Nuclear Theory·nucl-th

Thursday·May 19, 2016

9 papers—6 primary·3 cross-listed

01
An Improved Method of Lifetime Measurement of Nuclei in Radioactive Decay Chain
J. M. Puzović (1) · D. Manić (1) · L. J. Na{\dj}{\dj}er{\dj} (2) ((1) Faculty of Physics, University of Belgrade, Belgrade, Serbia, (2) Institute of Nuclear Sciences Vinča, Belgrade, Serbia)
We present an improved statistical method for calculation of mean lifetime of nuclei in a decay chain with uncertain relation between mother and daughter nuclei. The method is based on formation of time distribution of intervals between mother and daughter nuclei, without trying to set the exact mother-daughter nuclei relationship. If there is a coincidence of mother and daughter nuclei decays, sum of these distributions has flat term on which an exponential term is superimposed. Parameters of this exponential function allow lifetime of daughter nucleus to be extracted. The method is tested on Monte Carlo simulation data.
nucl-thNucl.Instrum.Meth.A(2017)·0 citations
02
Comment on "Solution of the $α$ -Potential Mystery in the $γ$ Process and Its Impact on the Nd/Sm Ratio in Meteorites"
V. Avrigeanu · M. Avrigeanu · C. Mănăilescu
A competition of the low-energy Coulomb excitation (CE) with the compound nucleus (CN) formation in $α$ -induced reactions below the Coulomb barrier has been assumed by Rauscher [Phys. Rev. Lett. 111, 061104 (2013)] in order to use the same optical model (OM) potential for description of the latter and the alpha-particle emission as well. In this Comment we show that the corresponding partial waves and integration radii provide evidence for the distinct account of the CE cross section and OM total-reaction cross section.
nucl-thnucl-ex8 citations
03
Structure and decay pattern of linear-chain state in 14C
T. Baba · M. Kimura
The linear-chain states of $^{14}$ C are theoretically investigated by using the antisymmetrized molecular dynamics. The calculated excitation energies and the $α$ decay widths of the linear-chain states were compared with the observed data reported by the recent experiments. The properties of the positive-parity linear-chain states reasonably agree with the observation, that convinces us of the linear-chain formation in the positive-parity states. On the other hand, in the negative-parity states, it is found that the linear-chain configuration is fragmented into many states and do not form a single rotational band. As a further evidence of the linear-chain formation, we focus on the $α$ decay pattern. It is shown that the linear-chain states decay to the excited states of daughter nucleus $^{10} Be$ as well as to the ground state, while other cluster states dominantly decay into the ground state. Hence, we regard that this characteristic decay pattern is a strong signature of the linear-chain formation.
nucl-thPRC(2016)·44 citations
04
Drag induced radiative energy loss of semi-hard heavy quarks
Raktim Abir · Shanshan Cao · Abhijit Majumder · Guang-You Qin
We revisited gluon bremsstrahlung off a heavy quark in nuclear matter within higher twist formalism. In this work, we demonstrate that, in addition to transverse momentum diffusion parameter ( $q^$ ), the gluon emission spectrum for a heavy quark is quite sensitive to $e^$ , which quantify the amount of light-cone drag experienced by a parton. This effect leads to an additional energy loss term for heavy-quarks. From heavy flavor suppression data in ultra-relativistic heavy-ion collisions one can now estimate the value of this sub-leading non-perturbative jet transport parameter ( $e^$ ) from our results.
nucl-thNucl.Part.Phys.Proc.(2016)·0 citations
05
Sensitivity of {\Lambda} single-particle energies to the {\Lambda}N spin-orbit coupling and to nuclear core structure in p-shell and sd-shell hypernuclei
P. Veselý🇨🇿 · E. Hiyama🇯🇵 · J. Hrtánková🇨🇿 · J. Mareš🇨🇿
