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Nuclear Theory·nucl-th

Tuesday·May 7, 2019

13 papers—6 primary·7 cross-listed

All13Primary6Cross-lists7
  1. 07

    [Submitted on 4 May 2019] (cross-list from nucl-ex)

    Ne level structure in the resonance O+ elastic scattering

    A. K. Nurmukhanbetova · V. Z. Goldberg · D. K. Nauruzbayev · M. S. Golovkov · A. Volya

    The first study of resonances in O+ elastic scattering was carried out using the Thick Target Inverse Kinematics (TTIK) method. The data were analyzed in the framework of an -matrix approach. Many -cluster states were found in the Ne excitation region of the 9-13 MeV excitation energy including the first observation of a broad =0 state in an odd-even nucleus, which is likely the analog of the broad 0 at 8 MeV in Ne. The observed structure in Ne appeared to be strikingly similar to that in Ne populated in the resonance O+ scattering. The results are also useful for refinement of data on an O(,) reaction important for astrophysics.

    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1905.01461 [pdf]
    PRC(2019)·10 citations
  2. 08

    [Submitted on 6 May 2019] (cross-list from hep-ph)

    Estimating the variation of neutron star observables by symmetric dense nuclear matter properties

    Péter Pósfay🇭🇺 · Gergely Gábor Barnaföldi🇭🇺 · Antal Jakovác🇭🇺

    Recent multi-channel astrophysics observations and the soon-to-be published new measured electromagnetic and gravitation data provide information on the inner structure of the compact stars. These macroscopic observations can significantly increase our knowledge on the neutron star enteriors, providing constraints on the microscopic physical properties. On the other hand, due to the masquarade problem, there are still uncertainties on the various nuclear-matter models and their parameters as well. Calculating the properties of the dense nuclear matter, effective field theories are the most widely-used tools. However the values of the microscopical parameters need to be set consistently to the nuclear and astrophysical measurements. In this work we investigate how uncertainties are induced by the variation of the microscopical parameters. We use a symmetric nuclear matter in an extended - model. We calculate the dense matter equation of state and give the mass-radius diagram. We present that the Landau mass and compressibility modulus of the nuclear matter have definite linear relation to the maximum mass of a Schwarzschild neutron star.

    Comments:
    14 pages, 5 figures 2 tables
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Astrophysical Phenomena (astro-ph.HE); Nuclear Theory (nucl-th)
    arXiv:
    1905.01872 [pdf]
    Universe(2019)·7 citations
  3. 09

    [Submitted on 6 May 2019] (cross-list from hep-ph)

    Operator Relations for Gravitational Form Factors

    Kazuhiro Tanaka (Juntendo Univ.)🇯🇵

    The form factors for the hadron matrix element of the QCD energy-momentum tensor not only describe the coupling of the hadron with a graviton as the ``gravitational form factors'', but also serve as unique quantities for describing the shape inside the hadron reflecting dynamics of quarks and gluons, such as the internal shear forces acting on the quarks/gluons and their pressure distributions. We consider the gravitational form factors for a hadron, in particular, for a (pseudo)scalar hadron and for the nucleon. We derive and clarify the relations satisfied by the gravitational form factors as direct consequences of the symmetries and the equations of motion in QCD, and connections to the generalized parton distributions. Our results reveal that the gravitational form factors are related to the higher-twist quark-gluon correlation effects inside the hadrons and also to QCD trace anomaly.

    Comments:
    4 pages. To appear in the proceedings of 8th International Conference on Quarks and Nuclear Physics (QNP2018), November 13-17, 2018, Tsukuba, Japan
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1905.01934 [pdf]
    JPS Conf.Proc.(2019)·1 citation
  4. 10

    [Submitted on 6 May 2019] (cross-list from hep-ph)

    Unified Analyses of Multiplicity Distributions and Bose-Einstein Correlations at the LHC using Double-Stochastic Distributions

    Takuya Mizoguchi🇯🇵 · Minoru Biyajima🇯🇵

    We analyze data on multiplicity distributions (MD) at Large Hadron Collider (LHC) energies using a double-negative binomial distribution (D-NBD) and double-generalized Glauber-Lachs formula (D-GGL). Moreover, we investigate the Bose-Einstein correlation (BEC) formulas based on these distributions and analyze the BEC data using the parameters obtained by analysis of MDs. From these analyses it can be inferred that the D-GGL formula performs as effectively as the D-NBD. Moreover, our results show that the parameters estimated in MD are related to those contained in the BEC formula.

