Nuclear Theory·nucl-th
7 papers—3 primary·4 cross-listed
[Submitted on 31 Aug 2022] (cross-list from hep-ph)
Written version of the theoretical summary lecture presented at the Strangeness in Quark Matter 2022 conference.
[Submitted on 31 Aug 2022] (cross-list from hep-lat)
Andrei Alexandru🇺🇸 · Paulo F. Bedaque🇺🇸 · Andrea Carosso🇺🇸 · Michael J. Cervia🇺🇸 · Andy Sheng🇺🇸
Quantum simulations of bosonic field theories require a truncation in field space to map the theory onto finite quantum registers. Ideally, the truncated theory preserves the symmetries of the original model and has a critical point in the same universality class. In this paper, we explore two different truncations that preserve the symmetries of the 1+1-dimensional non-linear -model - one that truncates the Hilbert space for the unit sphere by setting an angular momentum cutoff and a fuzzy sphere truncation inspired by non-commutative geometry. We compare the spectrum of the truncated theories in a finite box with the full theory. We use open boundary conditions, a novel method that improves on the correlation lengths accessible in our calculations. We provide evidence that the angular-momentum truncation fails to reproduce the -model and that the anti-ferromagnetic fuzzy model agrees with the full theory.
[Submitted on 1 Sept 2022] (cross-list from hep-ph)
Ian Low🇺🇸 · Jing Shu🇨🇳 · Ming-Lei Xiao🇺🇸 · Yu-Hui Zheng🇨🇳
We establish a systematic construction of the on-shell amplitude/operator basis for Chiral Perturbation Theory (ChPT) in spacetime dimensions and with an arbitrary number of flavors . For kinematic factors, we employ spinor-helicity variables to construct the soft blocks, which are local amplitudes satisfying the Adler's zero condition, as well as to take into account the reduction in the kinematic basis due to the Gram determinant, which arises at when the number of multiplicity in an amplitude becomes large: . For flavor factors, we include group-theoretic relations at small , , which decreases the flavor basis. The result is obtained by adapting the Young tensor method of constructing the operator basis for generic effective field theories to the case of non-linearly realized symmetries. Working in the massless quark limit, we present purely mesonic operators for both even- and odd-parity at and for and arbitrary , and establish a direct correspondence between the amplitude basis and the operator basis. Furthermore, the redundancy due to the Gram determinant is studied at for and 10.
[Submitted on 1 Sept 2022] (cross-list from hep-ph)
Yao Li🇨🇳 · Sa Wang🇨🇳 · Ben-Wei Zhang🇨🇳
Heavy-flavor jets are powerful tools to gain insight into the in-medium partonic energy-loss mechanisms and the quark-gluon plasma's (QGP) transport properties in high-energy nuclear collisions. In this work we present the first theoretical study of the longitudinal momentum fraction carried by heavy-flavor mesons in jets in Pb+Pb collisions at = 5.02 TeV. The p+p baseline is provided by POWHEG+PYTHIA8, which matches the next-to-leading-order hard processes with the parton shower. We employ a Monte Carlo transport model, which considers the collisional and radiative partonic energy loss, to simulate the evolution of heavy-flavor jets in the expanding QGP medium. We observe steeper distributions of jets compared to those of jets at the same kinematics region in p+p collisions, which may be a hint of the harder jet fragmentation function of b jets compared to c jets in vacuum. In A+A collisions, it is shown that the jet quenching effect would generally decrease the values of . We have made a systematical study on how several factors, including jet , jet radius , and collision centrality, would influence the medium modification of distributions of a jet. In addition, we predict visibly stronger nuclear modifications of -jet distributions compared to a jet within the same windows as a result of the much steeper initial distribution of the jet in vacuum.
first authorsco-authorsvia INSPIRE