PaperPanorama

Nuclear Theory·nucl-th

Wednesday·October 21, 2020

8 papers4 primary·4 cross-listed

  1. 05

    Solving relativistic three-body integral equations in the presence of bound states

    Andrew W. Jackura🇺🇸 · Raúl A. Briceño🇺🇸 · Sebastian M. Dawid🇺🇸 · Md Habib E Islam🇺🇸 · Connor McCarty🇺🇸

    We present a systematically improvable method for numerically solving relativistic three-body integral equations for the partial-wave projected amplitudes. The method consists of a discretization procedure in momentum space, which approximates the continuum problem with a matrix equation. It is solved for different matrix sizes, and in the end, an extrapolation is employed to restore the continuum limit. Our technique is tested by solving a three-body problem of scalar particles with an wave two-body bound state. We discuss two methods of incorporating the pole contribution in the integral equations, both of them leading to agreement with previous results obtained using finite-volume spectra of the same theory. We provide an analytic and numerical estimate of the systematic errors. Although we focus on kinematics below the three-particle threshold, we provide numerical evidence that the methods presented allow for determination of amplitude above this threshold as well.

    hep-lathep-phnucl-thPRD(2021)·61 citations
  2. 06

    An integral-free representation of the Dyson series using divided differences

    Amir Kalev🇺🇸 · Itay Hen🇺🇸

    The Dyson series is an infinite sum of multi-dimensional time-ordered integrals, which serves as a formal representation of the quantum time-evolution operator in the interaction-picture. Using the mathematical tool of divided differences, we introduce an alternative representation for the series that is entirely free from both time ordering and integrals. In this new formalism, the Dyson expansion is given as a sum of efficiently-computable divided differences of the exponential function, considerably simplifying the calculation of the Dyson expansion terms, while also allowing for time-dependent perturbation calculations to be performed directly in the Schrödinger-picture. We showcase the utility of this novel representation by studying a number of use cases. We also discuss several immediate applications.

    quant-phcond-mat.stat-mechhep-thmath-ph+2New J.Phys.(2021)·12 citations
  3. 07

    Signatures of clustering in O by using a multiphase transport model

    Yi-An Li🇨🇳 · Song Zhang🇨🇳 · Yu-Gang Ma🇨🇳

    -clustered structures in light nuclei could be studied through "snapshots" taken by relativistic heavy-ion collisions. A multiphase transport (AMPT) model is employed to simulate the initial structure of collision nuclei and the proceeding collisions at center of mass energy = 6.37 TeV. This initial structure can finally be reflected in the subsequent observations, such as elliptic flow (), triangular flow () and quadrangular flow (). Three sets of the collision systems are chosen to illustrate system scan is a good way to identify the exotic -clustered nuclear structure, case I: nucleus (with or without -cluster) + ordinary nuclei (always in Woods-Saxon distribution) in most central collisions, case II: nucleus (with or without -cluster) + nucleus collisions for centrality dependence, and case III: symmetric collision systems (namely, B + B, C + C, O + O (with or without -cluster), Ne + Ne, and Ca + Ca) in most central collisions. Our calculations propose that relativistic heavy-ion collision experiments at = 6.37 TeV are promised to distinguish the tetrahedron structure of from the Woods-Saxon one and shed lights on the system scan projects in experiments.

    hep-phnucl-exnucl-thPRC(2020)·62 citations
  4. 08

    Medium evolution of a static quark-antiquark pair in the large limit

    Miguel Ángel Escobedo🇪🇸

    We study the transitions between the different color states of a static quark-antiquark pair, singlet and octet, in a thermal medium. This is done non-perturbatively exploiting the infinite mass limit of QCD. This study is interesting because it can be used for future developments within the framework of Effective Field Theories (EFTs) and because it can be combined with other techniques, like lattice QCD or AdS/CFT, to gain non-perturbative information about the evolution of quarkonium in a medium. We also study the obtained expressions in the large limit. This allows us to learn lessons that are useful to simplify phenomenological models of quarkonium in a plasma.

    hep-phnucl-thPRD(2021)·13 citations

Affiliations

first authorsco-authorsvia INSPIRE