Nuclear Theory·nucl-th

Friday·April 1, 2022

11 papers—5 primary·6 cross-listed

06
[Submitted on 30 Mar 2022] (cross-list from hep-ph)
Exponential Approach to the Hydrodynamic Attractor in Yang-Mills Kinetic Theory
Xiaojian Du🇩🇪 · Michal P. Heller🇧🇪 · Sören Schlichting🇩🇪 · Viktor Svensson🇸🇪
We use principal component analysis to study the hydrodynamic attractor in Yang-Mills kinetic theory undergoing the Bjorken expansion with Color Glass Condensate initial conditions. The late time hydrodynamic attractor is characterized by a single principal component determining the overall energy scale. How it is reached is governed by the disappearance of single subleading principal component characterizing deviations of the pressure anisotropy, the screening mass and the scattering rate. We find that for wide range of couplings the approach to the hydrodynamic attractor at late times is well described by an exponential. Its decay rate dependence on the coupling turns out to translate into a simple dependence on the shear viscosity to entropy density ratio.
Comments:
12 pages, 7 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
arXiv:
2203.16549 [pdf]
PRD(2022)·34 citations
07
[Submitted on 30 Mar 2022] (cross-list from hep-ph)
Speed of Sound for Hadronic and Quark Phases in a Magnetic Field
E. J. Ferrer🇺🇸 · A. Hackebill🇺🇸
In this paper we calculate the speed of sound for three phases that may exist inside a magnetized hybrid neutron star at different density regions: A hadronic phase at low densities, quark-matter in the magnetic dual chiral density wave (MDCDW) phase at intermediate densities and a free-quark phase modeled by the MIT bag model at higher densities. It is found that the speed of sound exhibits a non-monotonic behavior, that goes from values smaller than the conformal limit ( $c_{s}^{2} < 1/3$ ) in the hadronic phase, to peak ( $c_{s}^{2} > 1/3$ ) in the MDCDW phase, to finally reach the conformal limit ( $c_{s}^{2} \sim 1/3$ ) at higher densities for quarks in the MIT bag model. Also, the anisotropic speed of sound in the presence of a magnetic field is derived from first principles. This is a consequence of the anisotropy in the system's pressures produced by the breaking of the rotational symmetry in the presence of a magnetic field. The role played by the lowest Landau level contribution in affecting the speed of sound in the magnetized phases is discussed.
Comments:
Version to appear in Nucl. Phys. A
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2203.16576 [pdf]
NPA(2023)·22 citations
08
[Submitted on 31 Mar 2022] (cross-list from hep-ph)
Exclusive production of light vector mesons at next-to-leading order in the dipole picture
Heikki Mäntysaari🇫🇮 · Jani Penttala🇫🇮
Exclusive production of light vector mesons in deep inelastic scattering is calculated at next-to-leading order in the dipole picture in the limit of high photon virtuality. The resulting expression is free of any divergences and suitable for numerical evaluations. The higher-order corrections are found to be numerically important, but they can be mostly captured by the nonperturbative fit parameters describing the initial condition for the small- $x$ evolution of the dipole scattering amplitude. The vector meson production cross section is shown to depend only weakly on the meson distribution amplitude and the factorization scale. We also present phenomenological comparisons of our result to the existing exclusive $ϕ$ and $ρ$ production data from HERA and find an excellent agreement at high virtualities.
Comments:
25 pages, 25 figures; v2: Corrected typos, modified discussion at the end of Sec. IV
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2203.16911 [pdf]
PRD(2022)·47 citations
09
[Submitted on 31 Mar 2022] (cross-list from hep-ph)
Accessing pion GPDs through the Sullivan process: is it feasible?
Jose Manuel Morgado Chávez🇪🇸 · Valerio Bertone🇫🇷 · Maxime Defurne🇫🇷 · Feliciano de Soto🇪🇸 · Cédric Mezrag🇫🇷 · Hervé Moutarde🇫🇷 · José Rodríguez-Quintero🇪🇸 · Jorge Segovia🇪🇸
