Nuclear Theory·nucl-th

Wednesday·June 17, 2020

13 papers—4 primary·9 cross-listed

05
[Submitted on 13 Jun 2020] (cross-list from hep-ph)
Neutrino (Antineutrino)-Nucleus Interactions in the Shallow- and Deep-Inelastic Scattering Regions
M. Sajjad Athar🇮🇳 · Jorge G. Morfin🇺🇸
In $ν / ν ˉ$ -N/A interactions SIS is technically defined in terms of the four-momentum transfer to the hadronic system as non-resonant meson production with $Q^{2} ⪅ 1 G e V^{2}$ . This non-resonant meson production intermixes with resonant meson production in a regime of similar effective hadronic mass W of the interaction. As $Q^{2}$ grows and surpasses this $\approx 1 G e V^{2}$ limit, non-resonant interactions begin to take place with quarks within the nucleon indicating the start of DIS region. SIS and DIS regions have received varying degrees of attention from the community. While the theoretical / phenomenological study of $ν$ -nucleon and $ν$ -nucleus DIS scattering is advanced, such studies of a large portion of the SIS region, particularly the SIS to DIS transition region, have hardly begun. Experimentally, the SIS and the DIS regions for $ν$ -nucleon scattering have minimal results and only in the experimental study of the $ν$ -nucleus DIS region are there significant results for some nuclei. Since current and future neutrino oscillation experiments have contributions from both higher W SIS and DIS kinematic regions and these regions are in need of both considerable theoretical and experimental study, this review will concentrate on these SIS to DIS transition and DIS kinematic regions surveying our knowledge and the current challenges.
Comments:
110 pages, 58 figures, Invited Review Article in Journal of Physics G: Nuclear and Particle Physics - IOPscience (Accepted for Publication)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2006.08603 [pdf]
J.Phys.G(2021)·70 citations
06
[Submitted on 15 Jun 2020] (cross-list from hep-ph)
Determining the nuclear neutron distribution from Coherent Elastic neutrino-Nucleus Scattering: current results and future prospects
Pilar Coloma🇪🇸 · Ivan Esteban🇪🇸 · M.C. Gonzalez-Garcia🇪🇸 · Javier Menendez🇪🇸
Coherent elastic neutrino-nucleus scattering (CE $ν$ NS), a process recently measured for the first time at ORNL's Spallation Neutron Source, is directly sensitive to the weak form factor of the nucleus. The European Spallation Source (ESS), presently under construction, will generate the most intense pulsed neutrino flux suitable for the detection of CE $ν$ NS. In this paper we quantify its potential to determine the root mean square radius of the point-neutron distribution, for a variety of target nuclei and a suite of detectors. To put our results in context we also derive, for the first time, a constraint on this parameter from the analysis of the energy and timing data of the CsI detector at the COHERENT experiment.
Comments:
16 pages, 4 figures. Minor text changes and references added. Matches version accepted by JHEP
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2006.08624 [pdf]
JHEP(2020)·53 citations
07
[Submitted on 15 Jun 2020] (cross-list from hep-ph)
Forward doubly-virtual Compton scattering off the nucleon in chiral perturbation theory: II. Spin polarizabilities and moments of polarized structure functions
Jose Manuel Alarcón (U. Complutense de Madrid & IPARCOS)🇪🇸 · Franziska Hagelstein (AEC Bern)🇨🇭 · Vadim Lensky🇩🇪 · Vladimir Pascalutsa (JGU Mainz)🇩🇪
We examine the polarized doubly-virtual Compton scattering (VVCS) off the nucleon using chiral perturbation theory ( $χ$ PT). The polarized VVCS contains a wealth of information on the spin structure of the nucleon which is relevant to the calculation of the two-photon-exchange effects in atomic spectroscopy and electron scattering. We report on a complete next-to-leading-order (NLO) calculation of the polarized VVCS amplitudes $S_{1} (ν, Q^{2})$ and $S_{2} (ν, Q^{2})$ , and the corresponding polarized spin structure functions $g_{1} (x, Q^{2})$ and $g_{2} (x, Q^{2})$ . Our results for the moments of polarized structure functions, partially related to different spin polarizabilities, are compared to other theoretical predictions and "data-driven" evaluations, as well as to the recent Jefferson Lab measurements. By expanding the results in powers of the inverse nucleon mass, we reproduce the known "heavy-baryon" expressions. This serves as a check of our calculation, as well as demonstrates the differences between the manifestly Lorentz-invariant baryon $χ$ PT (B $χ$ PT) and heavy-baryon (HB $χ$ PT) frameworks.
