Nuclear Theory·nucl-th

Tuesday·June 26, 2018

17 papers—10 primary·7 cross-listed

11
Modeling the nonperturbative contributions to the complex heavy-quark potential
Yun Guo🇨🇳 · Lihua Dong🇨🇳 · Jisi Pan🇨🇳 · Manoel R. Moldes🇪🇸
In this paper, we construct a simple model for the complex heavy quark potential which is defined through the Fourier transform of the static gluon propagator. Besides the hard thermal loop resummed contribution, the gluon propagator also includes a non-perturbative term induced by the dimension two gluon condensate. Within the framework of thermal field theory, the real and imaginary parts of the heavy quark potential are determined in a consistent way without resorting to any extra assumption as long as the exact form of the retarded/advanced gluon propagator is specified. The resulting potential model has the desired asymptotic behaviors and reproduces the data from lattice simulation reasonably well. By presenting a direct comparison with other complex potential models on the market, we find the one proposed in this work shows a significant improvement on the description of the lattice results, especially for the imaginary part of the potential, in a temperature region relevant to quarkonium studies.
↳ hep-phnucl-thPRD(2019)·38 citations
12
In-medium loop corrections and longitudinally polarized gauge bosons in high-energy showers
Peter Arnold🇺🇸 · Shahin Iqbal🇵🇰
The splitting processes of bremsstrahlung and pair production in a medium are coherent over large distances in the very high energy limit, which leads to a suppression known as the Landau-Pomeranchuk-Migdal (LPM) effect. We continue study of the case when the coherence lengths of two consecutive splitting processes overlap (which is important for understanding corrections to standard treatments of the LPM effect in QCD), avoiding soft-emission approximations. In this particular paper, we show (i) how the "instantaneous" interactions of Light-Cone Perturbation Theory must be included in the calculation to account for effects of longitudinally-polarized gauge bosons in intermediate states, and (ii) how to compute virtual corrections to LPM emission rates, which will be necessary in order to make infrared-safe calculations of the characteristics of in-medium QCD showering of high-energy partons. In order to develop these topics in as simple a context as possible, we will focus in the current paper not on QCD but on large- $N_{f}$ QED, where $N_{f}$ is the number of electron flavors.
↳ hep-phnucl-thJHEP(2018)·22 citations
13
From Nuclei to the Cosmos: Tracing Heavy-Element Production with the Oldest Stars
Anna Frebel (MIT)🇺🇸
Understanding the origin of the elements has been a decades long pursuit, with many open questions still remaining. Old stars found in the Milky Way and its dwarf satellite galaxies can provide answers because they preserve clean elemental patterns of the nucleosynthesis processes that operated some 13 billion years ago. This enables the reconstruction of the chemical evolution of the elements. Here we focus on the astrophysical signatures of heavy neutron-capture elements made in the s-, i- and r-process found in old stars. A highlight is the recently discovered r-process galaxy Reticulum II that was apparently enriched by a neutron star merger. These results show that old stars in dwarf galaxies provide a novel means to constrain the astrophysical site of the r-process, ushering in much needed progress on this major outstanding question. This nuclear astrophysics work complements the many nuclear physics efforts into heavy-element formation, and aligns with recent results on the gravitational wave signature of a neutron star merger.
↳ astro-ph.SRnucl-exnucl-thAnn.Rev.Nucl.Part.Sci.(2018)·73 citations
14
Flavor-dependent EMC effect from a nucleon swelling model
Rong Wang🇫🇷 · Raphaël Dupre🇫🇷 · Yin Huang🇨🇳 · Baiyang Zhang🇭🇺 · Silvia Niccolai🇫🇷
We present our results for a flavor-dependent EMC effect based on the nIMParton nuclear PDFs, in which the $x$ -dependence is described with a nucleon swelling model. The nuclear correction from nucleon swelling is considered through a modification of the initial valence quark distributions instead of a dynamical rescaling. To probe the flavor-dependence of the model, the experimental observables are calculated applying nIMParton nuclear modifications for various experiments: parity-violating deep inelastic scattering on nuclear target, pion-induced Drell-Yan, and W-boson production in proton-nucleus collisions. In addition, we present the expected effect for the spectator-tagged deep inelastic scattering process, which will be performed by the CLAS12 collaboration with the ALERT detector.
