PaperPanorama

Nuclear Theory·nucl-th

Monday·April 27, 2020

10 papers8 primary·2 cross-listed

  1. 09

    Rethinking Jets with Energy Correlators: Tracks, Resummation and Analytic Continuation

    Hao Chen🇨🇳 · Ian Moult🇺🇸 · XiaoYuan Zhang🇨🇳 · Hua Xing Zhu🇨🇳

    We introduce an infinite set of jet substructure observables, derived as projections of -point energy correlators, that are both convenient for experimental studies and maintain remarkable analytic properties derived from their representations in terms of a finite number of light ray operators. We show that these observables can be computed using tracking or charge information with a simple reweighting by integer moments of non-perturbative track or fragmentation functions. Our results for the projected -point correlators are analytic functions of , allowing us to derive resummed results to next-to-leading logarithmic accuracy for all . We analytically continue our results to non-integer values of and define a corresponding analytic continuation of the observable, which we term a -correlator, that can be measured on jets of hadrons at the LHC. This enables observables that probe the leading twist collinear dynamics of jets to be placed into a single analytic family, which we hope will lead to new insights into jet substructure.

    hep-phhep-thnucl-thPRD(2020)·221 citations
  2. 10

    Transverse Momentum Broadening of a Jet in Quark-Gluon Plasma: An Open Quantum System EFT

    Varun Vaidya🇺🇸 · Xiaojun Yao🇺🇸

    We utilize the technology of open quantum systems in conjunction with the recently developed effective field theory for forward scattering to address the question of massless jet propagation through a weakly-coupled quark-gluon plasma in thermal equilibrium. We discuss various possible hierarchies of scales that may appear in this problem, by comparing thermal scales of the plasma with relevant scales in the effective field theory. Starting from the Lindblad equation, we derive and solve a master equation for the transverse momentum distribution of a massless quark jet, at leading orders both in the strong coupling and in the power counting of the effective field theory. Markovian approximation is justified in the weak coupling limit. Using the solution to the master equation, we study the transverse momentum broadening of a jet as a function of the plasma temperature and the time of propagation. We discuss the physical origin of infrared sensitivity that arises in the solution and a way to handle it in the effective field theory formulation. We suspect that the final measurement constraint can only cut-off leading infrared singularities and the solution to the Markovian master equation resums a logarithmic series. This work is a stepping stone towards understanding jet quenching and jet substructure observables on both light and heavy quark jets as probes of the quark-gluon plasma.

    hep-phnucl-thJHEP(2020)·41 citations

Affiliations

first authorsco-authorsvia INSPIRE