistence and evolution in these nuclei is finally discussed.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1503.09013 [pdf]
CPC(2015)·10 citations
03
[Submitted on 31 Mar 2015]
Multiquark interactions and heavy hybrid stars
Sanjin Benić🇯🇵
We introduce a two flavor Nambu--Jona-Lasinio (NJL) model with 8-quark interactions in the scalar and the vector channel. With the lower density region described by the density-dependent relativistic mean field model we construct a hybrid equation of state. We especially focus on the 4-quark vector couplings and the 8-quark vector NJL couplings and allocate a region in this parameter subspace where hybrid stars with masses larger than $2 M_{⊙}$ exist.
Comments:
5 pages, 3 figures, Proceedings of the "Compact Stars in the QCD phase diagram IV" workshop, Prerow, Germany, September 26 - 30, 2014
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1503.09145 [pdf]
0 citations

Affiliations

first authorsco-authorsvia INSPIRE

Study of in-medium η′ properties in the (γ, η′p) reaction on nuclei

Shape coexistence and evolution in neutron-deficient krypton isotopes

Multiquark interactions and heavy hybrid stars

Affiliations

Study of in-medium $η^{'}$ properties in the ( $γ$ , $η^{'} p$ ) reaction on nuclei