Describing hadronic structure is one of the most intriguing problems in physics. In this respect, generalized parton distributions (GPDs) constitute an outstanding tool, allowing to draw "three dimensional pictures" of hadron's inside. Starting from contemporary models for pion's GPDs fulfilling all constraints imposed by QCD, we compute Compton form factors (CFFs) of pions subjected to deeply virtual Compton scattering. We show the behaviour of CFFs to be gluon-dominated at EIC's kinematics. Finally we evaluate lepton-beam-spin asymmetries in the Sullivan process, demonstrating the existence of such and thus triggering optimism about the possibility of probing pion's 3D structure at electron-ion colliders.
Comments:
Proceedings of the 19th International Conference on Hadron Spectroscopy and Structure in memoriam Simon Eidelman (HADRON2021), 26-31 July (2021), Mexico City (Mexico). To appear in Suplemento de la Revista Mexicana de Física
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2203.16947 [pdf]
Rev.Mex.Fis.Suppl.(2022)·4 citations
10
[Submitted on 31 Mar 2022] (cross-list from hep-ph)
Analytic Map of Three-Channel S Matrix -Generalized Uniformization and Mittag-Leffler Expansion-
Wren A. Yamada🇯🇵 · Osamu Morimatsu🇯🇵 · Toru Sato🇯🇵
We explore the analytic structure of the three-channel $S$ matrix by generalizing uniformization and making a single-valued map for the three-channel $S$ matrix. First, by means of the inverse Jacobi's elliptic function we construct a transformation from eight Riemann sheets of the center-of-mass energy squared complex plane onto a torus, on which the three-channel $S$ matrix is represented single-valued. Secondly, we show that the Mittag-Leffler expansion, a pole expansion, of the three-channel scattering amplitude includes not only topologically trivial but also nontrivial contributions and is given by the Weierstrass zeta function. Finally, we examine the obtained formula in the context of a simple three-channel model. Taking a simple non-relativistic effective field theory with contact interaction for the $S = - 2$ , $I = 0$ , $J^{P} = 0^{+}$ , $ΛΛ - N Ξ - ΣΣ$ coupled-channel scattering, we demonstrate that the scattering amplitude as a function of the uniformization variable is, in fact, given by the Mittag-Leffler expansion with the Weierstrass zeta function and that it is dominated by contributions from neighboring poles.
Comments:
7 pages, 7 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2203.17069 [pdf]
PRL(2022)·9 citations
11
[Submitted on 31 Mar 2022] (cross-list from hep-ph)
Triangle singularities in the $T_{cc}^{+} \to D^{*+} D^{0} \to π^{+} D^{0} D^{0}$ decay width
N.N. Achasov🇷🇺 · G.N. Shestakov🇷🇺
The values of the masses of the particles involved in the decay of $T_{cc}^{+} \to D^{*+} D^{0} \to π^{+} D^{0} D^{0}$ suggest that due to the final state interactions in the transition vertex $T_{cc}^{+} \to D^{*+} D^{0}$ there may be triangle logarithmic singularities. We discuss their possible role and show that the tree approximation for calculating the decay widths $T_{cc}^{+} \to (D^{*+} D^{0} + D^{* 0} D^{+}) \to π^{+} D^{0} D^{0}$ , $π^{0} D^{0} D^{+}$ , $γ D^{0} D^{+}$ is quite sufficient at the current level of measurement accuracy.
Comments:
5 pages, 4 figures; v2: published version, elusidations and four references added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2203.17100 [pdf]
PRD(2022)·20 citations

Affiliations

first authorsco-authorsvia INSPIRE

Exponential Approach to the Hydrodynamic Attractor in Yang-Mills Kinetic Theory

Speed of Sound for Hadronic and Quark Phases in a Magnetic Field

Exclusive production of light vector mesons at next-to-leading order in the dipole picture

Accessing pion GPDs through the Sullivan process: is it feasible?

Analytic Map of Three-Channel S Matrix -Generalized Uniformization and Mittag-Leffler Expansion-

Triangle singularities in the Tcc+​→D∗+D0→π+D0D0 decay width

Affiliations

Triangle singularities in the $T_{cc}^{+} \to D^{*+} D^{0} \to π^{+} D^{0} D^{0}$ decay width