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Nuclear Theory·nucl-th

Thursday·January 21, 2021

7 papers—5 primary·2 cross-listed

All7Primary5Cross-lists2
  1. 06

    [Submitted on 19 Jan 2021] (cross-list from hep-ph)

    Combined Constraints on First Generation Leptoquarks

    Andreas Crivellin · Dario Müller · Luc Schnell

    In this article we perform a combined analysis of low energy precision constraints and LHC searches for leptoquarks which couple to first generation fermions. Considering all ten leptoquark representations, five scalar and five vector ones, we study at the precision frontier the constraints from , , and mixing, as well as from experiments searching for parity violation (APV and QWEAK). We include LHC searches for -channel single resonant production, pair production and Drell-Yan-like signatures of leptoquarks. Interestingly, we find that the recent non-resonant di-lepton analysis of ATLAS provides stronger bounds than the resonant searches recasted so far to constrain -channel production of leptoquarks. Taking into account all these bounds, we observe that none of the leptoquark representations can address the so-called "Cabibbo angle anomaly" via a direct contribution to super-allowed beta decays.

    Comments:
    12 pages, 3 figures, 2 tables, missing factor 2 in non-resonant ATLAS bounds corrected
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2101.07811 [pdf]
    Phys. Rev. D 103, 115023 (2021)
  2. 07

    [Submitted on 20 Jan 2021] (cross-list from hep-ph)

    Renormalization group improved pressure for hot and dense quark matter

    Jean-Loïc Kneur🇫🇷 · Marcus Benghi Pinto🇧🇷 · Tulio E. Restrepo🇧🇷

    We apply the renormalization group optimized perturbation theory (RGOPT) to evaluate the quark contribution to the QCD pressure at finite temperatures and baryonic densities, at next-to-leading order (NLO). Our results are compared to NLO and state-of-the-art higher orders of standard perturbative QCD (pQCD) and hard thermal loop perturbation theory (HTLpt). The RGOPT resummation provides a nonperturbative approximation, exhibiting a drastically better remnant renormalization scale dependence than pQCD, thanks to built-in renormalization group invariance consistency. At NLO, upon simply adding to the RGOPT-resummed quark contributions the purely perturbative NLO glue contribution, our results show a remarkable agreement with ab initio lattice simulation data for temperatures , with a remnant scale dependence drastically reduced as compared to HTLpt.

    Comments:
    24 pages, 17 figures. v2: some clarifications + 2 figures + references added. To appear in Phys. Rev. D
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Lattice (hep-lat); Nuclear Theory (nucl-th)
    arXiv:
    2101.08240 [pdf]
    PRD(2021)·11 citations

Affiliations

first authorsco-authorsvia INSPIRE