PaperPanorama
FAQ

Nuclear Theory·nucl-th

Thursday·March 3, 2022

8 papers—3 primary·5 cross-listed

All8Primary3Cross-lists5
  1. 04

    [Submitted on 1 Mar 2022] (cross-list from hep-ph)

    Rapidity evolution of the entanglement entropy in quarkonium: parton and string duality

    Yizhuang Liu🇵🇱 · Maciej A. Nowak🇵🇱 · Ismail Zahed🇺🇸

    We investigate the quantum entanglement in rapidity space of the soft gluon wave function of a quarkonium, in theories with non-trivial rapidity evolutions. We found that the rapidity evolution drastically changes the behavior of the entanglement entropy, at any given order in perturbation theory. At large , the reduced density matrices that "resum" the leading rapidity-logs can be explicitly constructed, and shown to satisfy Balitsky-Kovchegov (BK)-like evolution equations. We study their entanglement entropy in a simplified toy model, and in 3D QCD. The entanglement entropy in these cases, after re-summation, is shown to saturate the Kolmogorov-Sinai bound of 1. Remarkably, in 3D QCD the essential growth rate of the entanglement entropy is found to vanish at large rapidities, a result of kinematical "quenching" in transverse space. The one-body reduction of the entangled density matrix obeys a BFKL evolution equation, which can be recast as an evolution in an emergent AdS space, at large impact-parameter and large rapidity. This observation allows the extension of the perturbative wee parton evolution at low-x, to a dual non-perturbative evolution of string bits in curved AdS space, with manifest entanglement entropy in the confining regime.

    Comments:
    27 pages, 4 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th); Quantum Physics (quant-ph)
    arXiv:
    2203.00739 [pdf]
    PRD(2022)·34 citations
  2. 05

    [Submitted on 1 Mar 2022] (cross-list from hep-ph)

    Proton and pion distribution functions in counterpoint

    Ya Lu🇨🇳 · Lei Chang🇨🇳 · Khépani Raya🇪🇸 · Craig D. Roberts🇨🇳 · José Rodríguez-Quintero🇪🇸

    Working with proton and pion valence distribution functions (DFs) determined consistently at the same, unique hadron scale and exploiting the possibility that there is an effective charge which defines an evolution scheme for DFs that is all-orders exact, we obtain a unified body of predictions for all proton and pion DFs - valence, glue, and four-flavour-separated sea. Whilst the hadron light-front momentum fractions carried by identifiable parton classes are the same for the proton and pion at any scale, the pointwise behaviour of the DFs is strongly hadron-dependent. All calculated distributions comply with quantum chromodynamics constraints on low- and high- scaling behaviour and, owing to emergent hadron mass, pion DFs are the most dilated. These results aid in elucidating the sources of similarities and differences between proton and pion structure.

    Comments:
    8 pages, 4 figures, 2 tables
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2203.00753 [pdf]
    PLB(2022)·58 citations
  3. 06

    [Submitted on 2 Mar 2022] (cross-list from hep-ph)

    Possible studies on generalized parton distributions and gravitational form factors in neutrino reactions

    S. Kumano🇯🇵 · R. Petti🇺🇸

    Spacelike and timelike generalized parton distributions (GPDs) have been investigated in charged-lepton scattering and electron-positron collisions via deeply virtual Compton scattering and two-photon processes, respectively. Furthermore, we expect that hadron-accelerator-facility measurements will be performed in future. The GPDs will play a crucial role in clarifying the origins of hadron spins and masses in terms of quarks and gluons. It is also possible to probe internal pressure within hadrons for understanding their stability. Gravitational form factors of hadrons used to be considered as a purely academic subject because gravitational interactions are too weak to be measured in microscopic systems. However, due to the development of hadron-tomography field, it became possible to extract the gravitational form factors from the actual GPD measurements without relying on direct gravitational interactions. Neutrino reactions can also be used for GPD studies in future, for example, by using the Long-Baseline Neutrino Facility at Fermilab. The neutrino GPD measurements are valuable especially for finding the flavor dependence of the GPDs in a complementary way to the charged-lepton experiments. We give an overview of the GPDs and discuss possible neutrino GPD measurements using the single-pion production processes and .

    Comments:
    7 pages, LaTeX, Proceedings of the 22nd International Workshop on Neutrinos from Accelerators (NuFact2021), September 5-11, 2021, (Online/In person) Cagliari, Italy
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Lattice (hep-lat); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2203.00848 [pdf]
    PoS(2022)·4 citations
  4. 07

    [Submitted on 2 Mar 2022] (cross-list from hep-ph)

    Estimating Elliptic Flow Coefficient in Heavy Ion Collisions using Deep Learning

    Neelkamal Mallick🇮🇳 · Suraj Prasad🇮🇳 · Aditya Nath Mishra🇭🇺 · Raghunath Sahoo🇮🇳 · Gergely Gábor Barnaföldi🇭🇺

    Machine Learning (ML) techniques have been employed for the high energy physics (HEP) community since the early 80s to deal with a broad spectrum of problems. This work explores the prospects of using Deep Learning techniques to estimate elliptic flow () in heavy-ion collisions at the RHIC and LHC energies. A novel method is developed to process the input observables from particle kinematic information. The proposed DNN model is trained with Pb-Pb collisions at TeV minimum bias events simulated with AMPT model. The predictions from the ML technique are compared to both simulation and experiment. The Deep Learning model seems to preserve the centrality and energy dependence of for the LHC and RHIC energies. The DNN model is also quite successful in predicting the dependence of . When subjected to event simulation with additional noise, the proposed DNN model still keeps the robustness and prediction accuracy intact up to a reasonable extent.

    Comments:
    Same as the published version in Phys. Rev. D
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); High Energy Physics — Theory (hep-th); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2203.01246 [pdf]
    PRD(2022)·34 citations
  5. 08

    [Submitted on 2 Mar 2022] (cross-list from hep-th)

    Finite System Size Correction to NLO Scattering in Theory

    W. A. Horowitz🇿🇦 · J. F. Du Plessis🇿🇦

    We compute scattering in massive theory on to NLO. We perform the calculations using "denominator regularization" instead of the usual dimensional regularization, which allows for asymmetric configurations of the . We give a transparent derivation of and equation for the analytic continuation of the generalized Epstein zeta function. We show that the Optical Theorem is satisfied and generalize a conjecture by Hardy on square counting functions. We comment on the implications.

    Comments:
    6 pages. Minor revisions to align the arXiv version with the published Phys.Rev.D Letter version
    Subjects:
    High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2203.01259 [pdf]
    PRD(2022)·17 citations

Affiliations

first authorsco-authorsvia INSPIRE