Nuclear Theory·nucl-th

Tuesday·October 25, 2016

17 papers—12 primary·5 cross-listed

13
[Submitted on 22 Oct 2016] (cross-list from nucl-ex)
Sensitivity of stellar electron-capture rates to parent neutron number: A case study on a continuous chain of twenty Vanadium isotopes
G. W. Hitt · S. Gupta · R. G. T. Zegers · R. Titus · C. Sullivan · B. A. Brown · A. L. Cole · S. Shams
Gamow-Teller (GT) strength distributions (B(GT)) in electron-capture (EC) daughters stemming from the parent ground state are computed with the shell-model in the full pf-shell space, with quasi-particle random-phase approximation (QRPA) in the formalism of Krumlinde and Möller and with an Approximate Method (AM) for assigning an effective B(GT). These are compared to data available from decay and charge-exchange (CE) experiments across titanium isotopes in the pf-shell from A=43 to A=62, the largest set available for any chain of isotopes in the pf-shell. The present study is the first to examine B(GT) and the associated EC rates across a particular chain of isotopes with the purpose of examining rate sensitivities as neutron number increases. EC rates are also computed for a wide variety of stellar electron densities and temperatures providing concise estimates of the relative size of rate sensitivities for particular astrophysical scenarios. This work underscores the astrophysical motivation for CE experiments in inverse kinematics for nuclei away from stability at the luminosities of future Radioactive Ion Beam Facilities.
Comments:
12 pages, 9 figures, submitted to Physical Review C
Subjects:
Nuclear Experiment (nucl-ex); Solar and Stellar Astrophysics (astro-ph.SR); Nuclear Theory (nucl-th)
arXiv:
1610.06992 [pdf]
1 citation
14
[Submitted on 22 Oct 2016] (cross-list from hep-ph)
Production of charmed baryon $Λ_{c} (2940)$ by kaon-induced reaction on a proton target
Yin Huang · Jun He · Ju-Jun Xie · Xurong Chen · Hong-Fei Zhang
We investigate the possibility to study the charmed baryon $Λ_{c} (2940)$ by kaon-induced reaction on a proton target. By assuming the $Λ_{c} (2940)$ as a $p D^{* 0}$ molecular state with spin-parity $J^{p} = 1/ 2^{\pm}$ , an effective Lagrangian approach was adopted to calculate the cross section, the $D^{0} p$ invariant mass spectrum and Dalitz plot of the $Λ (2940)$ production. The total cross section of the $K^{-} p \to Λ_{c} (2940) D_{s}^{-}$ reaction is found at an order of magnitude about 10 $μ$ b. By considering the sub sequential decay $Λ_{c} (2940) \to D^{0} p$ with contributions from the $Λ_{c} (2286)$ and the $Σ_{c} (2455)$ as background, the $K^{-} p \to D_{s}^{-} D^{0} p$ reaction are studied. It is found that the $Λ_{c} (2940)$ is produced mainly at forward angles. The $Λ_{c} (2940)$ signal is predicted to be significant in the $D^{0} p$ invariant mass spectrum and the Dalitz plot of the $K^{-} p \to D_{s}^{-} D^{0} p$ reaction. The results suggest that it is promising to study the $Λ_{c} (2940)$ with high-energy kaon beam on a proton target in experiment.
Comments:
6 pages, 6 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1610.06994 [pdf]
PRD(2019)·19 citations
15
[Submitted on 24 Oct 2016] (cross-list from nucl-ex)
Directed flow of $Λ$ , $Λ ˉ$ , $K^{\pm}$ , $K_{S}^{0}$ and $ϕ$ mesons from Beam Energy Scan Au+Au collisions using the STAR experiment
Subhash Singha (for the STAR collaboration)🇺🇸
We report the results of $v_{1}$ and $d v_{1} / d y$ near mid-rapidity for $Λ$ , $Λ ˉ$ , $K^{\pm}$ , $K_{s}^{0}$ and $ϕ$ in Au+Au collisions at $s_{NN}$ = 7.7, 11.5, 14.5, 19.6, 27 and 39~GeV using the STAR detector at RHIC. The $d v_{1} / d y$ of $Λ$ is found to be consistent with that of the proton and shows a change in sign near $s_{NN} = 11.5$ ~GeV. The $v_{1}$ slope for $Λ ˉ$ , $p ˉ$ and $ϕ$ shows a similar trend for $s_{NN}$ $>$ 14.5~GeV, while below 14.5~GeV, $ϕ$ $v_{1}$ is consistent with zero but with a large uncertainty. The $d v_{1} / d y$ for net protons and net kaons is similar for $s_{NN} >$ 14.5~GeV, but they deviate at lower beam energies.
Comments:
4 pages, 5 figures, to appear in Strangeness in Quark Matter 2016 proceedings
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1610.07423 [pdf]
