Nuclear Theory·nucl-th

Friday·August 13, 2021

7 papers—2 primary·5 cross-listed

03
[Submitted on 11 Aug 2021] (cross-list from hep-ph)
Transverse Lambda production at the future Electron-Ion Collider
Zhong-Bo Kang🇺🇸 · John Terry🇺🇸 · Anselm Vossen🇺🇸 · Qinghua Xu🇨🇳 · Jinlong Zhang🇺🇸
We provide a comprehensive overview of transversely polarized $Λ$ production at the future Electron-Ion Collider (EIC). In particular, we study both spontaneous transverse $Λ$ polarization as well as the transverse spin transfer within the Transverse Momentum Dependent (TMD) factorization region. To describe spontaneous $Λ$ polarization, we consider the contribution from the TMD Polarizing Fragmentation Function (TMD PFF). Similarly, we study the contribution of the transverse spin transfer originating from the transversity TMD Fragmentation Function (TMD FF). We provide projections for the statistical uncertainties in the corresponding spin observables at the future EIC. Using these statistical uncertainties, we characterize the role that the future EIC will play in constraining these distributions. We perform an impact study in the semi-inclusive deep inelastic scattering process for spontaneous $Λ$ polarization with a proton beam. We find that the projected experimental data leads to a significant decrease in the uncertainties for the $u$ and sea TMD PFFs. Furthermore, to access the impact of the EIC on the transversity TMD FF, we perform the first extraction of the transversity TMD FF from the recent COMPASS data. We compare the statistical uncertainties of the future EIC with the theoretical uncertainties from our extraction and find that the EIC could have a significant role in constraining this distribution. Finally, we also provide projections for both spontaneous $Λ$ polarization as well as the transverse spin transfer inside the jets in back-to-back electron-jet production at the EIC.
Comments:
19 pages 15 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Theory (hep-th); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2108.05383 [pdf]
PRD(2022)·33 citations
04
[Submitted on 12 Aug 2021] (cross-list from hep-ph)
Magic mixing angles for doubly heavy baryons
Takayuki Matsuki🇯🇵 · Dian-Yong Chen🇨🇳 · Xiang Liu🇨🇳 · Qi-Fang Lü🇨🇳
We study the so-called magic mixing angles for doubly heavy baryons. Defining that a magic mixing angle rotates states with definite $^{2 S + 1} (l_{λ})_{J}$ to make them heavy-quark symmetric states, we derive the magic mixing angle only in the case $L_{ρ} = 0$ between the heavy quark symmetric states with quantum numbers $(J, j_{ℓ})$ and the states with $(J, s_{q} + j_{ρ}) = (J, {^{4} l_{λ} /^{2} l_{λ}})$ for a doubly heavy baryon in the standard $ρ - λ$ configuration, where $j_{ℓ} = l_{λ} + s_{q}$ , $s_{ρ} = s_{Q 1} + s_{Q 2}$ , and $j_{ρ} = s_{ρ} + L_{ρ}$ . We discuss how this mixing angle affects model building for a doubly heavy baryon.
Comments:
6 pages, 1 figure
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2108.05642 [pdf]
Nucl.Phys.Rev.(2021)·2 citations
05
[Submitted on 11 Aug 2021] (cross-list from cond-mat.stat-mech)
Study of invariance of nonextensive statistics under the uniform energy spectrum translation
A.S. Parvan🇷🇺
The general formalisms of the $q$ -dual statistics, the Boltzmann-Gibbs statistics, and three versions of the Tsallis statistics known as Tsallis-1, Tsallis-2, and Tsallis-3 statistics have been considered in the canonical ensemble. We have rigorously proved that the probability distribution of the Tsallis-1 statistics is invariant under the uniform energy spectrum translation at a fixed temperature. This invariance demonstrates that the formalism of the Tsallis-1 statistics is consistent with the fundamentals of the equilibrium statistical mechanics. The same results we have obtained for the probability distributions of the Tsallis-3 statistics, Boltzmann-Gibbs statistics, and $q$ -dual statistics. However, we have found that the probability distribution of the Tsallis-2 statistics, the expectation values of which are not consistent with the normalization condition of probabilities, is indeed not invariant under the overall shift in energy as expected.
Comments:
14 pages
Subjects:
Statistical Mechanics (cond-mat.stat-mech); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2108.05702 [pdf]
Physica A: Statistical Mechanics and its Applications(2022)·5 citations
06
[Submitted on 12 Aug 2021] (cross-list from hep-ph)
Global QCD Analysis of Pion Parton Distributions with Threshold Resummation
P. C. Barry🇺🇸 · Chueng-Ryong Ji🇺🇸 · N. Sato🇺🇸 · W. Melnitchouk🇺🇸
We perform the first global QCD analysis of pion valence, sea quark, and gluon distributions within a Bayesian Monte Carlo framework with threshold resummation on Drell-Yan cross sections at next-to-leading log accuracy. Exploring various treatments of resummation, we find that the large- $x$ asymptotics of the valence quark distribution $\sim (1 - x)^{β_{v}}$ can differ significantly, with $β_{v}$ ranging from $\approx 1$ to $> 2.5$ at the input scale. Regardless of the specific implementation, however, the resummation induced redistribution of the momentum between valence quarks and gluons boosts the total momentum carried by gluons to $\approx 40%$ , increasing the gluon contribution to the pion mass to $\approx 40$ MeV.
Comments:
6 pages, 3 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
arXiv:
2108.05822 [pdf]
PRL(2021)·123 citations
07
[Submitted on 12 Aug 2021] (cross-list from hep-ph)
Relations between strong decay widths of the $P_{c}$ pentaquarks in the SU(4) flavor-spin model
Fl. Stancu🇧🇪
In a previous work we have studied the isospin 1/2 lowest positive and negative parity states of the pentaquark $uu d c c$ , in a constituent quark model with a linear confinement and an SU(4) flavor-spin hyperfine interaction and we compared the results with the $P_{c}^{+} (4312)$ , $P_{c}^{+} (4440)$ and $P_{c}^{+} (4457)$ pentaquarks observed at LHCb in 2019. Here we extend the previous work by calculating ratios of decay rates of the $P_{c}$ pentaquarks to $J /Ψ$ and $η_{c}$ and similarly the ratio of decay rates to $Λ_{c} D ˉ^{*}$ and $Λ_{c} D ˉ$ . Our predictions are based on the SU(4) $\times$ SU(2) structure of compact pentaquarks.
Comments:
16 pages, minor changes, it matches the published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2108.05841 [pdf]
PRD(2021)·9 citations

Affiliations

first authorsco-authorsvia INSPIRE

Transverse Lambda production at the future Electron-Ion Collider

Magic mixing angles for doubly heavy baryons

Study of invariance of nonextensive statistics under the uniform energy spectrum translation

Global QCD Analysis of Pion Parton Distributions with Threshold Resummation

Relations between strong decay widths of the Pc​ pentaquarks in the SU(4) flavor-spin model

Affiliations

Relations between strong decay widths of the $P_{c}$ pentaquarks in the SU(4) flavor-spin model