↳ hep-phnucl-thPRC(2019)·11 citations
15
Deuteron and Antideuteron Production Simulation in Cosmic-ray Interactions
Diego-Mauricio Gomez-Coral🇲🇽 · Arturo Menchaca Rocha🇲🇽 · Varlen Grabski🇲🇽 · Amaresh Datta🇺🇸 · Philip von Doetinchem🇺🇸 · Anirvan Shukla🇺🇸
The study of the cosmic-ray deuteron and antideuteron flux receives an increasing interest in current astrophysics investigations. For both cases an important contribution is expected from the nuclear interactions of primary cosmic rays with intergalactic matter. In this work, deuteron and antideuteron production from 20 to 2.6 $\times$ 10 $^{7}$ GeV beam energy in p+p and p+A collisions were simulated using EPOS-LHC and Geant4's FTFP-BERT Monte Carlo models by adding an event-by-event coalescence model afterburner. These estimates depend on a single parameter ( $p_{0}$ ) obtained from a fit to the data. The $p_{0}$ for deuterons in this wide energy range was evaluated for the first time. It was found that $p_{0}$ for antideuterons is not a constant at all energies as previous works suggested and as a consequence the antideuteron production cross section can be at least 20 times smaller in the low collision energy region, than earlier estimations.
↳ astro-ph.HEhep-phnucl-thPRD(2018)·38 citations
16
Weak pion production off the nucleon in covariant chiral perturbation theory
De-Liang Yao🇪🇸 · Luis Alvarez-Ruso🇪🇸 · Astrid N. Hiller Blin🇩🇪 · M. J. Vicente Vacas🇪🇸
Weak pion production off the nucleon at low energies has been systematically investigated in manifestly relativistic baryon chiral perturbation theory with explicit inclusion of the $Δ$ (1232) resonance. Most of the involved low-energy constants have been previously determined in other processes such as pion-nucleon elastic scattering and electromagnetic pion production off the nucleon. For numerical estimates, the few remaining constants are set to be of natural size. As a result, the total cross sections for single pion production on neutrons and protons, induced either by neutrino or antineutrino, are predicted. Our results are consistent with the scarce existing experimental data except in the $ν_{μ} n \to μ^{-} n π^{+}$ channel, where higher-order contributions might still be significant. The $Δ$ resonance mechanisms lead to sizeable contributions in all channels, especially in $ν_{μ} p \to μ^{-} p π^{+}$ , even though the considered energies are close to the production threshold. The present study provides a well founded low-energy benchmark for phenomenological models aimed at the description of weak pion production processes in the broad kinematic range of interest for current and future neutrino-oscillation experiments.
↳ hep-phnucl-thPRD(2018)·36 citations
17
Multi-body correlations in SU(3) Fermi gases
Hiroyuki Tajima · Pascal Naidon
We investigate strong-coupling effects in a three-component atomic Fermi gas. It is a promising candidate for simulating quantum chromodynamics (QCD), and furthermore, the emergence of various phenomena such as color superfluidity and Efimov effect are anticipated in this system. In this paper, we study the effects of two-body and three-body correlations by means of the many-body $T$ -matrix approximation (TMA) as well as the Skorniakov-Ter-Martirosian (STM) equation with medium corrections. We investigate the effects of finite temperature and chemical potential on the trimer binding energy at the superfluid critical point of the unitarity limit.
↳ cond-mat.quant-gashep-phnucl-thJ.Low Temp.Phys.(2019)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE

Modeling the nonperturbative contributions to the complex heavy-quark potential

In-medium loop corrections and longitudinally polarized gauge bosons in high-energy showers

From Nuclei to the Cosmos: Tracing Heavy-Element Production with the Oldest Stars

Flavor-dependent EMC effect from a nucleon swelling model

Deuteron and Antideuteron Production Simulation in Cosmic-ray Interactions

Weak pion production off the nucleon in covariant chiral perturbation theory

Multi-body correlations in SU(3) Fermi gases

Affiliations