Nuclear Theory·nucl-th

Monday·October 12, 2015

9 papers—7 primary·2 cross-listed

01
Separable Forces for $(d, p)$ Reactions in Momentum Space
L. Hlophe · Ch. Elster · V. Eremenko · F. M. Nunes · I. J. Thompson · G. Arbanas · J. Escher
Treating $(d, p)$ reactions in a Faddeev-AGS framework requires the interactions in the sub-systems as input. We derived separable representations for the neutron- and proton-nucleus interactions from phenomenological global optical potentials. In order to take into account excitations of the nucleus, excitations need to be included explicity, leading to a coupled-channel separable representation of the optical potential.
nucl-thmath.CTEPJ Web Conf.(2016)·0 citations
02
Statistical error propagation in ab initio no-core full configuration calculations of light nuclei
R. Navarro Perez · J. E. Amaro · E. Ruiz Arriola · P. Maris🇺🇸 · J. P. Vary🇺🇸
We propagate the statistical uncertainty of experimental NN scattering data into the binding energy of $^{3}$ H and $^{4}$ He. We also study the sensitivity of the magnetic moment and proton radius of the $^{3}$ H to changes in the NN interaction. The calculations are made with the no-core full configuration method in a sufficiently large harmonic oscillator basis. For those light nuclei we obtain $Δ E$ ( $^{3}$ H) = 0.015 MeV and $Δ E$ ( $^{4}$ He) = 0.055 MeV.
nucl-thPRC(2015)·19 citations
03
A Study of Fluctuations of Voids in Relativistic Ion-Ion Collisions
Shakeel Ahmad🇮🇳 · M.M. Khan🇮🇳 · Shaista Khan🇮🇳 · A. Khatun🇮🇳 · M. Irfan🇮🇳
Event-by-event fluctuations (ebe) of hadronic patterns are investigated in terms of voids by analyzing the experimental data on 4.5, 14.5 and 60A GeV/c 16O-AgBr collisions. The findings are compared with the predictions of a multi-phase transport AMPT model. Dependence of voids on phase space bin width is examined in terms of two lowest moments of event-by-event fluctuations of voids, <Gq> and Sq. The findings reveal that scaling exponent estimated from the observed power-law behavior of the voids may be used to characterize the various properties of hadronic phase transition. The results also rule out occurrence of 2nd order quark-hadron phase transition at the projectile energies considered.
nucl-exhep-phnucl-thIJMPE(2015)·3 citations
04
Elastic photonuclear cross sections for bremsstrahlung from relativistic ions
R. E. Mikkelsen · A. H. Sørensen · U. I. Uggerhøj
In this paper, we provide a procedure to calculate the bremsstrahlung spectrum for virtually any relativistic bare ion with charge 6 $e$ or beyond, $Z \geq 6$ , in ultraperipheral collisions with target nuclei. We apply the Weizsäcker-Williams method of virtual quanta to model the effect of the distribution of nuclear constituents on the interaction of the ion with the radiation target. This leads to a bremsstrahlung spectrum peaking at $2 γ$ times the energy of the giant dipole resonance ( $γ$ is the projectile energy in units of its rest energy). A central ingredient in the calculation is the cross section for elastic scattering of photons on the ion. This is only available in the literature for a few selected nuclei and, usually, only in a rather restricted parameter range. Hence we develop a procedure applicable for all $Z \geq 6$ to estimate the elastic scattering. The elastic cross section is obtained at low to moderate photon energies, somewhat beyond the giant dipole resonance, by means of the optical theorem, a dispersion relation, and data on the total absorption cross section. The cross section is continued at higher energies by invoking depletion due to loss of coherence in the scattering. Our procedure is intended for any ion where absorption data is available and for moderate to high energies, $γ ≳ 10$ .
nucl-thNucl.Instrum.Meth.B(2016)·1 citation
05
Reexamining closed-form formulae for inclusive breakup: Application to deuteron and $^{6}$ Li induced reactions
Jin Lei🇪🇸 · Antonio M. Moro🇪🇸
