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Nuclear Theory·nucl-th

Wednesday·January 10, 2018

4 papers—2 primary·2 cross-listed

All4Primary2Cross-lists2
  1. 03

    [Submitted on 8 Jan 2018] (cross-list from hep-ph)

    Simplicity from Recoil: The Three-Loop Soft Function and Factorization for the Energy-Energy Correlation

    Ian Moult🇺🇸 · Hua Xing Zhu🇨🇳

    We derive an operator based factorization theorem for the energy-energy correlation (EEC) observable in the back-to-back region, allowing the cross section to be written as a convolution of hard, jet and soft functions. We prove the equivalence of the soft functions for the EEC and color singlet transverse-momentum resummation to all-loop order, and give their analytic result to three-loops. Large logarithms appearing in the perturbative expansion of the EEC can be resummed to all orders using renormalization group evolution. We give analytic results for all required anomalous dimensions to three-loop order, providing the first example of a transverse-momentum (recoil) sensitive event shape whose anomalous dimensions are known at this order. The EEC can now be computed to next-to-next-to-next-to-leading logarithm matched to next-to-next-to-leading order, making it a prime candidate for precision QCD studies and extractions of the strong coupling constant. We anticipate that our factorization theorem will also be crucial for understanding non-perturbative power corrections for the EEC, and their relationship to those appearing in other observables.

    Comments:
    32 pages, 3 figures v2. Updated several typos in the text. v3. Final published version. Minor typos updated
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    1801.02627 [pdf]
    JHEP(2018)·150 citations
  2. 04

    [Submitted on 8 Jan 2018] (cross-list from hep-ph)

    Doubly charmed baryon production in heavy ion collisions

    Xiaojun Yao🇺🇸 · Berndt Müller🇺🇸

    We give an estimate of production rate and transverse momentum spectra in relativistic heavy ion collisions. We use Boltzmann transport equations to describe the dynamical evolution of charm quarks and diquarks inside quark-gluon plasma. In-medium formation and dissociation rates of charm diquarks are calculated from potential non-relativistic QCD for the diquark sector. We solve the transport equations by Monte Carlo simulations. For TeV Pb-Pb collisions with centrality, the number of produced in the transverse momentum range GeV and rapidity from to is roughly per collision. We repeat the calculation with a melting temperature MeV above which no diquarks can be formed. The number of produced in the same kinematic region is about per collision. We discuss how to study diquarks at finite temperature on a lattice and construct the anti-triplet free energy in a gauge invariant but path dependent way. We also comment on extensions of the calculation to other doubly heavy baryons and doubly heavy tetraquarks and the feasibility of experimental measurements.

    Comments:
    9 pages, 3 figures, add a discussion of productions of other doubly heavy baryons and doubly heavy tetraquarks; add a discussion on diquark free energy on the lattice; add a comment on experimental feasibility; published version
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1801.02652 [pdf]
    PRD(2018)·57 citations

Affiliations

first authorsco-authorsvia INSPIRE