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Nuclear Theory·nucl-th

Friday·March 30, 2018

7 papers—2 primary·5 cross-listed

All7Primary2Cross-lists5
  1. 03

    Complementary Polynomials From Rodrigues' Representations For Confluent And Hypergeometric Functions And More

    H. J. Weber

    Complementary polynomials of Legendre polynomials are briefly presented, as well as those for the confluent and hypergeometric functions, relativistic Hermite polynomials and corresponding new pre-Laguerre polynomials. The generating functions are all given in closed form and are much simpler than the standard ones. Some are simply polynomials in two variables. New recursions and addition formulas are derived.

    ↳ math.APhep-phmath.CAnucl-th0 citations
  2. 04

    Ghostbusters: Unitarity and Causality of Non-equilibrium Effective Field Theories

    Ping Gao🇺🇸 · Paolo Glorioso🇺🇸 · Hong Liu🇺🇸

    For a non-equilibrium physical system defined along a closed time path (CTP), a key constraint is the so-called largest time equation, which is a consequence of unitarity and implies causality. In this paper, we present a simple proof that if the propagators of a non-equilibrium effective action have the proper pole structure, the largest time equation is obeyed to all loop orders. Ghost fields and BRST symmetry are not needed. In particular, the arguments for the proof can also be used to show that if ghost fields are introduced, their contributions vanish.

    ↳ hep-thcond-mat.stat-mechnucl-thJHEP(2020)·51 citations
  3. 05

    Nuclear parton density functions from dijet photoproduction at the EIC

    M. Klasen🇩🇪 · K. Kovarik🇩🇪

    We study the potential of dijet photoproduction measurements at a future electron-ion collider (EIC) to better constrain our present knowledge of the nuclear parton distribution functions. Based on theoretical calculations at next-to-leading order and approximate next-to-next-to-leading order of perturbative QCD, we establish the kinematic reaches for three different EIC designs, the size of the parton density function modifications for four different light and heavy nuclei from He-4 over C-12 and Fe-56 to Pb-208 with respect to the free proton, and the improvement of EIC measurements with respect to current determinations from deep-inelastic scattering and Drell-Yan data alone and when also considering data from existing hadron colliders.

    ↳ hep-phhep-exnucl-exnucl-thPRD(2018)·24 citations
  4. 06

    Systematic analysis of double-scale evolution

    Ignazio Scimemi🇪🇸 · Alexey Vladimirov🇩🇪

    Often the factorization of differential cross sections results in the definition of fundamental hadronic functions/distributions which have a double-scale evolution, as provided by a pair of coupled equations. Typically, the two scales are the renormalization and rapidity scales. The two-dimensional structure of their evolution is the object of the present study . In order to be more specific, we consider the case of the transverse momentum dependent distributions (TMD). Nonetheless, most of our findings can be used with other double-scale parton distributions. On the basis of the two-dimensional structure of TMD evolution, we formulate the general statement of the -prescription introduced in \cite{Scimemi:2017etj}, and we define an optimal TMD distribution, which is a scaleless model-independent universal non-perturbative function. A significant part of this work is devoted to the study of the effects of truncation of perturbation theory on the double-scale evolution. We show that within truncated perturbation theory the solution of evolution equations is ambiguous and this fact generates extra uncertainties within the resummed cross-section. The alternatives to bypass this issue are discussed. We discuss the effects of the scale variation effects and show that these uncertainties reduce within the non-ambiguous solutions that we propose.

    ↳ hep-phhep-exhep-latnucl-thJHEP(2018)·98 citations
  5. 07

    Event engineering studies for heavy flavor production and hadronization in high multiplicity hadron-hadron and hadron-nucleus collisions

    Yan-Qing Ma🇨🇳 · Prithwish Tribedy🇺🇸 · Raju Venugopalan🇺🇸 · Kazuhiro Watanabe🇺🇸

    Heavy flavor measurements in high multiplicity proton-proton and proton-nucleus collisions at collider energies enable unique insights into their production and hadronization mechanism because experimental and theoretical uncertainties cancel in ratios of their cross-sections relative to minimum bias events. We explore such event engineering using the Color Glass Condensate (CGC) effective field theory to compute short distance charmonium cross-sections. The CGC is combined with heavy-quark fragmentation functions to compute -meson cross-sections; for the , hadronization is described employing Nonrelativistic QCD (NRQCD) and an Improved Color Evaporation model. Excellent agreement is found between the CGC computations and the LHC heavy flavor data in high multiplicity events. Event engineering in this CGC+NRQCD framework reveals a very rapid growth in the fragmentation of the state in rare events relative to minimum bias events.

    ↳ hep-phhep-exnucl-exnucl-thPRD(2018)·73 citations

Affiliations

first authorsco-authorsvia INSPIRE