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Nuclear Theory·nucl-th

Monday·November 13, 2017

7 papers—5 primary·2 cross-listed

All7Primary5Cross-lists2
  1. 01

    [Submitted on 10 Nov 2017]

    Facets of Neutrino-Nucleus Interactions

    A.B. Balantekin (Wisconsin U., Madison)🇺🇸

    Different approaches to the calculation of neutrino-nucleus cross sections are summarized. Potential impact of improving the nuclear physics input into neutrino interactions and cross section calculations on uncovering new physics is discussed using the example of reactor anomaly. Importance of a thorough understanding of neutrino interactions in astrophysics and cosmology is highlighted.

    Comments:
    Proceedings of the XXXV Mazurian Lakes Conference on Physics, Piaski, Poland, September 3-9, 2017
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1711.03667 [pdf]
    Acta Phys.Polon.B(2018)·2 citations
  2. 02

    [Submitted on 10 Nov 2017]

    Calculation of Power Spectrum in the Little Bangs

    Golam Sarwar🇮🇳 · Sushant K. Singh🇮🇳 · Jan-e Alam🇮🇳

    The power spectrum of fluctuations in the momentum distributions of particles have been estimated with optical Glauber and Monte-Carlo Glauber initial conditions for relativistic heavy ion collisions. The evaluation procedure adopted in this work is analogous to the one used in the calculation of power spectrum in Cosmic Microwave Background Radiation (CMBR). The power spectrum due to perturbations in the phase space distribution of the particles has also been evaluated. The perturbation in phase space has been evolved through the Boltzmann transport equation in an expanding quark gluon plasma (QGP) background. The expansion of the QGP has been treated within the purview of (3+1) dimensional relativistic hydrodynamics. We observe that the non-equlibrium effects introduced as perturbations in the phase space distributions can be traced from the enhancement of the power spectrum as well as through its variation with temperature which is distinctly different from the case of vanishing perturbation. A relation has been derived between the power spectrum and the flow harmonics.

    Comments:
    25 pages, 26 figures
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1711.03743 [pdf]
    Int.J.Mod.Phys.A(2018)·8 citations
  3. 03

    [Submitted on 10 Nov 2017]

    The rank-one separable interaction kernel for nucleon with scalar propagators

    S. G. Bondarenko · V. V. Burov · S. A. Yurev

    In the paper the covariant kernel of the nucleon-nucleon interaction of particles with scalar propagators is analyzed. The Bethe-Salpeter equation for the T matrix is considered in the rank- one separable kernel. The parameters of the kernel for the specific partial-wave channels explicitly connect with the observables { low energy scattering parameters and phase shifts, deuteron binding energy. Covariant separable kernels forthe partial-wave channels with total angular momentum J = 0 (1S0, 3P0) and J = 1 (3S1 -3D1, 1P1, 3P1) are constructed.

    Subjects:
    Nuclear Theory (nucl-th)
    arXiv:
    1711.03781 [pdf]
    Phys.Part.Nucl.Lett.(2018)·3 citations
  4. 04

    [Submitted on 9 Nov 2017]

    Anisotropic-hydrodynamics approach to a quark-gluon fluid mixture

    Wojciech Florkowski🇵🇱 · Ewa Maksymiuk🇵🇱 · Radoslaw Ryblewski🇵🇱

    Anisotropic-hydrodynamics framework is used to describe a mixture of quark and gluon fluids. The effects of quantum statistics, finite quark mass, and finite baryon number density are taken into account. The results of anisotropic hydrodynamics are compared with exact solutions of the coupled kinetic equations for quarks and gluons in the relaxation time approximation. The overall very good agreement between the hydrodynamic and kinetic-theory results is found.

    Comments:
    21 pages, 3 figures. arXiv admin note: text overlap with arXiv:1710.07095
    Subjects:
    Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1711.03872 [pdf]
    PRC(2018)·21 citations
  5. 05

    [Submitted on 10 Nov 2017]

    Robustness of third family solutions for hybrid stars against mixed phase effects

