Nuclear Theory·nucl-th

Thursday·December 1, 2022

12 papers—5 primary·7 cross-listed

06
[Submitted on 29 Nov 2022] (cross-list from hep-ph)
Freezing-In Gravitational Waves
Jacopo Ghiglieri🇫🇷 · Jan Schütte-Engel🇺🇸 · Enrico Speranza🇺🇸
The thermal plasma in the early universe produced a stochastic gravitational wave (GW) background, which peaks today in the microwave regime and was dubbed the cosmic gravitational microwave background (CGMB). In previous works only single graviton production processes that contribute to the CGMB have been considered. Here we also investigate graviton pair production processes and show that these can lead to a significant contribution if the ratio between the maximum temperature and the Planck mass, $T_{max} / m_{p}$ , divided by the internal coupling in the heat bath is large enough. As the dark matter freeze-in production mechanism is conceptually very similar to the GW production mechanism from the primordial thermal plasma, we refer to the latter as ``GW freeze-in production''. We show that quantum gravity effects appear in single graviton production and are smaller by a factor $(T_{max} / m_{p})^{2}$ than the leading order contribution. In our work we explicitly compute the CGMB spectrum within a scalar model with quartic interaction.
Comments:
18 pages, 6 figures (matches version published in Phys. Rev. D)
Subjects:
High Energy Physics — Phenomenology (hep-ph); Cosmology and Nongalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2211.16513 [pdf]
PRD(2024)·58 citations
07
[Submitted on 29 Nov 2022] (cross-list from hep-ph)
Strong two-meson decays of light and charmed vector mesons
Roberto Correa da Silveira🇧🇷 · Fernando E. Serna🇧🇷 · Bruno El-Bennich🇧🇷
We calculate the strong decay couplings for $ρ \to π π$ , $ϕ \to K K$ , $K^{*} \to K π$ and $D^{*} \to D π$ in a unified and consistent approach based on the impulse approximation, nonperturbative solutions of the quark-gap equation and the Poincaré invariant Bethe-Salpeter amplitudes of vector and pseudoscalar mesons. In particular, we obtain the coupling $g_{D^{*} D π} = 17.2 4_{- 2.30}^{+ 3.06}$ in very good agreement with the experimental value by CLEO, which corresponds to a strong effective coupling between heavy vector and pseudoscalar mesons to the pion of $g^= 0.5 8_{- 0.08}^{+ 0.10}$ .
Comments:
10 pages, 4 figures and 7 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2211.16618 [pdf]
PRD(2023)·13 citations
08
[Submitted on 30 Nov 2022] (cross-list from nucl-ex)
Dissipative reactions with intermediate-energy beams -- a novel approach to populate complex-structure states in rare isotopes
A. Gade · B. A. Brown · D. Weisshaar · D. Bazin · K. W. Brown · R. J. Charity · P. Farris · A. M. Hill · J. Li · B. Longfellow · D. Rhodes · W. Reviol · J. A. Tostevin
A novel pathway for the formation of multi-particle-multi-hole (np-mh) excited states in rare isotopes is reported from highly energy- and momentum-dissipative inelastic-scattering events measured in reactions of an intermediate-energy beam of 38Ca on a Be target. The negative-parity,complex-structure final states in 38Ca were observed following the in-beam gamma-ray spectroscopy of events in the 9Be(38Ca,38Ca+gamma)X reaction in which the scattered projectile lost longitudinal momentum of order p = 700 MeV/c. The characteristics of the observed final states are discussed and found to be consistent with the formation of excited states involving the rearrangement of multiple nucleons in a single, highly-energetic projectile-target collision. Unlike the far-less dissipative, surface-grazing reactions usually exploited for the in-beam gamma-ray spectroscopy of rare isotopes, these more energetic collisions appear to offer a practical pathway to nuclear-structure studies of more complex multi-particle configurations in rare isotopes - final states conventionally thought to be out of reach with high-luminosity fast-beam-induced reactions.
Comments:
Accepted in Phys Rev Lett. arXiv admin note: text overlap with arXiv:2210.01106
Subjects:
Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2211.16781 [pdf]
PRL(2022)·11 citations
09
[Submitted on 30 Nov 2022] (cross-list from hep-ph)
Contribution of the Weinberg-type operator to atomic electric dipole moments
Naohiro Osamura🇯🇵
