Nuclear Theory·nucl-th

Tuesday·December 24, 2019

20 papers—10 primary·10 cross-listed

11
[Submitted on 20 Dec 2019] (cross-list from hep-ph)
Data-driven study of timelike Compton scattering
O. Grocholski🇵🇱 · H. Moutarde🇫🇷 · B. Pire🇫🇷 · P. Sznajder🇵🇱 · J. Wagner🇵🇱
In the framework of collinear QCD factorization, the leading twist scattering amplitudes for deeply virtual Compton scattering (DVCS) and timelike Compton scattering (TCS) are intimately related thanks to analytic properties of leading and next-to-leading order amplitudes. We exploit this welcome feature to make data-driven predictions for TCS observables to be measured in near future experiments. Using a recent extraction of DVCS Compton form factors from most of the existing experimental data for that process, we derive TCS amplitudes and calculate TCS observables only assuming leading-twist dominance. Artificial neural network techniques are used for an essential reduction of model dependency, while a careful propagation of experimental uncertainties is achieved with replica methods. Our analysis allows for stringent tests of the leading twist dominance of DVCS and TCS amplitudes. Moreover, this study helps to understand quantitatively the complementarity of DVCS and TCS measurements to test the universality of generalized parton distributions, which is crucial e.g. to perform the nucleon tomography.
Comments:
9 pages, 9 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1912.09853 [pdf]
EPJC(2020)·29 citations
12
[Submitted on 20 Dec 2019] (cross-list from hep-ph)
New CTEQ global analysis of quantum chromodynamics with high-precision data from the LHC
Tie-Jiun Hou🇨🇳 · Jun Gao🇨🇳 · T. J. Hobbs🇺🇸 · Keping Xie🇺🇸 · Sayipjamal Dulat🇨🇳 · Marco Guzzi🇺🇸 · Joey Huston🇺🇸 · Pavel Nadolsky🇺🇸 · Jon Pumplin🇺🇸 · Carl Schmidt🇺🇸 · Ibrahim Sitiwaldi🇨🇳 · Daniel Stump🇺🇸 · C.-P. Yuan🇺🇸
We present the new parton distribution functions (PDFs) from the CTEQ-TEA collaboration, obtained using a wide variety of high-precision Large Hadron Collider (LHC) data, in addition to the combined HERA I+II deep-inelastic scattering data set, along with the data sets present in the CT14 global QCD analysis. New LHC measurements in single-inclusive jet production with the full rapidity coverage, as well as production of Drell-Yan pairs, top-quark pairs, and high- $p_{T}$ $Z$ bosons, are included to achieve the greatest sensitivity to the PDFs. The parton distributions are determined at NLO and NNLO, with each of these PDFs accompanied by error sets determined using the Hessian method. Fast PDF survey techniques, based on the Hessian representation and the Lagrange Multiplier method, are used to quantify the preference of each data set to quantities such as $α_{s} (m_{Z})$ , and the gluon and strange quark distributions. We designate the main resulting PDF set as CT18. The ATLAS 7 TeV precision $W / Z$ data are not included in CT18, due to their tension with other data sets in the global fit. Alternate PDF sets are generated including the ATLAS precision 7 TeV $W / Z$ data (CT18A), a new scale choice for low- $x$ DIS data (CT18X), or all of the above with a slightly higher choice for the charm mass (CT18Z). Theoretical calculations of standard candle cross sections at the LHC (such as the $g g$ fusion Higgs boson cross section) are presented.
Comments:
106 pages + 10 pages supplemental material, 88 figures and 13 tables; discussions expanded with additional results and references
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
1912.10053 [pdf]
PRD(2021)·1013 citations
13
[Submitted on 20 Dec 2019] (cross-list from hep-ph)
Hadron multiplicity calculation: a configurational entropy approach to the saturation scale in QCD
Gayane Karapetyan🇧🇷
This paper investigates the configurational entropic content of hadron-nucleus collisions. Hadron multiplicities and Au nuclei are employed to compute the critical points of the configurational entropy as a function of the saturation scale in deep inelastic scatterings, in QCD. The results match phenomenological data to the precision of 0.39%.
Comments:
4 pages , 1 figure
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1912.10071 [pdf]
EPL(2020)·22 citations
14
[Submitted on 21 Dec 2019] (cross-list from cond-mat.quant-gas)
The Gor'kov and Melik-Barkhudarov correction to the mean-field critical field transition to Fulde-Ferrell-Larkin-Ovchinnikov states
Heron Caldas · Qijin Chen
The Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states, characterized by Cooper pairs condensed at finite-momentum are, at the same time, exotic and elusive. It is partially due to the fact that the FFLO states allow superconductivity to survive even in strong magnetic fields at the mean-field level. The effects of induced interactions at zero temperature are calculated in both clean and dirty cases, and it is found that the critical field at which the quantum phase transition to an FFLO state occurs at the mean-field level is strongly suppressed in imbalanced Fermi gases. This strongly shrinks the phase space region where the FFLO state is unstable and more exotic ground state is to be found. In the presence of high level impurities, this shrinkage may destroy the FFLO state completely.
Comments:
13 pages, 4 figures, with substantial revisions
Subjects:
Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el); Superconductivity (cond-mat.supr-con); Nuclear Theory (nucl-th)
arXiv:
1912.10215 [pdf]
Annalen Phys.(2020)·0 citations
15
[Submitted on 21 Dec 2019] (cross-list from hep-ph)
Diffractive deeply virtual Compton scattering
Bernard Pire🇫🇷 · Lech Szymanowski🇵🇱 · Samuel Wallon🇫🇷
Diffractive deeply virtual Compton scattering (DiDVCS) is the process $γ^{*} (- Q^{2}) + N \to ρ^{0} + γ^{*} (Q^{'2}) + N^{'}$ , where N is a nucleon or light nucleus, in the kinematical regime of large rapidity gap between the $ρ^{0}$ and the final photon-nucleus system, and in the generalized Bjorken regime where both photon virtualities $Q^{2}$ and $Q^{'2}$ are large. We show that this process has the unique virtue of combining the large diffractive cross sections at high energy with the tomographic ability of deeply virtual Compton scattering to scrutinize the quark and gluon content of nucleons and light nuclei. Its study at an electron-ion collider would enlighten the internal structure of hadrons.
Comments:
5 pages, 3 figures. published in Phys. Rev. D 101 , 074005 (2020). v2 includes changes described in the erratum published in PHYSICAL REVIEW D 103, 059901(E) (2021)
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1912.10353 [pdf]
PRD(2020)·21 citations
16
[Submitted on 23 Dec 2019] (cross-list from physics.atom-ph)
Time- and parity-violating effects of nuclear Schiff moment in molecules and solids
V. V. Flambaum🇦🇺 · V. A. Dzuba🇦🇺 · H. B. Tran Tan🇦🇺
We show that existing calculations of the interaction between nuclear Schiff moments and electrons in molecules use an inaccurate operator which gives rise to significant errors. By comparing the matrix elements of the accurate and imprecise Schiff moment operators, we calculated the correction factor as a function of the nuclear charge Z and presented corrected results for the T,P-violating interaction of the nuclear spin with the molecular axis in the TlF, RaO, PbO, TlCN, ThO, AcF molecules and in the ferroelectric solid PbTiO $_{3}$ .
Comments:
4 pages, 1 figure
Subjects:
Atomic Physics (physics.atom-ph); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th); physics.chem-ph (physics.chem-ph)
arXiv:
1912.10620 [pdf]
PRA(2020)·12 citations
17
[Submitted on 23 Dec 2019] (cross-list from hep-ph)
Radiative processes and jet modification at the EIC
Ivan Vitev🇺🇸
A U.S.-based Electron-Ion Collider will provide the ultimate capability to determine both the structure and properties of nucleons and nuclei, as well as how matter and energy can be transported through a strongly interacting quantum mechanical environment. The production and propagation of long-lived heavy subatomic particles is a unique and critical part of this planned decade-long research program. In these proceedings we report the derivation of all branching processes in nuclei that lead to a modification of semi-inclusive hadron production, jet cross sections, and jet substructure when compared to the vacuum. This work allows for their evaluation to any desired order in opacity. As an example, we show an application to the modification of light hadron and open heavy flavor fragmentation functions at the EIC. We discuss how this observable can shed light on the physics of hadronization and parton energy loss in large nuclei.
Comments:
Proceedings of the of the INT program "Probing Nucleons and Nuclei in High Energy Collisions (INT 18-3)" 4 pages, 2 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
1912.10965 [pdf]
4 citations
18
[Submitted on 23 Dec 2019] (cross-list from hep-lat)
Dense 2-color QCD towards continuum and chiral limits
Tamer Boz🇮🇪 · Pietro Giudice🇮🇹 · Simon Hands🇬🇧 · Jon-Ivar Skullerud🇮🇪
