PaperPanorama
FAQ

Nuclear Theory·nucl-th

Monday·August 27, 2018

8 papers—4 primary·4 cross-listed

All8Primary4Cross-lists4
  1. 05

    [Submitted on 23 Aug 2018] (cross-list from hep-ph)

    angularity distributions at NNLL accuracy

    Guido Bell🇩🇪 · Andrew Hornig🇺🇸 · Christopher Lee🇺🇸 · Jim Talbert🇩🇪

    We present predictions for the event shape angularities at NNLL resummed and matched accuracy and compare them to LEP data at center-of-mass energies GeV and GeV. We perform the resummation within the framework of Soft-Collinear Effective Theory, and make use of recent results for the two-loop angularity soft function. We determine the remaining NNLL and ingredients from a fit to the EVENT2 generator, and implement a shape function with a renormalon-free gap parameter to model non-perturbative effects. Using values of the strong coupling and the universal non-perturbative shift parameter that are consistent with those obtained in previous fits to the thrust and -parameter distributions, we find excellent agreement between our predictions and the LEP data for all angularities with . This provides a robust test of the predictions of QCD, factorization, and the universal scaling of the non-perturbative shift across different angularities. Promisingly, our results indicate that current degeneracies in the parameter space could be be alleviated upon fitting these parameters to experimental data for the angularity distributions.

    Comments:
    51 pages + appendices, 18 figures. v2: minor clarifications and corrections, references updated. v3: version published in JHEP
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    1808.07867 [pdf]
    JHEP(2019)·69 citations
  2. 06

    [Submitted on 23 Aug 2018] (cross-list from quant-ph)

    Dynamical topological transitions in the massive Schwinger model with a {\theta}-term

    T. V. Zache🇩🇪 · N. Mueller🇺🇸 · J. T. Schneider🇩🇪 · F. Jendrzejewski🇩🇪 · J. Berges🇩🇪 · P. Hauke🇩🇪

    Aiming at a better understanding of anomalous and topological effects in gauge theories out-of-equilibrium, we study the real-time dynamics of a prototype model for CP-violation, the massive Schwinger model with a -term. We identify dynamical quantum phase transitions between different topological sectors that appear after sufficiently strong quenches of the -parameter. Moreover, we establish a general dynamical topological order parameter, which can be accessed through fermion two-point correlators and, importantly, which can be applied for interacting theories. Enabled by this result, we show that the topological transitions persist beyond the weak-coupling regime. Finally, these effects can be observed with table-top experiments based on existing cold-atom, superconducting-qubit, and trapped-ion technology. Our work, thus, presents a significant step towards quantum simulating topological and anomalous real-time phenomena relevant to nuclear and high-energy physics.

    Comments:
    6 pages, 3 figures
    Subjects:
    Quantum Physics (quant-ph); Quantum Gases (cond-mat.quant-gas); Strongly Correlated Electrons (cond-mat.str-el); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1808.07885 [pdf]
    PRL(2019)·121 citations
  3. 07

    [Submitted on 23 Aug 2018] (cross-list from hep-ph)

    Stationary and non-stationary solutions of the evolution equation for neutrino in matter

    A. V. Chukhnova🇷🇺 · A. E. Lobanov🇷🇺

    We study solutions of the equation which describes the evolution of a neutrino propagating in dense homogeneous medium in the framework of the quantum field theory. In the two-flavor model the explicit form of Green function is obtained, and as a consequence the dispersion law for a neutrino in matter is derived. It is shown that there exist both the solutions describing the stationary states and the solutions describing the spin-flavor coherent states of the neutrino. The stationary states may be different from the mass eigenstates, and the wave function of a state with a definite flavor should be constructed as a linear combination of the wave functions of the stationary states with coefficients, which depend on the mixing angle in matter. In the ultra-relativistic limit the wave functions of the spin-flavor coherent states coincide with the solutions of the quasi-classical evolution equation. Quasi-classical approximation of the wave functions of spin-flavor coherent states is used to calculate the probabilities of transitions between neutrino states with definite flavor and helicity.

    Comments:
    11 pages, 6 figures, revised version
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    1808.07926 [pdf]
    EPJ Web Conf.(2018)·1 citation
  4. 08

    [Submitted on 24 Aug 2018] (cross-list from cond-mat.stat-mech)

    Density Renormalization Group for Classical Liquids

    Satoshi Iso🇯🇵 · Kiyoharu Kawana🇯🇵

    We study response of liquid to a scale transformation, which generates a change of the liquid density, and obtain a set of differential equations for correlation functions. The set of equations, which we call density renormalization group equations (DRGEs), is similar to the BBGKY hierarchy as it relates different multiple-point correlation functions. In particular, we derive DRGEs for one-particle irreducible vertex functions of liquid by performing Legendre transformations, which enables us to calculate properties of liquid at higher density in terms of correlation functions at lower density.

    Comments:
    39 pages; version to appear in PTEP
    Subjects:
    Statistical Mechanics (cond-mat.stat-mech); High Energy Physics — Theory (hep-th); Nuclear Theory (nucl-th)
    arXiv:
    1808.08133 [pdf]
    PTEP(2019)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE