Nuclear Theory·nucl-th

Friday·July 22, 2022

6 papers—2 primary·4 cross-listed

03
Tackling the infamous $g^{6}$ term of the QCD pressure
Pablo Navarrete🇨🇱 · York Schröder🇨🇱
We report on ongoing efforts to tackle an important open problem in QCD thermodynamics, namely an evaluation of the pressure to order $g^{6}$ in a weak-coupling expansion, corresponding to four loops. In particular, we identify a class of contributing Feynman sum-integrals with lower-loop factors, describe the formalism to tensor decompose those, and manage to map them onto scalar master sum-integrals that have already been evaluated in the literature.
↳ hep-phnucl-thPoS(2022)·7 citations
04
Multiparticle production in proton-nucleus collisions beyond eikonal accuracy
Pedro Agostini🇪🇸 · Tolga Altinoluk🇵🇱 · Néstor Armesto🇪🇸 · Fabio Dominguez🇪🇸 · José Guilherme Milhano🇵🇹
We study the effects on multigluon production at mid-rapidity in the Color Glass Condensate of the non-eikonal corrections that stem from relaxing the shockwave approximation and giving the target a finite size. We extend previous works performed in the dilute-dilute approximation suitable for proton-proton collisions, to the dilute-dense one applicable to proton-nucleus. We employ the McLerran-Venugopalan model for the projectile averages. For the target averages, we use the Golec-Biernat--Wüsthoff model and restrict to the leading contributions in overlap area that allow a factorization of ensembles of Wilson lines into products of dipoles. We make the connection with the jet quenching formalism and compare with previous results in the literature, providing a parametrization of the so-called decorated dipoles. We show that the non-eikonal effects on single inclusive particle production, contrary to what happens in jet quenching, are only sizable, of a few percent, for modest energies $s_{N N} \leq 100$ GeV and central rapidities. On the other hand, we find that the effects on double inclusive gluon production are larger for the same kinematics. We show that, as found previously in the dilute-dilute situation, non-eikonal corrections break the accidental symmetry in the CGC, allowing for the existence of non-vanishing odd azimuthal harmonics.
↳ hep-phnucl-thEPJC(2022)·26 citations
05
First row CKM unitarity
Chien-Yeah Seng🇩🇪
In this talk I briefly review the precision test of the first row CKM unitarity, focusing mainly on $V_{u d}$ and $V_{u s}$ extracted from pion, kaon, neutron and superallowed nuclear beta decays. I will discuss the current status of several important Standard Model theory inputs to these processes, and the need for future improvements.
↳ hep-phhep-exhep-latnucl-ex+13 citations
06
$Λ$ and $Λ ˉ$ global polarization from the core-corona model
Alejandro Ayala🇲🇽 · Isabel Domínguez🇲🇽 · Ivonne Maldonado🇷🇺 · Maria Elena Tejeda-Yeomans🇲🇽
We report on work aimed to describe the $Λ$ and $Λ ˉ$ global polarizations in a heavy-ion collision environment using the core-corona model, where the source of these hyperons is a high-density core and a less dense corona. We show that the overall properties of the polarization excitation functions can be linked to the relative abundance of $Λ$ s and $Λ ˉ$ s coming from the core versus those coming from the corona. Both global polarizations peak at collision energies $s_{N N} ≲ 10$ GeV. The exact positions and heights of these peaks depend not only on a reversal of relative abundances with collision energy, but also on the centrality class, both related to the QGP volume and lifetime.
↳ hep-phnucl-thRev.Mex.Fis.Suppl.(2022)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE

Tackling the infamous g6 term of the QCD pressure

Multiparticle production in proton-nucleus collisions beyond eikonal accuracy

First row CKM unitarity

Λ and Λˉ global polarization from the core-corona model

Affiliations

Tackling the infamous $g^{6}$ term of the QCD pressure

$Λ$ and $Λ ˉ$ global polarization from the core-corona model