PaperPanorama
FAQ

Nuclear Theory·nucl-th

Friday·October 9, 2015

7 papers—5 primary·2 cross-listed

All7Primary5Cross-lists2
  1. 01

    Global description of beta-minus decay in even-even nuclei with the axially-deformed Skyrme finite amplitude method

    M.T. Mustonen · J. Engel

    We use the finite amplitude method for computing charge-changing Skyrme-QRPA transition strengths in axially-deformed nuclei together with a modern Skyrme energy-density functional to fit several previously unconstrained parameters in the charge-changing time-odd part of the functional. With the modified functional we then calculate rates of beta-minus decay for all medium-mass and heavy even-even nuclei between the valley of stability and the neutron drip line. We fit the Skyrme parameters to a limited set of beta-decay rates, a set of Gamow-Teller resonance energies, and a set of spin-dipole resonance energies, in both spherical and deformed nuclei. Comparison to available experimental beta-decay rates shows agreement at roughly the same level as in other global QRPA calculations. We estimate the uncertainty in our rates all the way to the neutron drip line through a construction that extrapolates the errors of known beta-decay rates in nuclei with intermediate Q values to less stable isotopes with higher Q values.

    nucl-thPRC(2016)·105 citations
  2. 02

    Interaction of the vector-meson octet with the baryon octet in effective field theory

    Y. Unal🇩🇪 · A. Kucukarslan🇹🇷 · S. Scherer🇩🇪

    We analyze the constraint structure of the interaction of vector mesons with baryons using the classical Dirac constraint analysis. We show that the standard interaction in terms of two independent SU(3) structures is consistent at the classical level. We then require the self-consistency condition of the interacting system in terms of perturbative renormalizability to obtain relations for the renormalized coupling constants at the one-loop level. As a result we find a universal interaction with one coupling constant which is the same as in the massive Yang-Mills Lagrangian of the vector-meson sector.

    nucl-thhep-phPRC(2015)·9 citations
  4. 04

    Search for Long-Range Correlations in Relativistic Heavy-Ion Collisions at SPS Energies

    Shakeel Ahmad🇮🇳 · Anisa Khatun🇮🇳 · Shaista Khan🇮🇳 · A. Ahmad🇮🇳 · M. Irfan🇮🇳

    Long range correlations are searched for by analyzing the experimental data on 16O-AgBr and 32S-AgBr collisions at 200A GeV/c and the results are compared with the predictions of a multi phase transport (AMPT) model. The findings reveal that the observed forward-backward (F-B) multiplicity correlations are mainly of short-range in nature. The range of F-B correlations are observed to extend with increasing projectile mass. The observed extended range of F-B correlations might be due to overall multiplicity fluctuations arising because of nuclear geometry. The findings are not sufficient for making any definite conclusions regarding the presence of long-range correlations.

    nucl-exhep-phnucl-thAdv.High Energy Phys.(2015)·4 citations
  5. 05

    Effective field theory for nuclear vibrations with quantified uncertainties

    E. A. Coello Pérez · T. Papenbrock

    We develop an effective field theory (EFT) for nuclear vibrations. The key ingredients - quadrupole degrees of freedom, rotational invariance, and a breakdown scale around the three-phonon level - are taken from data. The EFT is developed for spectra and electromagnetic moments and transitions. We employ tools from Bayesian statistics for the quantification of theoretical uncertainties. The EFT consistently describes spectra and electromagnetic transitions for Ni, Ru, Pd, Cd, and Te within the theoretical uncertainties. This suggests that these nuclei can be viewed as anharmonic vibrators.

    nucl-thnucl-exPRC(2015)·57 citations
  6. 06

    Velocity-induced Heavy Quarkonium Dissociation using the gauge-gravity correspondence

    Binoy Krishna Patra🇮🇳 · Himanshu Khanchandani🇮🇳 · Lata Thakur🇮🇳

    Using the gauge-gravity duality we have obtained the potential between a heavy quark and an antiquark pair, which is moving perpendicular to the direction of orientation, in a strongly-coupled supersymmetric hot plasma. For the purpose we work on a metric in the gravity side, {\em viz.} OKS-BH geometry, whose dual in the gauge theory side runs with the energy and hence proves to be a better background for thermal QCD. The potential obtained has confining term both in vacuum and in medium, in addition to the Coulomb term alone, usually reported in the literature. As the velocity of the pair is increased the screening of the potential gets weakened, which may be understood by the decrease of effective temperature with the increase of velocity. The crucial observation of our work is that beyond a critical separation of the heavy quark pair, the potential develops an imaginary part which is nowadays understood to be the main source of dissociation. The imaginary part is found to vanish at small , thus agrees with the perturbative result. Finally we have estimated the thermal width for the ground and first excited states and found that non-zero rapidities lead to an increase of thermal width. This implies that the moving quarkonia dissociate easier than the static ones, which agrees with other calculations. However, the width in our case is larger than other calculations due to the presence of confining terms.

    ↳ hep-thhep-phnucl-thPRD(2015)·18 citations
  7. 07

    Composite Vector Particles in External Electromagnetic Fields

    Zohreh Davoudi🇺🇸 · William Detmold🇺🇸

    Lattice quantum chromodynamics (QCD) studies of electromagnetic properties of hadrons and light nuclei, such as magnetic moments and polarizabilities, have proven successful with the use of background field methods. With an implementation of nonuniform background electromagnetic fields, properties such as charge radii and higher electromagnetic multipole moments (for states of higher spin) can be additionally obtained. This can be achieved by matching lattice QCD calculations to a corresponding low-energy effective theory that describes the static and quasi-static response of hadrons and nuclei to weak external fields. With particular interest in the case of vector mesons and spin-1 nuclei such as the deuteron, we present an effective field theory of spin-1 particles coupled to external electromagnetic fields. To constrain the charge radius and the electric quadrupole moment of the composite spin-1 field, the single-particle Green's functions in a linearly varying electric field in space are obtained within the effective theory, providing explicit expressions that can be used to match directly onto lattice QCD correlation functions. The viability of an extraction of the charge radius and the electric quadrupole moment of the deuteron from the upcoming lattice QCD calculations of this nucleus is discussed.

    ↳ hep-lathep-phnucl-thPRD(2016)·7 citations

Affiliations

first authorsco-authorsvia INSPIRE