J.Phys.Conf.Ser.(2017)·3 citations
16
[Submitted on 24 Oct 2016] (cross-list from hep-ph)
Partial Wave Decomposition in Friedrichs Model With Self-interacting Continua
Zhiguang Xiao🇨🇳 · Zhi-Yong Zhou🇨🇳
We consider the nonrelativistic model of coupling bare discrete states with continuum states in which the continuum states can have interactions among themselves. By partial-wave decomposition and constraint to the conserved angular momentum eigenstates, the model can be reduced to Friedrichs-like model with additional interactions between the continua. If a kind of factorizable form factor is chosen, the model can be exactly solvable, that is, the generalized discrete eigenstates including bound states, virtual states, and resonances, can all be represented using the original bare states, and so do the in-state and out-state. The exact $S$ matrix is thus obtained. We then discuss the behaviors of the dynamically generated $S$ -wave and $P$ -wave discrete states as the coupling is varying when there is only one self-interacting bare continuum state. We find that even when the potential is repulsive there could also be resonances and virtual states. In the $P$ -wave cases with attractive interaction, we find that when there is a near-threshold bound state, there will always be an accompanying virtual state and we also give a more general argument of this effect.
Comments:
13 pages, 6 figures, publication version
Subjects:
High Energy Physics — Phenomenology (hep-ph); Mathematical Physics (math-ph); math.MP (math.MP); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
1610.07460 [pdf]
J.Math.Phys.(2017)·21 citations
17
[Submitted on 24 Oct 2016] (cross-list from nucl-ex)
Baryon-Strangeness Correlations in Au+Au Collisions at $s_{NN}$ =7.7-200 GeV from the UrQMD model
Zhenzhen Yang🇨🇳 · Xiaofeng Luo🇨🇳 · Bedangadas Mohanty🇮🇳
Fluctuations and correlations of conserved charges are sensitive observables for studying the QCD phase transition and critical point in high-energy heavy-ion collisions. We have studied the centrality and energy dependence of mixed-cumulants (up to fourth order) between net-baryon and net-strangeness in Au+Au collisions at $s_{N N}$ = 7.7, 11.5, 19.6, 27, 39, 62.4, 200 GeV from UrQMD model. To compare with other theoretical calculations, we normalize these mixed-cumulants by various order cumulants of net-strangeness distributions. We found that the results obtained from UrQMD calculations are comparable with the results from Lattice QCD at low temperature and hadron resonance gas model. The ratios of mixed-cumulants ( $R_{11}^{B S}, R_{13}^{B S}, R_{22}^{B S}$ ,~ $R_{31}^{B S}$ ) from UrQMD calculations show weak centrality dependence. However, the mixed-cumulant ratios $R_{11}^{B S}$ and $R_{31}^{B S}$ show strong increase at low energy, while the $R_{13}^{B S}$ snd $R_{22}^{B S}$ are similar at different energies. Furthermore, we have also studied the correlations between different hadron species and their contributions to the net-baryon and net-strangeness correlations. These models studies can provide baselines for searching for the signals of QCD phase transition and critical point in heavy-ion collisions.
Comments:
11 pages, 5 figures
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1610.07580 [pdf]
PRC(2017)·14 citations

Affiliations

first authorsco-authorsvia INSPIRE

Sensitivity of stellar electron-capture rates to parent neutron number: A case study on a continuous chain of twenty Vanadium isotopes

Production of charmed baryon Λc​(2940) by kaon-induced reaction on a proton target

Directed flow of Λ, Λˉ, K±, KS0​ and ϕ mesons from Beam Energy Scan Au+Au collisions using the STAR experiment

Partial Wave Decomposition in Friedrichs Model With Self-interacting Continua

Baryon-Strangeness Correlations in Au+Au Collisions at sNN​​=7.7-200 GeV from the UrQMD model

Affiliations

Production of charmed baryon $Λ_{c} (2940)$ by kaon-induced reaction on a proton target

Directed flow of $Λ$ , $Λ ˉ$ , $K^{\pm}$ , $K_{S}^{0}$ and $ϕ$ mesons from Beam Energy Scan Au+Au collisions using the STAR experiment

Baryon-Strangeness Correlations in Au+Au Collisions at $s_{NN}$ =7.7-200 GeV from the UrQMD model