    A. Ayriyan🇷🇺 · N.-U. Bastian🇵🇱 · D. Blaschke🇷🇺 · H. Grigorian🇷🇺 · K. Maslov🇷🇺 · D. N. Voskresensky🇷🇺

    We investigate the robustness of third family solutions for hybrid compact stars with a quark matter core that correspond to the occurrence of high-mass twin stars against a softening of the phase transition by means of a construction that mimics the effects of pasta structures in the mixed phase. We consider a class of hybrid equations of state that exploits a relativistic mean-field model for the hadronic as well as for the quark matter phase. We present parametrizations that correspond to branches of high-mass twin star pairs with maximum masses between and having radius differences between 3.2 km and 1.5 km, respectively. When compared to a Maxwell construction with a fixed value of critical pressure the effect of the mixed phase construction consists in the occurrence of a region of pressures around belonging to the coexistence of hadronic and quark matter phases between the onset pressure at and the end of the transition at . The maximum broadening which would still allow mass twin compact stars is found to be for all parametrizations within the present class of models. At least the heavier of the neutron stars of the binary merger GW170817 could have been a member of the third family of hybrid stars.

    Comments:
    8 pages, 8 figures, revised version as published in Phys. Rev. D, references updated
    Subjects:
    Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE); High Energy Physics — Phenomenology (hep-ph)
    arXiv:
    1711.03926 [pdf]
    PRC(2018)·58 citations
  6. 06

    [Submitted on 10 Nov 2017] (cross-list from physics.atom-ph)

    Probing "long-range" neutrino-mediated forces with atomic and nuclear spectroscopy

    Yevgeny V. Stadnik

    The exchange of a pair of low-mass neutrinos between electrons, protons and neutrons produces a "long-range" potential, which can be sought for in phenomena originating on the atomic and sub-atomic length scales. We calculate the effects of neutrino-pair exchange on transition and binding energies in atoms and nuclei. In the case of atomic s-wave states, there is a large enhancement of the induced energy shifts due to the lack of a centrifugal barrier and the highly singular nature of the neutrino-mediated potential. We derive limits on neutrino-mediated forces from measurements of the deuteron binding energy and transition energies in positronium, muonium, hydrogen and deuterium, as well as isotope-shift measurements in calcium ions. Our limits improve on existing constraints on neutrino-mediated forces from experiments that search for new macroscopic forces by 18 orders of magnitude. Future spectroscopy experiments have the potential to probe long-range forces mediated by the exchange of pairs of standard-model neutrinos and other weakly-charged particles.

    Comments:
    6 pages, 1 figure, version accepted to PRL
    Subjects:
    Atomic Physics (physics.atom-ph); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1711.03700 [pdf]
    PRL(2018)·57 citations
  7. 07

    [Submitted on 10 Nov 2017] (cross-list from hep-ph)

    Quantum Chromodynamics at small Bjorken-x

    Pieter Taels🇧🇪

    With the advent of very powerful particle accelerators, such as RHIC and the LHC, it becomes possible to study QCD in high energy collisions, in which the gluon content of the proton or nucleus is probed and its density becomes often large enough for nonlinear effects to play a role. This small-x regime of QCD is well described by an effective theory known as the Color Glass Condensate (CGC). In this thesis, we introduce the CGC and apply it to two different problems. First, we use the CGC to study forward heavy-quark production in pA collisions. When the quarks are nearly back-to-back, the CGC result coincides with the one in the TMD factorization approach. This allows us to extract the small-x limit of the Weizsäcker-Williams gluon distribution, as well as the dipole distribution and one extra gluon TMD. Each of these gluon TMDs is accompanied by a partner, which couples via the quark mass and which describes the linearly polarized gluon content of the unpolarized nucleus. We calculate the six resulting gluon TMDs analytically in the MV model, and evolve them in rapidity using a numerical implementation of JIMWLK. The second problem is situated within heavy-ion physics. Jets, produced in the scattering of two nuclei, travel through the Quark-Gluon Plasma (QGP) before reaching the detector, and are attenuated as a result of their interaction with this medium. This phenomenon, known as jet quenching, is one of the main probes to investigate the QGP. We focus on the transverse momentum broadening of a hard particle traveling through a nuclear medium, and employ small-x techniques to attempt to resum the leading logarithmic corrections due to soft gluon radiation. Although, ultimately, we can only solve the resulting in-medium evolution equation to DLA accuracy, we do present a concise framework for the problem, and draw a detailed comparison with the CGC and with the literature.

    Comments:
    PhD thesis, defended at the University of Antwerp, Belgium, on July 3, 2017
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1711.03928 [pdf]
    8 citations

Affiliations

first authorsco-authorsvia INSPIRE