Nuclear Theory·nucl-th
9 papers—4 primary·5 cross-listed
[Submitted on 4 Nov 2021] (cross-list from hep-ph)
Colin M. Weller🇺🇸 · Gerald A. Miller🇺🇸
Three current models of QCD in (1+1) dimensions are examined and extended in light-front coordinates. A pion of high momentum is found to have an infinite extent along its direction of motion.
[Submitted on 5 Nov 2021] (cross-list from hep-ph)
Georgy Donchenko🇷🇺 · Konstantin Kouzakov🇷🇺 · Alexander Studenikin🇷🇺
Neutrino scattering on liquid and solid targets at low energy transfer can serve both as a tool for searching the physics beyond the Standard Model, for example, such as neutrino electromagnetic interactions, and as a test of the Standard Model at low-energy scale. At the same time, the theoretical apparatus for low-energy elastic neutrino scattering on electrons and nuclei bound in liquids and solids must take into account collective effects in the electron and nuclear subsystems of the target. We develop such an apparatus based on the formalism of the dynamic structure factor. A numerical illustration of the role of the collective effects is provided for the case of a superfluid He-4 target.
[Submitted on 5 Nov 2021] (cross-list from hep-ph)
Nicolas Kovensky🇫🇷 · Aaron Poole🇬🇧 · Andreas Schmitt🇬🇧
We employ the recently improved description of dense baryonic matter within the Witten-Sakai-Sugimoto model to construct neutron stars. In contrast to previous holographic approaches, the presence of an isospin asymmetry allows us to implement beta equilibrium and electric charge neutrality. As a consequence, we are able to model the crust of the star within the same formalism and compute the location of the crust-core transition dynamically. After showing that a simple pointlike approximation for the baryons fails to satisfy astrophysical constraints, we demonstrate that our improved description does account for neutron stars that meet the current experimental constraints for mass, radius, and tidal deformability. However, we also point out tensions in the parameter fit and large- artifacts and discuss how to potentially resolve them in the future.
[Submitted on 5 Nov 2021] (cross-list from hep-ph)
Andreas Ipp🇦🇹 · David I. Müller🇦🇹 · Daniel Schuh🇦🇹
The study of jets in heavy-ion collisions provides important information about the interaction of partons with the medium that they traverse. The seeds of jets are highly energetic partons, which are produced from hard scatterings during the collision event. As such, they are affected by all different stages of the medium's time evolution, including the glasma, which is the pre-equilibrium precursor state of the quark-gluon plasma. Here we report on our numerical lattice simulations of partons traversing the boost-invariant, non-perturbative glasma as created at the early stages of collisions at RHIC and LHC. We find that partons quickly accumulate transverse momentum up to the saturation momentum during the glasma stage. Furthermore, we observe an interesting anisotropy in transverse momentum broadening of partons with larger broadening in the rapidity than in the azimuthal direction. Its origin can be related to correlations among the longitudinal color-electric and color-magnetic flux tubes in the initial state of the glasma. We compare these observations to the semi-analytic results obtained by a weak-field approximation, where we also find such an anisotropy in a parton's transverse momentum broadening.
[Submitted on 5 Nov 2021] (cross-list from hep-lat)
Adrien Florio🇺🇸 · Eduardo Grossi🇺🇸 · Alexander Soloviev🇺🇸 · Derek Teaney🇺🇸
We perform a real-time simulation of the critical point of QCD, which lies in the dynamic universality class of Model G. The axial charge and the order parameter exhibit a rich dynamical interplay, which reflects the qualitative differences in the hydrodynamic effective theories above and below . From the axial charge correlators on the critical line we extract a dynamical critical exponent of , which is compatible with the theoretical expectation of (with ) when systematic errors are taken into account. At low temperatures, we quantitatively match the simulations to the superfluid effective theory of soft pions.
first authorsco-authorsvia INSPIRE