We study two-color QCD with two flavors of Wilson fermion as a function of quark chemical potential mu and temperature T, for two different lattice spacings and two different quark masses. We find that the quarkyonic region, where the behaviour of the quark number density and the diquark condensate are described by a Fermi sphere of almost free quarks distorted by a BCS gap, extends to larger chemical potentials with decreasing lattice spacing or quark mass. In both cases, the quark number density also approaches its non-interacting value. The pressure at low temperature is found to approach the Stefan-Boltzmann limit from below.
Comments:
11 pages, 18 figures. Extended discussion of Polyakov loop and deconfinement temperature and of finite volume effects. Various minor modifications and clarifications. Matches version published in PRD
Subjects:
High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
1912.10975 [pdf]
PRD(2020)·60 citations
19
[Submitted on 23 Dec 2019] (cross-list from astro-ph.HE)
Constraining the dense matter equation of state with joint analysis of NICER and LIGO/Virgo measurements
G. Raaijmakers🇳🇱 · S. K. Greif🇩🇪 · T. E. Riley🇳🇱 · T. Hinderer🇳🇱 · K. Hebeler🇩🇪 · A. Schwenk🇩🇪 · A. L. Watts🇳🇱 · S. Nissanke🇳🇱 · S. Guillot🇫🇷 · J. M. Lattimer🇺🇸 · R. M. Ludlam🇺🇸
The NICER collaboration recently published a joint estimate of the mass and the radius of PSR J0030+0451, derived via X-ray pulse-profile modeling. Raaijmakers et al. (2019) explored the implications of this measurement for the dense matter equation of state (EOS) using two parameterizations of the high-density EOS: a piecewise-polytropic model, and a model based on the speed of sound in neutron stars. In this work we obtain further constraints on the EOS following this approach, but we also include information about the tidal deformability of neutron stars from the gravitational wave signal of the compact binary merger GW170817. We compare the constraints on the EOS to those set by the recent measurement of a 2.14 solar mass pulsar, included as a likelihood function approximated by a Gaussian, and find a small increase in information gain. To show the flexibility of our method, we also explore the possibility that GW170817 was a neutron star-black hole merger, which yields weaker constraints on the EOS.
Comments:
18 pages, 8 figures. Accepted for publication in ApJ Letters
Subjects:
High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
arXiv:
1912.11031 [pdf]
ApJL(2020)·279 citations
20
[Submitted on 23 Dec 2019] (cross-list from hep-th)
Vortical effects in Dirac fluids with vector, chiral and helical charges
Victor E. Ambrus🇷🇴 · M. N. Chernodub🇫🇷
Helicity of free massless Dirac fermions is a conserved, Lorentz-invariant quantity at the level of the classical equations of motion. For a generic ensemble consisting of particles and antiparticles, the helical and chiral charges are different conserved quantities. The flow of helicity can be modelled by the helicity current, which is again conserved in the absence of interactions. Similar to the axial vortical effect which generates an axial (chiral) current, the helicity current is induced by vorticity in a finite temperature medium with vector (electrical) charge imbalance via the helical vortical effects, leading to new nondissipative transport phenomena. These phenomena lead to the appearance of a new hydrodynamic excitation, the helical vortical wave. Our results suggest the existence of a new type of triangle anomalies in QED which involve the helicity currents in addition to the standard vector and axial currents. Further exploiting the conservation of the helical current, we show that a finite helical chemical potential may be used to characterise thermodynamic ensembles of fermions similarly to, but independently of, the vector charge and chirality. We derive the pressure $P$ for fermions at finite vector, axial and helical chemical potentials and show that the quantities arising in anomalous transport, including various vortical and circular conductivities and the shear-stress coefficients, can be obtained by differentiation of $P$ with respect to the appropriate chemical potentials. Finally, we calculate the helicity relaxation time in the quark-gluon plasma above the crossover and show that it is similar to that for the axial charge.
Comments:
29 pages, one figure, three tables
Subjects:
High Energy Physics — Theory (hep-th); Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Nuclear Theory (nucl-th)
arXiv:
1912.11034 [pdf]
EPJC(2023)·40 citations

Affiliations

first authorsco-authorsvia INSPIRE