We report the calculation of the isovector CP-odd $π N$ interaction generated by the Weinberg operator, the CP violating three-gluon operator. This enables to restrict models which induce the operator by using experimental data of atomic electric dipole moment. The QCD sum rules are used to determine the matrix element required to assess the CP-odd $π N$ interactions. The relation between the Weinberg operator and the Hg and Xe EDMs is clarified, and the constraint on the Weinberg operator is obtained using the experimental data for the Hg EDM.
Comments:
4 pages, 2 figures, proceedings of the 18th International Conference of Computational Methods in Sciences and Engineering (ICCMSE 2022), Crete, Greece, October 2022
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
arXiv:
2211.16890 [pdf]
AIP Conf.Proc.(2024)·0 citations
10
[Submitted on 30 Nov 2022] (cross-list from hep-lat)
Progress in calculation of the fourth Mellin moment of the pion light-cone distribution amplitude using the HOPE method
William Detmold🇺🇸 · Anthony V. Grebe🇺🇸 · Issaku Kanamori🇯🇵 · C.-J. David Lin🇹🇼 · Robert J. Perry🇹🇼 · Yong Zhao🇺🇸
The pion light-cone distribution amplitude (LCDA) is a central non-perturbative object of interest for the calculation of high-energy exclusive processes in quantum chromodynamics. This article describes the progress in the lattice QCD calculation of the fourth Mellin moment of the pion LCDA using a heavy-quark operator product expansion (HOPE).
Comments:
10 pages, 3 figures, contribution to the proceedings of the 39th International Symposium on Lattice Field Theory (LATTICE2022), 8th-13th August 2022, Bonn, Germany
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2211.17009 [pdf]
PoS(2023)·2 citations
11
[Submitted on 30 Nov 2022] (cross-list from hep-ph)
Chiral perturbation theory
Stefan Scherer🇩🇪 · Matthias R. Schindler🇺🇸
Chiral perturbation theory (ChPT) is an effective field theory that describes the properties of strongly-interacting systems at energies far below typical hadron masses. The degrees of freedom are hadrons instead of the underlying quarks and gluons. ChPT is a systematic and model-independent approximation method based on an expansion of amplitudes in terms of light-quark masses and momenta. The following is a brief overview of ChPT that is largely based on Scherer, Schindler, Lect. Notes Phys. 830 (2012), which can be referred to for a more detailed introduction.
Comments:
contribution to the review "50 Years of Quantum Chromodynamics," edited by F. Gross and E. Klempt [arXiv:2212.11107], to be published in EPJC
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2211.17031 [pdf]
2 citations
12
[Submitted on 30 Nov 2022] (cross-list from hep-ph)
The baryon coupling scheme in an unified SU(3) and SU(6) symmetry formalism
Luiz L. Lopes🇧🇷 · Kauan D. Marquez🇧🇷 · Débora P. Menezes🇧🇷
We calculate the baryon-meson coupling constants for the spin-1/2 baryonic octet and spin-3/2 decuplet in a unified approach relying on symmetry arguments such as the fact that the Yukawa couplings, present in the Lagrangian density of the Walecka-type models, must be an invariant under SU(3) and SU(6) group transformations. The coupling constants of the baryon with the scalar $σ$ meson are fixed to reproduce the known potential depths for the hyperons and $Δ$ resonances, in an approach that can be extended to all particles. We then apply the calculated coupling constants to study neutron star matter with hyperons and deltas admixed to its composition. We conclude that the $Δ^{-}$ is by far the most important exotic particle that can be present in the neutron star interior. It is always present, independent of the chosen parameterization, and might appear in almost every known neutron star, once its onset happens at very low density. Yet, its presence affects the astrophysical properties of the canonical 1.4 M $_{⊙}$ star, and, in some cases, it can even contribute to an increase in the maximum mass reached.
Comments:
16 pages, 11 figures, 5 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
2211.17153 [pdf]
PRD(2023)·33 citations

Affiliations

first authorsco-authorsvia INSPIRE

Freezing-In Gravitational Waves

Strong two-meson decays of light and charmed vector mesons

Dissipative reactions with intermediate-energy beams -- a novel approach to populate complex-structure states in rare isotopes

Contribution of the Weinberg-type operator to atomic electric dipole moments

Progress in calculation of the fourth Mellin moment of the pion light-cone distribution amplitude using the HOPE method

Chiral perturbation theory

The baryon coupling scheme in an unified SU(3) and SU(6) symmetry formalism

Affiliations