    Comments:
    8th International Conference on Quarks and Nuclear Physics, To be appeared in JPS Conf. Proc. (2019)
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1905.02042 [pdf]
    JPS Conf.Proc.(2019)·5 citations
  5. 11

    [Submitted on 6 May 2019] (cross-list from nucl-ex)

    First observation of the directed flow of and in Au+Au collisions at = 200~GeV

    STAR Collaboration: J. Adam🇺🇸 · L. Adamczyk🇵🇱 · J. R. Adams🇺🇸 · J. K. Adkins🇺🇸 · G. Agakishiev🇷🇺 · M. M. Aggarwal🇮🇳 · Z. Ahammed🇮🇳 · I. Alekseev🇷🇺 · D. M. Anderson🇺🇸 · R. Aoyama🇯🇵 · A. Aparin🇷🇺 · D. Arkhipkin🇺🇸 and 339 other authors

    We report the first measurement of rapidity-odd directed flow () for and mesons at mid-rapidity () in Au+Au collisions at = 200\,GeV using the STAR detector at the Relativistic Heavy Ion Collider. In 10--80\% Au+Au collisions, the slope of the rapidity dependence (), averaged over and mesons, is -0.080 0.017 (stat.) 0.016 (syst.) for transverse momentum above 1.5~GeV/. The absolute value of -meson is about 25 times larger than that for charged kaons, with 3.4 significance. These data give a unique insight into the initial tilt of the produced matter, and offer constraints on the geometric and transport parameters of the hot QCD medium created in relativistic heavy-ion collisions.

    Comments:
    Submitted to Phys. Rev. Lett
    Subjects:
    Nuclear Experiment (nucl-ex); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
    arXiv:
    1905.02052 [pdf]
    PRL(2019)·140 citations
  6. 12

    [Submitted on 6 May 2019] (cross-list from hep-lat)

    Magnetized baryons and the QCD phase diagram: NJL model meets the lattice

    Gergely Endrődi🇩🇪 · Gergely Markó🇭🇺

    We determine the baryon spectrum of 1 + 1 + 1-flavor QCD in the presence of strong background magnetic fields using lattice simulations at physical quark masses for the first time. Our results show a splitting within multiplets according to the electric charge of the baryons and reveal, in particular, a reduction of the nucleon masses for strong magnetic fields. This first-principles input is used to define constituent quark masses and is employed to set the free parameters of the Polyakov loop-extended Nambu-Jona-Lasinio (PNJL) model in a magnetic field-dependent manner. The so constructed model is shown to exhibit inverse magnetic catalysis at high temperatures and a reduction of the transition temperature as the magnetic field grows - in line with non-perturbative lattice results. This is contrary to the naive variant of this model, which gives incorrect results for this fundamental phase diagram. Our findings demonstrate that the magnetic field dependence of the PNJL model can be reconciled with the lattice findings in a systematic way, employing solely zero-temperature first-principles input.

    Comments:
    14 pages, 7 figures, updatet some figures, included new references and a table of key results
    Subjects:
    High Energy Physics — Lattice (hep-lat); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    1905.02103 [pdf]
    JHEP(2019)·70 citations
  7. 13

    [Submitted on 6 May 2019] (cross-list from nucl-ex)

    Comment on "Searching for flavor dependence in nuclear quark behavior"

    O. Hen🇺🇸 · F. Hauenstein🇺🇸 · D.W. Higinbotham🇺🇸 · G.A. Miller🇺🇸 · E. Piasetzky🇮🇱 · A. Schmidt🇺🇸 · E.P. Segarra🇺🇸 · M. Strikman🇺🇸 · L.B. Weinstein🇺🇸

    Weinstein, et. al [1] [PRL 106, 052301 (2011)] and Hen, et. al [2] [PRC 85, 047301 (2012)] observed a correlation between the EMC effect and the amount of short range correlated (SRC) pairs in nuclei which implies that quark distributions are different in SRC pairs as compared with free nucleons. Schmookler, et. al [3] [Nature 566, 354 (2019)] bolstered this by showing that the EMC data can be explained by a universal modification of the structure of nucleons in neutron-proton SRC pairs and presented the first data-driven extraction of this universal modification function (UMF). Arrington and Fomin [4] [arxiv 1903.12535] attempt to gain insight into the correlation between the EMC effect and SRCs by distinguishing between correlated nucleon pairs at high-virtuality (HV) vs. high local-density (LD). However, there is an inconsistency in their derivations of the UMFs, FLD univ and FHV , causing a non-physical difference between them for asymmetric nuclei. In addition, the univ combinatorial scaling they used to extract high-LD np, pp and nn pairs from measured HV np pairs is contradicted by realistic ab-initio Quantum Monte-Carlo (QMC) calculations.

    Subjects:
    Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    1905.02172 [pdf]
    7 citations

Affiliations

first authorsco-authorsvia INSPIRE