Nuclear Theory·nucl-th

Monday·February 28, 2022

10 papers—3 primary·7 cross-listed

04
[Submitted on 24 Feb 2022] (cross-list from hep-ph)
Gauge dependence of the quark gap equation: an exploratory study
José Roberto Lessa🇧🇷 · Fernando E. Serna🇧🇷 · Bruno El-Bennich🇧🇷 · Adnan Bashir🇲🇽 · Orlando Oliveira🇵🇹
We study the gauge dependence of the quark propagator in quantum chromodynamics by solving the gap equation with a nonperturbative quark-gluon vertex which is constrained by longitudinal and transverse Slavnov-Taylor identities, the discrete charge conjugation and parity symmetries and which is free of kinematic singularities in the limit of equal incoming and outgoing quark momenta. We employ gluon propagators in renormalizable $R_{ξ}$ gauges obtained in lattice QCD studies. We report the dependence of the nonperturbative quark propagator on the gauge parameter, in particular we observe an increase, proportional to the gauge-fixing parameter, of the mass function in the infrared domain, whereas the wave renormalization decreases within the range $0 \leq ξ \leq 1$ considered here. The chiral quark condensate reveals a mild gauge dependence in the region of $ξ$ investigated. We comment on how to build and improve upon this exploratory study in future in conjunction with generalized gauge covariance relations for QCD.
Comments:
8 pages, 5 figures, 1 table, version accepted for publication in PRD
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2202.12313 [pdf]
PRD(2023)·20 citations
05
[Submitted on 24 Feb 2022] (cross-list from quant-ph)
Basic Elements for Simulations of Standard Model Physics with Quantum Annealers: Multigrid and Clock States
Marc Illa🇺🇸 · Martin J. Savage🇺🇸
We explore the potential of D-Wave's quantum annealers for computing some of the basic components required for quantum simulations of Standard Model physics. By implementing a basic multigrid (including "zooming") and specializing Feynman-clock algorithms, D-Wave's Advantage is used to study harmonic and anharmonic oscillators relevant for lattice scalar field theories and effective field theories, the time evolution of a single plaquette of SU(3) Yang-Mills lattice gauge field theory, and the dynamics of flavor entanglement in four neutrino systems.
Comments:
27 pages + Supplemental Material, 13 figures, 11 tables; improved Section III B; Published version
Subjects:
Quantum Physics (quant-ph); High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2202.12340 [pdf]
PRA(2022)·73 citations
06
[Submitted on 25 Feb 2022] (cross-list from cond-mat.other)
Friedel formula and Krein's theorem in complex potential scattering theory
Peng Guo🇺🇸 · Vladimir Gasparian🇺🇸
In this work, the generalization of Friedel formula and Krein's theorem in complex potential scattering theory is presented. The consequence of various symmetry constraints on dynamical system are discussed. In addition, Muskhelishvili-Omnès representation of Krein's theorem is also given and discussed.
Subjects:
cond-mat.other (cond-mat.other); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2202.12465 [pdf]
PRResearch(2022)·14 citations
07
[Submitted on 25 Feb 2022] (cross-list from hep-lat)
Nuclear force with LapH smearing
Takuya Sugiura🇯🇵 · Yutaro Akahoshi🇯🇵 · Tatsumi Aoyama🇯🇵 · Takahiro M. Doi🇯🇵 · Takumi Doi🇯🇵
The nuclear forces are determined by combining the HAL QCD method and a new type of source smearing technique. The new smearing is a projection to a space spanned by the lowest-lying eigenvectors of the free Laplacian operator on a lattice, which enables efficient calculation of hadron correlators at an affordable cost by utilizing the hadron-level momentum conservations. We find that this new approach reduces the statistical and systematic errors in the resultant nuclear forces.
Comments:
7 pages, 6 figures
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2202.12532 [pdf]
PoS(2022)·2 citations
08
[Submitted on 25 Feb 2022] (cross-list from physics.atom-ph)
Four-body system of $^{4} He$ atoms: Dimer-dimer scattering
A. Deltuva
The strong short-range repulsion, characteristic to realistic interatomic potentials, complicates the description of weakly-bound few-body systems such as those of \He atoms. The present work proposes an approach for solving this problem and applies it to a realistic system of four $^{4} He$ atoms. The potential is gradually softened such that rigorous four-body equations for bound and scattering tates can be accurately solved in the momentum-space framework, and the results are extrapolated back to the limit of the original potential. Linear correlations between three- and four body quantities are observed, and the accuracy of the procedure is improved by extrapolating in one of the three-body quantities. Results for the $^{4} He$ tetramer ground and excited state binding energies and atom-trimer scattering agree well with at least some of earlier determinations and shed light on the existing disagreements. An additional case of the Phillips correlation line is established for the dimer-dimer scattering length. The trimer production rate via the ultracold two-dimer collisions is estimated, it exhibits significant finite-range effects despite the weak binding of the dimer.
