PaperPanorama
FAQ

Nuclear Theory·nucl-th

Friday·July 9, 2021

10 papers—5 primary·5 cross-listed

All10Primary5Cross-lists5
  1. 06

    Vector-meson production and vector meson dominance

    Yin-Zhen Xu🇨🇳 · Si-Yang Chen🇨🇳 · Zhao-Qian Yao🇨🇳 · Daniele Binosi🇮🇹 · Zhu-Fang Cui🇨🇳 · Craig D. Roberts🇨🇳

    We consider the fidelity of the vector meson dominance (VMD) assumption as an instrument for relating the electromagnetic vector-meson production reaction to the purely hadronic process . Analyses of the photon vacuum polarisation and the photon-quark vertex reveal that such a VMD Ansatz might be reasonable for light vector-mesons. However, when the vector-mesons are described by momentum-dependent bound-state amplitudes, VMD fails for heavy vector-mesons: it cannot be used reliably to estimate either a photon-to-vector-meson transition strength or the momentum dependence of those integrands that would arise in calculations of the different reaction amplitudes. Consequently, for processes involving heavy mesons, the veracity of both cross-section estimates and conclusions based on the VMD assumption should be reviewed, e.g., those relating to hidden-charm pentaquark production and the origin of the proton mass.

    ↳ hep-phhep-exhep-latnucl-ex+1EPJC(2021)·66 citations
  2. 07

    Nuclear fission chain reaction in cooling white dwarf stars

    C. J. Horowitz · M. E. Caplan

    The first solids that form as a white dwarf (WD) starts to crystallize are expected to be greatly enriched in actinides. Previously [PRL 126, 1311010] we found that these solids might support a nuclear fission chain reaction that could ignite carbon burning and provide a new Type Ia supernova (SN Ia) mechanism involving an {\it isolated} WD. Here we explore this fission mechanism in more detail and calculate the final temperature and density after the chain reaction and discuss a number of open physics questions.

    ↳ astro-ph.SRastro-ph.HEnucl-th3 citations
  3. 08

    Quantum Many-Body Calculations using Body-Centered Cubic Lattices

    Young-Ho Song🇰🇷 · Youngman Kim🇰🇷 · Ning Li🇨🇳 · Bing-Nan Lu🇨🇳 · Rongzheng He🇺🇸 · Dean Lee🇺🇸

    It is often computationally advantageous to model space as a discrete set of points forming a lattice grid. This technique is particularly useful for computationally difficult problems such as quantum many-body systems. For reasons of simplicity and familiarity, nearly all quantum many-body calculations have been performed on simple cubic lattices. Since the removal of lattice artifacts is often an important concern, it would be useful to perform calculations using more than one lattice geometry. In this work we show how to perform quantum many-body calculations using auxiliary-field Monte Carlo simulations on a three-dimensional body-centered cubic (BCC) lattice. As a benchmark test we compute the ground state energy of 33 spin-up and 33 spin-down fermions in the unitary limit, which is an idealized limit where the interaction range is zero and scattering length is infinite. As a fraction of the free Fermi gas energy , we find that the ground state energy is using two different definitions of the finite-system energy ratio. This is in excellent agreement with recent results obtained on a cubic lattice \cite{He:2019ipt}. We find that the computational effort and performance on a BCC lattice is approximately the same as that for a cubic lattice with the same number of lattice points. We discuss how the lattice simulations with different geometries can be used to constrain the size lattice artifacts in simulations of continuum quantum many-body systems.

    ↳ cond-mat.quant-gashep-latnucl-thPRC(2021)·2 citations
  4. 09

    Non-Abelian Electric Field Correlator at NLO for Dark Matter Relic Abundance and Quarkonium Transport

    Tobias Binder🇯🇵 · Kyohei Mukaida🇯🇵 · Bruno Scheihing-Hitschfeld🇺🇸 · Xiaojun Yao🇺🇸

    We perform a complete next-to-leading order calculation of the non-Abelian electric field correlator in a SU() plasma, which encodes properties of the plasma relevant for heavy particle bound state formation and dissociation, and is different from the correlator for the heavy quark diffusion coefficient. The calculation is carried out in the real-time formalism of thermal field theory and includes both vacuum and finite temperature contributions. By working in the gauge, we explicitly show the results are gauge independent, infrared and collinear safe. The renormalization group equation of this electric field correlator is determined by that of the strong coupling constant. Our next-to-leading order calculation can be directly applied to any dipole singlet-adjoint transition of heavy particle pairs. For example, it can be used to describe dissociation and (re)generation of heavy quarkonia inside the quark-gluon plasma well below the melting temperature, as well as heavy dark matter pairs (or charged co-annihilating partners) in the early universe.

    ↳ hep-phastro-ph.COnucl-thJHEP(2022)·56 citations
  5. 10

    Three-body dynamics of the resonance from lattice QCD

    Maxim Mai🇺🇸 · Andrei Alexandru🇺🇸 · Ruairí Brett🇺🇸 · Chris Culver🇬🇧 · Michael Döring🇺🇸 · Frank X. Lee🇺🇸 · Daniel Sadasivan🇺🇸

    Resonant hadronic systems often exhibit a complicated decay pattern in which three-body dynamics play a relevant or even dominant role. In this work we focus on the resonance. For the first time, the pole position and branching ratios of a three-body resonance are calculated from lattice QCD using one-, two-, and three-meson interpolators and a three-body finite-volume formalism extended to spin and coupled channels. This marks a new milestone for ab-initio studies of ordinary resonances along with hybrid and exotic hadrons involving three-body dynamics.

    ↳ hep-lathep-phnucl-thPRL(2021)·78 citations

Affiliations

first authorsco-authorsvia INSPIRE