Comments:
47 pages, 11 figures, 2 tables. Includes Mathematica notebook with the spin polarizabilities and moments of polarized structure functions as supplemental material. Replaced to match the published version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
arXiv:
2006.08626 [pdf]
PRD(2020)·22 citations
08
[Submitted on 15 Jun 2020] (cross-list from hep-ph)
Reflections upon the Emergence of Hadronic Mass
Craig D. Roberts🇨🇳 · Sebastian M. Schmidt🇩🇪
With discovery of the Higgs boson, science has located the source for $≲ 2$ % of the mass of visible matter. The focus of attention can now shift to the search for the origin of the remaining $≳ 98$ %. The instruments at work here must be capable of simultaneously generating the 1 GeV mass-scale associated with the nucleon and ensuring that this mass-scale is completely hidden in the chiral-limit pion. This hunt for an understanding of the emergence of hadronic mass (EHM) has actually been underway for many years. What is changing are the impacts of QCD-related theory, through the elucidation of clear signals for EHM in hadron observables, and the ability of modern and planned experimental facilities to access these observables. These developments are exemplified in a discussion of the evolving understanding of pion and kaon parton distributions.
Comments:
13 pages, 9 figures. Invited contribution to EPJ ST Issue "Strong Correlations in Dense Matter Physics"
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2006.08782 [pdf]
Eur.Phys.J.ST(2020)·62 citations
09
[Submitted on 15 Jun 2020] (cross-list from hep-ph)
Quark spin - thermal vorticity alignment and the Lambda, anti-Lambda polarization in heavy-ion collisions
Alejandro Ayala🇲🇽 · David de la Cruz🇲🇽 · L. A. Hernández🇲🇽 · S. Hernández-Ortíz🇺🇸 · Jordi Salinas🇲🇽
It has been proposed that the $Λ$ and $Λ$ polarizations observed in heavy-ion collisions are due to the interaction between quark spin and thermal vorticity. In this work we report on a computation of the relaxation time required for this alignment to occur at finite temperature and baryon chemical potential, considering quarks with a finite mass. The calculation is performed after modelling the interaction by means of an effective vertex which couples the thermal gluons and quarks within the vortical medium. We show that the effect of the quark mass is to reduce the relaxation time as compared to the massless quark case. An intrinsic global polarization of quarks/antiquarks emerges which is shown to be linked with the $Λ$ / $Λ ˉ$ polarization.
Comments:
9 pages, 5 figures. Proceedings of the 36th Winter Workshop on Nuclear Dynamics, Puerto Vallarta, Mexico 2020
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.08800 [pdf]
J.Phys.Conf.Ser.(2020)·1 citation
10
[Submitted on 16 Jun 2020] (cross-list from cond-mat.quant-gas)
Generating Giant Vortex in a Fermi Superfluid via Spin-Orbital-Angular-Momentum Coupling
Ke-Ji Chen · Fan Wu · Shi-Guo Peng · Wei Yi · Lianyi He
Spin-orbital-angular-momentum (SOAM) coupling has been realized in recent experiments of Bose-Einstein condensates [Chen et al., Phys. Rev. Lett. 121, 113204 (2018) and Zhang et al., Phys. Rev. Lett. 122, 110402 (2019)], where the orbital angular momentum imprinted upon bosons leads to quantized vortices. For fermions, such an exotic synthetic gauge field can provide fertile ground for fascinating pairing schemes and rich superfluid phases, which are yet to be explored. Here we demonstrate how SOAM coupling stabilizes vortices in Fermi superfluids through a unique mechanism that can be viewed as the angular analog to that of the spin-orbit-coupling-induced Fulde-Ferrell state under a Fermi surface deformation. Remarkably, the vortex size is comparable with the beam waist of Raman lasers generating the SOAM coupling, which is typically much larger than previously observed vortices in Fermi superfluids. With tunable size and core structure, these giant vortex states provide unprecedented experimental access to topological defects in Fermi superfluids.