The problem of the calculation of inclusive breakup cross sections in nuclear reactions is reexamined. For that purpose, the post-form theory proposed by Ichimura, Austern and Vincent [Phys. Rev. C32, 431 (1985) is revisited, and an alternative derivation of the non-elastic breakup part of the inclusive breakup is presented, making use of the coupled-channels optical theorem. Using the DWBA version of this model, several applications to deuteron and $^{6}$ Li reactions are presented and compared with available data. The validity of the zero-range approximation of the DWBA formula is also investigated by comparing zero-range with full finite-range calculations.
nucl-thPRC(2015)·108 citations
06
Transport coefficients and quark-hadron phase transition(s) from PLSM in vanishing and finite magnetic field
Abdel Nasser Tawfik (Egyptian Ctr. Theor. Phys., Cairo, WLCAPP, Cairo)🇪🇬
In peripheral heavy-ion collisions, localized ,short-lived an extremely huge magnetic field can be generated. Its possible influences on the quark-hadron phase transition(s) and the transport properties of the hadronic and partonic matter shall be analysed from the Polyakov linear-sigma model. Our calculations are compared with recent lattice QCD calculations.
nucl-thhep-lathep-phJ.Phys.Conf.Ser.(2016)·13 citations
07
Inclusive deuteron-induced reactions and final neutron states
Gregory Potel🇺🇸 · Filomena M. Nunes🇺🇸 · Ian J. Thompson🇺🇸
We present in this paper a formalism for deuteron-induced inclusive reactions. We disentangle direct elastic breakup contributions from other processes (which we generically call non-elastic breakup) implying a capture of the neutron both above and below the neutron emission threshold. The reaction is described as a two step process, namely the breakup of the deuteron followed by the propagation of the neutron-target system driven by an optical potential. The final state interaction between the neutron and the target can eventually form an excited compound nucleus. Within this context, the direct neutron transfer to a sharp bound state is a limiting case of the present formalism.
nucl-th1 citation
08
Modelling the nucleon structure
M. Burkardt (New Mexico State U.)🇺🇸 · B. Pasquini (Pavia U. and INFN-Pavia)🇮🇹
We review the status of our understanding of nucleon structure based on the modelling of different kinds of parton distributions. We use the concept of generalized transverse momentum dependent parton distributions and Wigner distributions, which combine the features of transverse-momentum dependent parton distributions and generalized parton distributions. We revisit various quark models which account for different aspects of these parton distributions. We then identify applications of these distributions to gain a simple interpretation of key properties of the quark and gluon dynamics in the nucleon.
↳ hep-phhep-exnucl-thEPJA(2016)·53 citations
09
BEC-BCS crossover in a cold and magnetized two color NJL model
Dyana C. Duarte🇧🇷 · P. G. Allen🇦🇷 · R. L. S. Farias🇧🇷 · Patrícia H. A. Manso🇧🇷 · Rudnei O. Ramos🇧🇷 · N. N. Scoccola🇦🇷
The BEC-BCS crossover for a NJL model with diquark interactions is studied in the presence of an external magnetic field. Particular attention is paid to different regularization schemes used in the literature. A thorough comparison of results is performed for the case of a cold and magnetized two-color NJL model. According to our results, the critical chemical potential for the BEC transition exhibits a clear inverse magnetic catalysis effect for magnetic fields in the range $1 ≲ e B / m_{π}^{2} ≲ 20$ . As for the BEC-BCS crossover, the corresponding critical chemical potential is very weakly sensitive to magnetic fields up to $e B \sim 9 m_{π}^{2}$ , showing a much smaller inverse magnetic catalysis as compared to the BEC transition, and displays a strong magnetic catalysis from this point on.
↳ hep-phcond-mat.supr-conhep-thnucl-thPRD(2016)·44 citations

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first authorsco-authorsvia INSPIRE