Comments:
6+ pages, 4 figures
Subjects:
Atomic Physics (physics.atom-ph); Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th)
arXiv:
2202.12629 [pdf]
PRA(2022)·3 citations
09
[Submitted on 25 Feb 2022] (cross-list from nucl-ex)
In-beam $γ$ -ray spectroscopy of $^{32}$ Mg via direct reactions
N. Kitamura🇯🇵 · K. Wimmer🇪🇸 · T. Miyagi🇨🇦 · A. Poves🇪🇸 · N. Shimizu🇯🇵 · J. A. Tostevin🇬🇧 · V. M. Bader🇺🇸 · C. Bancroft🇺🇸 · D. Barofsky🇺🇸 · T. Baugher🇺🇸 · D. Bazin🇺🇸 · J. S. Berryman🇺🇸 and 17 other authors
Background: The nucleus $^{32}$ Mg ( $N = 20$ and $Z = 12$ ) plays a central role in the so-called "island of inversion" where in the ground states $s d$ -shell neutrons are promoted to the $f p$ -shell orbitals across the shell gap, resulting in the disappearance of the canonical neutron magic number $N = 20$ . Purpose: The primary goals of this work are to extend the level scheme of $^{32}$ Mg, provide spin-parity assignments to excited states, and discuss the microscopic structure of each state through comparisons with theoretical calculations. Method: In-beam $γ$ -ray spectroscopy of $^{32}$ Mg was performed using two direct-reaction probes, one-neutron (two-proton) knockout reactions on $^{33}$ Mg ( $^{34}$ Si). Final-state exclusive cross sections and parallel momentum distributions were extracted from the experimental data and compared with eikonal-based reaction model calculations combined with shell-model overlap functions. Results: Owing to the remarkable selectivity of the one-neutron and two-proton knockout reactions, a significantly updated level scheme for $^{32}$ Mg, which exhibits negative-parity intruder and positive-parity normal states, was constructed. The experimental results were confronted with four different nuclear structure models. Conclusions: In some of these models, different aspects of $^{32}$ Mg and the transition into the island of inversion are well described. However, unexplained discrepancies remain, and even with the help of these state-of-the-art theoretical approaches, the structure of this key nucleus is not yet fully captured.
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2202.12820 [pdf]
PRC(2022)·7 citations
10
[Submitted on 25 Feb 2022] (cross-list from hep-th)
Neutron stars and phase diagram in a hard-wall AdS/QCD model
Lorenzo Bartolini🇨🇳 · Sven Bjarke Gudnason🇨🇳 · Josef Leutgeb🇦🇹 · Anton Rebhan🇦🇹
We study the phase diagram of (large- $N_{c}$ ) QCD using a simplistic holographic hard-wall model with a dynamical scalar field and a homogeneous Ansatz representing a smeared instanton/baryon density. The resulting phase diagram is qualitatively consistent with expectations, including a mesonic, baryonic, quarkyonic, and quark-gluon plasma phase. As in other holographic models, we also find a baryonic popcorn transition, which appears at large chemical potential as a crossover. We then evaluate the nuclear matter equation of state, which turns out to be rather stiff with a large peaked sound velocity above the conformal limit, construct corresponding neutron stars using the TOV equations, and finally use a full numerical gravity/hydrodynamics computation to extract the gravitational wave signal of neutron star mergers.
Comments:
LaTeX: 45 pages, 12 figures; V2: references and further details added; V3: comments added and typos corrected
Subjects:
High Energy Physics — Theory (hep-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2202.12845 [pdf]
PRD(2022)·32 citations

Affiliations

first authorsco-authorsvia INSPIRE

Gauge dependence of the quark gap equation: an exploratory study

Basic Elements for Simulations of Standard Model Physics with Quantum Annealers: Multigrid and Clock States

Friedel formula and Krein's theorem in complex potential scattering theory

Nuclear force with LapH smearing

Four-body system of 4He atoms: Dimer-dimer scattering

In-beam γ-ray spectroscopy of 32Mg via direct reactions

Neutron stars and phase diagram in a hard-wall AdS/QCD model

Affiliations

Four-body system of $^{4} He$ atoms: Dimer-dimer scattering

In-beam $γ$ -ray spectroscopy of $^{32}$ Mg via direct reactions