Comments:
6+5 pages, 5+5 figures
Subjects:
Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
arXiv:
2006.08898 [pdf]
PRL(2021)·11 citations
11
[Submitted on 16 Jun 2020] (cross-list from hep-ph)
Modified Excluded Volume Hadron Resonance Gas Model with Lorentz Contraction
Somenath Pal🇮🇳 · Abhijit Bhattacharyya🇮🇳 · Rajarshi Ray🇮🇳
In this work we discuss a modified version of Excluded Volume Hadron Resonance Gas model and also study the effect of Lorentz contraction of the excluded volume on scaled pressure and susceptibilities of conserved charges. We find that the Lorentz contraction, coupled with the variety of excluded volume parameters reproduce the lattice QCD data quite satisfactorily.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.08985 [pdf]
NPA(2021)·8 citations
12
[Submitted on 16 Jun 2020] (cross-list from hep-ph)
Studying $Λ^{*}$ resonances in the $p p ˉ \to Λ Λ ˉ η$ reaction
Bo-Chao Liu🇨🇳 · Ke Wang🇨🇳
In this work, we make a theoretical study on the $p p ˉ \to Λ Λ ˉ η$ reaction for antiproton beam energy from threshold to 4GeV within an effective Lagrangian approach and isobar model. By assuming this reaction is dominated by the excitation of $Λ$ and $Λ ˉ$ resonances in intermediate states, we calculate the total cross sections and give the predictions of the angular distribution and invariant mass spectrum of final particles. In particular, we discuss the possibility to verify the existence of a narrow $Λ$ resonance found in the process of $K^{-} p \to η Λ$ in the present reaction. It shows that the $p p ˉ \to Λ ˉ Λ η$ reaction can provide us with valuable information about the $Λ$ resonances having significant couplings to $K ˉ N$ and $Λ η$ channels. Thus the experimental data of this reaction will be a good supplement to the $K ˉ N \to η Λ$ scattering data for studying $Λ$ resonances.
Comments:
8 pages, 5 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.09195 [pdf]
PRD(2020)·2 citations
13
[Submitted on 16 Jun 2020] (cross-list from hep-ph)
Pseudothermalization of the quark-gluon plasma
Michael Strickland🇺🇸
In this proceedings contribution I review recent work in kinetic theory which demonstrates that, for system undergoing Bjorken expansion, there exists an attractor in all moments of the one-particle distribution function. I discuss how this attractor emerges in both exact solutions obtained in relaxation time approximation (RTA) and the effective kinetic theory approach to high-temperature quantum chromodynamics (QCD). The QCD effective kinetic theory collisional kernel used includes both elastic (2 <-> 2) and LPM-resummed inelastic (2 <-> 1) contributions. The results obtained indicate that a pseudothermal attractor exists in both RTA and QCD kinetic theory and that their respective attractors can be extended to early times when the system is far from equilibrium. Finally, I discuss how knowledge of the QCD effective kinetic theory attractor can be used to assess different hydrodynamic freeze-out prescriptions used in heavy-ion phenomenology. The results obtained show that improved freeze-out prescriptions such as anisotropic hydrodynamics perform better in conditions corresponding to those generated in high-multiplicity pA and pp collisions, e.g. short lifetime and high inverse Reynolds number.
Comments:
9 pages, 4 multipanel figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2006.09284 [pdf]
J.Phys.Conf.Ser.(2020)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE