Nuclear Theory·nucl-th

Tuesday·November 3, 2020

16 papers—8 primary·8 cross-listed

09
[Submitted on 30 Oct 2020] (cross-list from hep-ph)
Deuteron Uncertainties in the Determination of Proton PDFs
Richard D. Ball🇬🇧 · Emanuele R. Nocera🇬🇧 · Rosalyn L. Pearson🇬🇧
We evaluate the uncertainties due to nuclear effects in global fits of proton parton distribution functions (PDFs) that utilise deep-inelastic scattering and Drell-Yan data on deuterium targets. To do this we use an iterative procedure to determine proton and deuteron PDFs simultaneously, each including the uncertainties in the other. We apply this procedure to determine the nuclear uncertainties in the SLAC, BCDMS, NMC and DYE866/NuSea fixed target deuteron data included in the NNPDF3.1 global fit. We show that the effect of the nuclear uncertainty on the proton PDFs is small, and that the increase in overall uncertainties is insignificant once we correct for nuclear effects.
Comments:
Version accepted for publication in Eur. Phys. J. C; typo in Table 3 corrected; discussion about previous NNPDF studies added; various minor points clarified
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2011.00009 [pdf]
EPJC(2021)·41 citations
10
[Submitted on 4 Aug 2020] (cross-list from physics.chem-ph)
Three related topics on the periodic tables of elements
Yoshiteru Maeno · Kouichi Hagino · Takehiko Ishiguro
A large variety of periodic tables of the chemical elements have been proposed. It was Mendeleev who proposed a periodic table based on the extensive periodic law and predicted a number of unknown elements at that time. The periodic table currently used worldwide is of a long form pioneered by Werner in 1905. As the first topic, we describe the work of Pfeiffer (1920), who refined Werner's work and rearranged the rare-earth elements in a separate table below the main table for convenience. Today's widely used periodic table essentially inherits Pfeiffer's arrangements. Although long-form tables more precisely represent electron orbitals around a nucleus, they lose some of the features of Mendeleev's short-form table to express similarities of chemical properties of elements when forming compounds. As the second topic, we compare various three-dimensional helical periodic tables that resolve some of the shortcomings of the long-form periodic tables in this respect. In particular, we explain how the 3D periodic table "Elementouch" (Maeno 2001), which combines the s- and p-blocks into one tube, can recover features of Mendeleev's periodic law. Finally we introduce a topic on the recently proposed nuclear periodic table based on the proton magic numbers (Hagino and Maeno 2020). Here, the nuclear shell structure leads to a new arrangement of the elements with the proton magic-number nuclei treated like noble-gas atoms. We show that the resulting alignments of the elements in both the atomic and nuclear periodic tables are common over about two thirds of the tables because of a fortuitous coincidence in their magic numbers.
Comments:
14 pages. To appear in Foundations of Chemistry
Subjects:
physics.chem-ph (physics.chem-ph); Nuclear Theory (nucl-th)
arXiv:
2011.00060 [pdf]
2 citations
11
[Submitted on 31 Oct 2020] (cross-list from hep-lat)
Conserved charge fluctuations in the chiral limit
Mugdha Sarkar🇩🇪 · Olaf Kaczmarek🇩🇪 · Frithjof Karsch🇩🇪 · Anirban Lahiri🇩🇪 · Christian Schmidt🇩🇪
We study the signs of criticality in conserved charge fluctuations and related observables of finite temperature QCD at vanishing chemical potential, as we approach the chiral limit of two light quarks. Our calculations have been performed on gauge ensembles generated using Highly Improved Staggered Quark (HISQ) fermion action, with pion masses ranging from 140 MeV to 55 MeV.
Comments:
10 pages, 8 figures, Proceedings of workshop on Criticality in QCD and the Hadron Resonance Gas; 29-31 July 2020, Wroclaw, Poland
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2011.00240 [pdf]
Acta Phys.Polon.Supp.(2021)·4 citations
12
[Submitted on 1 Nov 2020] (cross-list from hep-lat)
QCD in the heavy dense regime: Large $N_{c}$ and quarkyonic matter
Owe Philipsen🇩🇪 · Jonas Scheunert🇩🇪
After combined character and hopping expansions and integration over the spatial gauge links, lattice QCD reduces to a three-dimensional $S U (3)$ Polyakov loop model with complicated interactions. A simple truncation of the effective theory is valid for heavy quarks on reasonably fine lattices and can be solved by linked cluster expansion in its effective couplings. This was used ealier to demonstrate the onset transition to baryon matter in the cold and dense regime. Repeating these studies for general $N_{c}$ , one finds that for large $N_{c}$ the onset transition becomes first-order, and the pressure scales as $p \sim N_{c}$ through three consecutive orders in the hoppoing expansion. These features are consistent with the formal definition of quarkyonic matter given in the literature. We discuss the implications for $N_{c} = 3$ and physical QCD.
Comments:
10 pages, 5 figures, contribution to `Criticality in QCD and the hadron resonance gas', Wroclaw, July 29-31, 2020
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2011.00504 [pdf]
Acta Phys.Polon.Supp.(2021)·1 citation
13
[Submitted on 2 Nov 2020] (cross-list from nucl-ex)
Ruling out color transparency in quasi-elastic $^{12}$ C(e,e'p) up to $Q^{2}$ of 14.2 (GeV/c) $^{2}$
D. Bhetuwal🇺🇸 · J. Matter🇺🇸 · H. Szumila-Vance🇺🇸 · M. L. Kabir🇺🇸 · D. Dutta🇺🇸 · R. Ent🇺🇸 · D. Abrams🇺🇸 · Z. Ahmed🇨🇦 · B. Aljawrneh🇺🇸 · S. Alsalmi🇺🇸 · R. Ambrose🇨🇦 · D. Androic🇭🇷 and 78 other authors
