Nuclear Theory·nucl-th

Thursday·May 4, 2023

7 papers—4 primary·3 cross-listed

05
[Submitted on 2 May 2023] (cross-list from hep-ph)
Baryons, multi-hadron systems, and composite dark matter in non-relativistic QCD
Benoît Assi🇺🇸 · Michael L. Wagman🇺🇸
We provide a formulation of potential non-relativistic quantum chromodynamics (pNRQCD) suitable for calculating binding energies and matrix elements of generic hadron and multi-hadron states made of heavy quarks in $S U (N_{c})$ gauge theory using quantum Monte Carlo techniques. We compute masses of quarkonium and triply-heavy baryons in order to study the perturbative convergence of pNRQCD and validate our numerical methods. Further, we study $S U (N_{c})$ models of composite dark matter and provide simple power series fits to our pNRQCD results that can be used to relate dark meson and baryon masses to the fundamental parameters of these models. For many systems comprised entirely of heavy quarks, the quantum Monte Carlo methods employed here are less computationally demanding than lattice field theory methods, although they introduce additional perturbative approximations. The formalism presented here may therefore be particularly useful for predicting composite dark matter properties for a wide range of $N_{c}$ and heavy fermion masses.
Comments:
39 pages, 24 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2305.01685 [pdf]
PRD(2023)·14 citations
06
[Submitted on 3 May 2023] (cross-list from hep-ph)
$Σ$ Resonances from a Neural Network-based Partial Wave Analysis on $K^{-} p$ Scattering
Jun Shi🇨🇳 · Long-Cheng Gui🇨🇳 · Jian Liang🇨🇳 · Guoming Liu🇨🇳
We implement a convolutional neural network to study the $Σ$ hyperons using experimental data of the $K^{-} p \to π^{0} Λ$ reaction. The averaged accuracy of the NN models in resolving resonances on the test data sets is $98.5%$ , $94.8%$ and $82.5%$ for one-, two- and three-additional-resonance case. We find that the three most significant resonances are $1/ 2^{+}$ , $3/ 2^{+}$ and $3/ 2^{-}$ states with mass being $1.62 (11) GeV$ , $1.72 (6) GeV$ and $1.61 (9) GeV$ , and probability being $100 (3) %$ , $72 (24) %$ and $98 (52) %$ , respectively, where the errors mostly come from the uncertainties of the experimental data. Our results support the three-star $Σ (1660) 1/ 2^{+}$ , the one-star $Σ (1780) 3/ 2^{+}$ and the one-star $Σ (1580) 3/ 2^{-}$ in PDG. The ability of giving quantitative probabilities in resonance resolving and numerical stability make NN potentially a life-changing tool in baryon partial wave analysis, and this approach can be easily extended to accommodate other theoretical models and/or to include more experimental data.
Comments:
6 pages, 6 figures with supplemental materials
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2305.01852 [pdf]
1 citation
07
[Submitted on 3 May 2023] (cross-list from hep-ph)
Sea contribution to the charge radii and quadrupole moment of $J^{P} = \frac{1}{2}^{+}, \frac{3}{2}^{+}$ baryons
Preeti Bhall🇮🇳 · Meenakshi Batra🇮🇳 · Alka Upadhyay🇮🇳
An operator formalism is used on the wavefunction of baryons to compute their charge radii and quadrupole moments. Total anti-symmetric wavefunction in spin, color and flavor space is framed for $J^{P} = \frac{1}{2}^{+}$ nucleons and $J^{P} = \frac{3}{2}^{+}$ hyperons. To understand the importance of sea, statistical model is used in conjugation with the detailed balance principle. Within the statistical approach, the importance of sea with quarks and gluons are studied using the relevant probabilities that are associated with spin, flavor, and color space. The present work also focuses on individual contributions of valence and sea which contains terms of scalar, vector and tensor sea. The obtained results are in agreement with available theories and few experimental outcomes. Our computed results may provide important information for upcoming experimental findings.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2305.01894 [pdf]
PTEP(2023)·4 citations

Affiliations

first authorsco-authorsvia INSPIRE

Baryons, multi-hadron systems, and composite dark matter in non-relativistic QCD

Σ Resonances from a Neural Network-based Partial Wave Analysis on K−p Scattering

Sea contribution to the charge radii and quadrupole moment of JP=21​+,23​+ baryons

Affiliations

$Σ$ Resonances from a Neural Network-based Partial Wave Analysis on $K^{-} p$ Scattering

Sea contribution to the charge radii and quadrupole moment of $J^{P} = \frac{1}{2}^{+}, \frac{3}{2}^{+}$ baryons