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Nuclear Theory·nucl-th

Tuesday·November 19, 2019

14 papers—8 primary·6 cross-listed

All14Primary8Cross-lists6
  1. 09

    [Submitted on 15 Nov 2019] (cross-list from hep-ph)

    Calculating the angle between jet axes

    Pedro Cal🇳🇱 · Duff Neill🇺🇸 · Felix Ringer🇺🇸 · Wouter J. Waalewijn🇳🇱

    We study the angle between i) the standard jet axis, ii) the axis of a jet which has been groomed using soft drop, with reduced sensitivity to soft radiation, iii) the jet axis obtained with the winner-take-all recombination scheme, which is insensitive to soft radiation at leading power. We calculate the distributions for these angles at next-to-leading logarithmic accuracy, including non-global logarithms. The angle between the standard and groomed jet axis directly probes soft wide-angle radiation, leading to a novel factorization formula. This angle is also very sensitive to nonperturbative physics, which is directly connected to nonperturbative contribution to the rapidity anomalous dimension for transverse momentum distributions. Comparing our predictions to Pythia we find good agreement, and we foresee applications to jet substructure in proton-proton and heavy ion collisions.

    Comments:
    39 pages, 13 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    1911.06840 [pdf]
    JHEP(2020)·42 citations
  2. 10

    [Submitted on 16 Nov 2019] (cross-list from gr-qc)

    Studying strong phase transitions in neutron stars with gravitational waves

    Katerina Chatziioannou🇺🇸 · Sophia Han🇺🇸

    The composition of neutron stars at the extreme densities reached in their cores is currently unknown. Besides nuclear matter of normal neutrons and protons, the cores of neutron stars might harbor exotic matter such as deconfined quarks. In this paper we study strong hadron-quark phase transitions in the context of gravitational wave observations of inspiraling neutron stars. We consider upcoming detections of neutron star coalescences and model the neutron star equations of state with phase transitions through the Constant-Speed-of-Sound parametrization. We use the fact that neutron star binaries with one or more hadron-quark hybrid stars can exhibit qualitatively different tidal properties than binaries with hadronic stars of the same mass, and hierarchically model the masses and tidal properties of simulated populations of binary neutron star inspiral signals. We explore the parameter space of phase transitions and discuss under which conditions future observations of binary neutron star inspirals can identify this effect and constrain its properties, in particular the threshold density at which the transition happens and the strength of the transition. We find that if the detected population of binary neutron stars contains both hadronic and hybrid stars, the onset mass and strength of a sufficiently strong phase transition can be constrained with 50-100 detections. If the detected neutron stars are exclusively hadronic or hybrid, then it is possible to place lower or upper limits on the transition density and strength.

    Comments:
    21 pages, 13 figures, 3 tables; accepted for publication in PRD, discussion on softer quark matter added, typos corrected
    Subjects:
    General Relativity and Quantum Cosmology (gr-qc); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    1911.07091 [pdf]
    PRD(2020)·105 citations
  3. 11

    [Submitted on 16 Nov 2019] (cross-list from hep-ph)

    QGP droplet formation in small asymmetric collision systems

    Thomas A. Trainor🇺🇸

    The journal Nature recently published a letter titled "Creating small circular, elliptical, and triangular droplets of quark-gluon plasma" [1]. The basis for that claim is a combination of measured Fourier amplitudes and from collision systems -Au, -Au and -Au (helion is the nucleus of atom He), Glauber Monte Carlo estimates of initial-state transverse collision geometries for those systems and hydro Monte Carlo descriptions of the data. Correspondence between hydro trends and data trends is interpreted as confirmation of "collectivity" occurring in the small collision systems, further interpreted to indicate QGP formation. QGP formation in small systems runs counter to pre-RHIC theoretical assumptions that QGP formation should require large collision systems (e.g. central A-A collisions). There is currently available a broad context of experimental data from -, A-A and -Pb collisions at the RHIC and LHC against which the validity of the Nature letter claims may be evaluated. This talk provides a summary of such results and their implications. [1] Nature Phys. 15, no. 3, 214 (2019).}

    Comments:
    6 pages, 6 figures, Proceedings of XLIX International Symposium on Multiparticle Dynamics (ISMD 2019)
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1911.07094 [pdf]
    EPJ Web Conf.(2020)·1 citation
  4. 12