Quasielastic $^{12}$ C $(e, e^{'} p)$ scattering was measured at space-like 4-momentum transfer squared $Q^{2}$ ~=~8, 9.4, 11.4, and 14.2 (GeV/c) $^{2}$ , the highest ever achieved to date. Nuclear transparency for this reaction was extracted by comparing the measured yield to that expected from a plane-wave impulse approximation calculation without any final state interactions. The measured transparency was consistent with no $Q^{2}$ dependence, up to proton momenta of 8.5~GeV/c, ruling out the quantum chromodynamics effect of color transparency at the measured $Q^{2}$ scales in exclusive $(e, e^{'} p)$ reactions. These results impose strict constraints on models of color transparency for protons.
Comments:
5 pages, 2 figures
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2011.00703 [pdf]
PRL(2021)·50 citations
14
[Submitted on 2 Nov 2020] (cross-list from hep-ph)
Two-Meson Form Factors in Unitarized Chiral Perturbation Theory
Yu-Ji Shi🇩🇪 · Chien-Yeah Seng🇩🇪 · Feng-Kun Guo🇨🇳 · Bastian Kubis🇩🇪 · Ulf-G. Meißner🇩🇪 · Wei Wang🇨🇳
We present a comprehensive analysis of form factors for two light pseudoscalar mesons induced by scalar, vector, and tensor quark operators. The theoretical framework is based on a combination of unitarized chiral perturbation theory and dispersion relations. The low-energy constants in chiral perturbation theory are fixed by a global fit to the available data of the two-meson scattering phase shifts. Each form factor derived from unitarized chiral perturbation theory is improved by iteratively applying a dispersion relation. This study updates the existing results in the literature and explores those that have not been systematically studied previously, in particular the two-meson tensor form factors within unitarized chiral perturbation theory. We also discuss the applications of these form factors as mandatory inputs for low-energy phenomena, such as the semi-leptonic decays $B_{s} \to π^{+} π^{-} ℓ^{+} ℓ^{-}$ and the $τ$ lepton decay $τ \to π^{-} π^{0} ν_{τ}$ , in searches for physics beyond the Standard Model.
Comments:
53 pages, 21 figures, 3 tables
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2011.00921 [pdf]
JHEP(2021)·20 citations
15
[Submitted on 2 Nov 2020] (cross-list from hep-lat)
Lattice continuum-limit study of nucleon quasi-PDFs
Constantia Alexandrou🇨🇾 · Krzysztof Cichy🇵🇱 · Martha Constantinou🇺🇸 · Jeremy R. Green🇨🇭 · Kyriakos Hadjiyiannakou🇨🇾 · Karl Jansen🇩🇪 · Floriano Manigrasso🇨🇾 · Aurora Scapellato🇵🇱 · Fernanda Steffens🇩🇪
The quasi-PDF approach provides a path to computing parton distribution functions (PDFs) using lattice QCD. This approach requires matrix elements of a power-divergent operator in a nucleon at high momentum and one generically expects discretization effects starting at first order in the lattice spacing $a$ . Therefore, it is important to demonstrate that the continuum limit can be reliably taken and to understand the size and shape of lattice artifacts. In this work, we report a calculation of isovector unpolarized and helicity PDFs using lattice ensembles with $N_{f} = 2 + 1 + 1$ Wilson twisted mass fermions, a pion mass of approximately 370 MeV, and three different lattice spacings. Our results show a significant dependence on $a$ , and the continuum extrapolation produces a better agreement with phenomenology. The latter is particularly true for the antiquark distribution at small momentum fraction $x$ , where the extrapolation changes its sign.
Comments:
24 pages, 21 figures. v2: additional references, discussion of systematics, and position-space comparison with phenomenology. v3: applied workaround for problem affecting Greek symbols in figures with some PDF viewers
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2011.00964 [pdf]
PRD(2021)·71 citations
16
[Submitted on 2 Nov 2020] (cross-list from gr-qc)
Solution to the hyperon puzzle using dark matter
Antonino Del Popolo🇮🇹 · Maksym Deliyergiyev🇵🇱 · Morgan Le Delliou🇨🇳
In this paper, we studied the ``hyperon puzzle", a problem that nevertheless the large number of studies is still an open problem. The solution of this issue requires one or more mechanisms that could eventually provide the additional repulsion needed to make the EoS stiffer and, therefore, the value of $M_{max, T}$ compatible with the current observational limits. In this paper we proposed that including dark matter (DM) admixed with ordinary matter in neutron stars (NSs), change the hydrostatic equilibrium and may explain the observed discrepancies, regardless to hyperon multi-body interactions, which seem to be unavoidable. We have studied how non-self-annihilating, and self-interacting, DM admixed with ordinary matter in NSs changes their inner structure, and discussed the mass-radius relations of such NSs. We considered DM particle masses of 1, 10, and 100 GeV, while taking into account a rich list of the DM interacting strengths, $y$ . By analyzing the multidimensional parameter space, including several quantities like: a. the DM interacting strength, b. the DM particle mass as well as the quantity of DM in its interior, and c. the DM fraction, $f_{D M}$ , we put constraints in the parameter space $f_{D M} - p_{DM}^{'} / p_{OM}^{'}$ . Our bounds are sensitive to the recently observed NSs total masses.
Comments:
12 pp, 6 figs
Subjects:
General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2011.00984 [pdf]
Phys.Dark Univ.(2020)·26 citations

Affiliations

first authorsco-authorsvia INSPIRE