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Nuclear Theory·nucl-th

Tuesday·September 25, 2018

14 papers—8 primary·6 cross-listed

All14Primary8Cross-lists6
  1. 09

    Magnetic field-dependence of the neutral pion mass in the linear sigma model coupled to quarks: The weak field case

    Alejandro Ayala🇲🇽 · Ricardo L. S. Farias🇧🇷 · S. Hernandez-Ortiz🇲🇽 · Luis A. Hernandez🇲🇽 · D. Manreza Paret🇲🇽 · R. Zamora🇨🇱

    We compute the neutral pion mass dependence on a magnetic field in the weak field approximation at one-loop order. The calculation is carried out within the linear sigma model coupled to quarks and using Schwinger's proper-time representation for the charged particle propagators. We find that the neutral pion mass decreases with the field strength provided the boson self-coupling magnetic field corrections are also included. The calculation should be regarded as the setting of the trend for the neutral pion mass as the magnetic field is turned on.

    ↳ hep-phhep-thnucl-thPRD(2018)·66 citations
  2. 10

    Charged-current scattering off O nucleus as a detection channel for supernova neutrinos

    Ken'ichiro Nakazato🇯🇵 · Toshio Suzuki🇯🇵 · Makoto Sakuda🇯🇵

    Event spectra of the neutrino-O charged-current reactions in Super-Kamiokande are evaluated for a future supernova neutrino burst. Since these channels are expected to be useful for diagnosing a neutrino spectrum with high average energy, the evaluations are performed not only for an ordinary supernova neutrino model but also for a model of neutrino emission from a black-hole-forming collapse. Using shell model results, whose excitation energies are consistent with the experimental data, the cross sections of the O()X and O()X reactions for each nuclear state with a different excitation energy are employed in this study. It is found that, owing to the components of the reaction with higher excitation energy, the event spectrum becomes 4-7 MeV softer than that in the case without considering the excitation energies. In addition, a simplified approach to evaluate the event spectra is proposed for convenience and its validity is examined.

    ↳ astro-ph.HEhep-phnucl-thPTEP(2018)·22 citations
  3. 11

    Effect of limited statistics on higher order cumulants measurement in heavy-ion collision experiments

    Ashish Pandav🇮🇳 · Debasish Mallick🇮🇳 · Bedangadas Mohanty🇮🇳

    We have studied the effect of limited statistics of data on measurement of the different order of cumulants of net-proton distribution assuming that the proton and antiproton distributions follow Possionian and Binomial distributions with initial parameters determined from experimental results for two top center of mass energies ( and GeV) in most central (%) AuAu collisions at Relativistic Heavy Ion Collider (RHIC). In this simulation, we observe that the central values for higher order cumulants have a strong dependence on event sample size and due to statistical randomness the central values of higher order cumulants could become negative. We also present a study on the determination of the statistical error on cumulants using delta theorem, bootstrap and sub-group methods and verified their suitability by employing a Monte Carlo procedure. Based on our study we find that the bootstrap method provides a robust way for statistical error estimation on high order cumulants. We also present the exclusion limits on the minimum event statistics needed for determination of cumulants if the signal strength (phase transition or critical point) is at a level of % and % above the statistical level. This study will help the experiments to arrive at the minimum required event statistics and choice of proper method for statistical error estimation for high order cumulant measurements.

    ↳ nucl-exhep-exnucl-thNPA(2019)·28 citations
  4. 12

    Strange Nuclear Physics from QCD on Lattice

    Takashi Inoue (for HAL QCD Collaboration)🇯🇵

    We study single-particle potential of Lambda, Sigma, and Xi hyperons in nucleonic matter starting from the fundamental theory of the strong interaction, QCD. First we carry out a lattice QCD numerical simulation, and extract baryon-baryon interactions from QCD by means of the HAL QCD method. We employ a full QCD gauge configuration ensemble at almost physical point so that we can study the physical world, hence mass of hadrons are nearly physical, for example, pion mass is 146 MeV, kaon mass is 525 MeV, and nucleon mass is 958 MeV. Then, we apply the obtained hyperon interactions to the Brueckner-Hartree-Fock many-nucleon theory, and calculate single-particle potential of hyperons in nucleonic matter U_{Y}(k). We obtain for hyperons stopping in the symmetric nuclear matter at the normal nuclear matter density, U_{Lambda}(0)=-28 MeV, U_{Sigma}(0)=+15 MeV, and U_{Xi}(0)=-4 MeV with a statistical error about +/- 2 MeV associated with our Monte Carlo simulation. These results are qualitatively compatible with values suggested from hypernuclear experiments. This success is remarkable and very encouraging since this proves that our approach to strange nuclear physics starting from QCD is essentially correct.

    ↳ hep-lathep-phnucl-exnucl-thAIP Conf.Proc.(2019)·47 citations
  5. 13

    Efimov states of three unequal bosons in non-integer dimensions

    E.R. Christensen · A.S. Jensen · E. Garrido

    The Efimov effect for three bosons in three dimensions requires two infinitely large -wave scattering lengths. We assume two identical particles with very large scattering lengths interacting with a third particle. We use a novel mathematical technique where the centrifugal barrier contains an effective dimension parameter, which allows efficient calculations precisely as in ordinary three spatial dimensions. We investigate properties and occurrence conditions of Efimov states for such systems as functions of the third scattering length, the non-integer dimension parameter, mass ratio between unequal particles, and total angular momentum. We focus on the practical interest of the existence, number of Efimov states and their scaling properties. Decreasing the dimension parameter from towards the Efimov effect and states disappear for critical values of mass ratio, angular momentum and scattering length parameter. We investigate the relations between the four variables and extract details of where and how the states disappear. Finally, we supply a qualitative relation between the dimension parameter and an external field used to squeeze a genuine three dimensional system.

    ↳ physics.atm-clusnucl-thFew Body Syst.(2018)·11 citations
  6. 14

    Deciphering the coalescence behavior of Coulomb-Schrödinger atomic wave functions from an operator product expansion

    Yingsheng Huang🇨🇳 · Yu Jia🇨🇳 · Rui Yu🇨🇳

    We revisit the coalescence behavior of the atomic Schrödinger wave functions from the angle of an operator product expansion (OPE) within the nonrelativistic Coulomb-Schrödinger effective field theory. We take the electron-nucleus coalescence as an explicit example to demonstrate our formalism, where the celebrated Kato's cusp condition can be easily reproduced. An exact OPE relation is rigorously proved to all orders in perturbation theory. Our approach can be readily extended to ascertain the multi-particle coalescence behaviors of atomic wave functions, as well as to take relativistic effects into account.

    ↳ hep-phnucl-thphysics.atom-phphysics.chem-phPRA(2025)·3 citations

Affiliations

first authorsco-authorsvia INSPIRE