    [Submitted on 17 Nov 2019] (cross-list from astro-ph.HE)

    Properties of binary components and remnant in GW170817 using equations of state in finite temperature field theory models

    Shriya Soma · Debades Bandyopadhyay

    We investigate gross properties of binary components and remnant in GW170817 using equations of state within the finite temperature field theoretical models. We also adopt finite temperature equations of state in the density dependent hadron field theory for this study. Properties of binary components are studied using zero temperature equations of state. Particularly, we investigate tidal deformabilities and radii of binary components in light of GW170817. An analytical expression relating the radii and the combined tidal deformability is obtained for binary neutron star masses in the range . The upper bound on the tidal deformability gives the upper bound on the neutron star radius as 13 km. Next, the role of finite temperature on the remnant in GW170817 is explored. In this case, we investigate the gravitational and baryon mass, radius, Kepler frequency and moment of inertia of the rigidly rotating remnant for different equations of state at fixed entropy per baryon. The remnant radius is enlarged due to thermal effects compared with the zero temperature case. Consequently, it is found that the Kepler frequency is much lower at higher entropy per baryon than that of the case at zero temperature. These findings are consistent with the results found in the literature.

    Comments:
    LaTex, 17 pages including 7 Figures; title is slightly modified and article is revised
    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    1911.07332 [pdf]
    ApJ(2020)·15 citations
  5. 13

    [Submitted on 18 Nov 2019] (cross-list from hep-ph)

    Excitation functions of related parameters from transverse momentum (mass) spectra in high energy collisions

    Li-Li Li🇨🇳 · Fu-Hu Liu🇨🇳 · Muhammad Waqas🇨🇳 · Rasha Al-Yusufi🇨🇳 · Altaf Mujear🇨🇳

    Transverse momentum (mass) spectra of positively and negatively charged pions, positively and negatively charged kaons, protons and antiprotons produced at mid-(pseudo)rapidity in various collisions at high energies are analyzed in this work. The experimental data measured in central gold-gold, central lead-lead, and inelastic proton-proton collisions by several international collaborations are studied. The (two-component) standard distribution is used to fit the data and extract the excitation function of effective temperature. Then, the excitation functions of kinetic freeze-out temperature, transverse flow velocity, and initial temperature are obtained. In the considered collisions, the four parameters increase with the increase of collision energy in general, and the kinetic freeze-out temperature appears the trend of saturation at the top Relativistic Heavy Ion Collider and the Large Hadron Collider.

    Comments:
    20 pages, 6 figures. Advances in High Energy Physics, accepted
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1911.07419 [pdf]
    Adv.High Energy Phys.(2020)·15 citations
  6. 14

    [Submitted on 18 Nov 2019] (cross-list from astro-ph.HE)

    Co-production of light and heavy -process elements via fission deposition

    Nicole Vassh · Matthew R. Mumpower · Gail C. McLaughlin · Trevor M. Sprouse · Rebecca Surman

    We apply for the first time fission yields determined across the chart of nuclides from the macroscopic-microscopic theory of the Finite Range Liquid Drop Model to simulations of rapid neutron capture (-process) nucleosynthesis. With the fission rates and yields derived within the same theoretical framework utilized for other relevant nuclear data, our results represent an important step toward self-consistent applications of macroscopic-microscopic models in -process calculations. The yields from this model are wide for nuclei with extreme neutron excess. We show that these wide distributions of neutron-rich nuclei, and particularly the asymmetric yields for key species that fission at late times in the process, can contribute significantly to the abundances of the lighter heavy elements, specifically the light precious metals palladium and silver. Since these asymmetric yields correspondingly also deposit into the lanthanide region, we consider the possible evidence for co-production by comparing our nucleosynthesis results directly with the trends in the elemental ratios of metal-poor stars rich in -process material. We show that for -process enhanced stars palladium over europium and silver over europium display mostly flat trends suggestive of co-production and compare to the lanthanum over europium trend which is often used to justify robustness arguments in the lanthanide region. We find that such robustness arguments may be extendable down to palladium and heavier and demonstrate that fission deposition is a mechanism by which such a universality or robustness can be achieved.

    Subjects:
    High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    1911.07766 [pdf]
    ApJ(2020)·38 citations

Affiliations

first authorsco-authorsvia INSPIRE