We introduce a mean field model based on realistic 2-body baryon interactions and calculate spectra of a set of p-shell and sd-shell {\Lambda} hypernuclei - 13{\Lambda}C, 17{\Lambda}O, 21{\Lambda}Ne, 29{\Lambda}Si and 41{\Lambda}Ca. The hypernuclear spectra are compared with the results of a relativistic mean field (RMF) model and available experimental data. The sensitivity of {\Lambda} single-particle energies to the nuclear core structure is explored. Special attention is paid to the effect of spin-orbit {\Lambda}N interaction on the energy splitting of the {\Lambda} single particle levels 0p3/2 and 0p1/2. In particular, we analyze the contribution of the symmetric (SLS) and the anti-symmetric (ALS) spin-orbit terms to the energy splitting. We give qualitative predictions for the calculated hypernuclei.
nucl-thNPA(2016)·9 citations
06
Muon capture on 3H
J. Golak · R. Skibinski · H. Witala · K. Topolnicki · H. Kamada · A. Nogga · L.E. Marcucci
The muon capture on 3H leading to muonic neutrino and three neutrons in the final state is studied under full inclusion of final state interactions. Predictions for the three-body break-up of 3H are calculated with the AV18 potential, augmented by the Urbana IX three-nucleon force. Our results are based on the single nucleon weak current operator comprising the dominant relativistic corrections. This work is a natural extension of our investigations of the muon capture on 3He leading to 3H or n+d or n+n+p and muonic neutrino in the final state, presented in Phys. Rev. C90, 024001 (2014).
nucl-thPRC(2016)·15 citations
07
From Inverse to Delayed Magnetic Catalysis in Strong Magnetic Field
Shijun Mao🇨🇳
We study magnetic field effect on chiral phase transition in a Nambu--Jona-Lasinio model. In comparison with mean field approximation containing quarks only, including mesons as quantum fluctuations in the model leads to a transition from inverse to delayed magnetic catalysis at finite temperature and delays the transition at finite baryon chemical potential. The location of the critical end point depends on the the magnetic field non-monotonously.
↳ hep-thhep-phnucl-thPRD(2016)·36 citations
08
Scalar and vector self-energies of heavy baryons in nuclear medium
K. Azizi🇹🇷 · N. Er🇹🇷 · H. Sundu🇹🇷
The in-medium sum rules are employed to calculate the shifts in the mass and residue as well as the scalar and vector self-energies of the heavy $Λ_{Q}, Σ_{Q}$ and $Ξ_{Q}$ baryons, with Q being $b$ or $c$ quark. The maximum shift in mass due to nuclear matter belongs to the $Σ_{c}$ baryon and it is found to be $Δ m_{Σ_{c}} = - 936 M e V$ . In the case of residue, it is obtained that the residue of $Σ_{b}$ baryon is maximally affected by the nuclear medium with the shift $Δ λ_{Σ_{b}} = - 0.014 G e V^{3}$ . The scalar and vector self-energies are found to be $Σ_{Λ_{b}}^{S} = 653 M e V$ , $Σ_{Σ_{b}}^{S} = - 614 M e V$ , $Σ_{Ξ_{b}}^{S} = - 17 M e V$ , $Σ_{Λ_{c}}^{S} = 272 M e V$ , $Σ_{Σ_{c}}^{S} = - 936 M e V$ , $Σ_{Ξ_{c}}^{S} = - 5 M e V$ and $Σ_{Λ_{b}}^{ν} = 436 \pm 148 M e V$ , $Σ_{Σ_{b}}^{ν} = 382 \pm 129 M e V$ , $Σ_{Ξ_{b}}^{ν} = 15 \pm 5 M e V$ , $Σ_{Λ_{c}}^{ν} = 151 \pm 45 M e V$ , $Σ_{Σ_{c}}^{ν} = 486 \pm 144 M e V$ and $Σ_{Ξ_{c}}^{ν} = 1.391 \pm 0.529 M e V$ .
↳ hep-phnucl-thNPA(2017)·20 citations
09
Forward $J / ψ$ production at high energy: centrality dependence and mean transverse momentum
B. Ducloué🇫🇮 · T. Lappi🇫🇮 · H. Mäntysaari🇺🇸
Forward rapidity $J / ψ$ meson production in proton-nucleus collisions can be an important constraint of descriptions of the small- $x$ nuclear wavefunction. In an earlier work we studied this process using a dipole cross section satisfying the Balitsky-Kovchegov equation, fit to HERA inclusive data and consistently extrapolated to the nuclear case using a standard Woods-Saxon distribution. In this paper we present further calculations of these cross sections, studying the mean transverse momentum of the meson and the dependence on collision centrality. We also extend the calculation to backward rapidities using nuclear parton distribution functions. We show that the parametrization is overall rather consistent with the available experimental data. However, there is a tendency towards a too strong centrality dependence. This can be traced back to the rather small transverse area occupied by small- $x$ gluons in the nucleon that is seen in the HERA data, compared to the total inelastic nucleon-nucleon cross section.
↳ hep-phnucl-thPRD(2016)·51 citations

Affiliations

first authorsco-authorsvia INSPIRE