PaperPanorama

Nuclear Theory·nucl-th

Wednesday·June 19, 2024

9 papers6 primary·3 cross-listed

  1. 07

    Study on relativistic transformations for thermodynamic quantities: Boltzmann-Gibbs and Tsallis blast-wave models

    A.S. Parvan🇷🇺

    This study derives the relativistic transformations of thermodynamic quantities from the Lorentz transformations applied to the four-momentum components of a thermodynamic system, which is stationary in the inertial reference frame and moves at constant velocity relative to the laboratory frame . Thermodynamic variables are introduced into the formalism via the zeroth component of the four-momentum in , representing the system's internal energy. By treating the three-momentum as an independent state variable, thermodynamic quantities are defined by differentiating the zeroth component of the four-momentum (the Hamiltonian) in the reference frame with respect to the independent state variables, yielding the fundamental thermodynamic potential. This approach results in the Non-Planck transformations, which differ from the Planck transformations by a factor of . In contrast, by adopting the three-velocity as an independent state variable, thermodynamic quantities are obtained by differentiating the negative Lagrangian, derived from the zeroth component of the four-momentum via Legendre transformations, with respect to the independent state variables, producing the conjugate fundamental thermodynamic potential. This yields the Planck transformations. Conversely, the Ott transformations are derived from the zeroth component of the four-momentum by treating velocity as an independent state variable. This approach conflicts with the principles of mechanics, resulting in an energy that does not qualify as a thermodynamic potential. To validate these findings, we analyze an ultrarelativistic ideal gas of quarks and gluons within the Stefan-Boltzmann limit. Furthermore, we develop consistent Boltzmann-Gibbs and Tsallis blast-wave models for finite-volume freeze-out firecylinders in heavy ion collisions, incorporating Planck and Ott transformations.

    hep-phnucl-thEPJA(2025)·0 citations
  2. 08

    Spin-independent interactions of Dirac Fermionic Dark Matter in the composite Higgs models

    M. G. Belyakova🇷🇺 · R. Nevzorov🇷🇺

    According to recent measurements, dark matter magnetic dipole moment is strongly constrained. In the composite Higgs models the magnetic dipole moment of the Dirac dark matter fermion and its mass can be suppressed by the approximate U(1) symmetry. We consider E_6 inspired composite Higgs model (E_6CHM) with U(1) symmetry violating operators, which give rise to dark matter's mass and coupling constant to Higgs boson. The dependence of the spin-independent dark matter-nucleon scattering cross section on the E_6CHM parameters is explored. We argue that there are regions of the parameter space which are still safe from all current constraints and may lead to spectacular LHC signatures.

    hep-phastro-ph.COhep-exhep-th+1PRD(2024)·4 citations
  3. 09

    Neural Ordinary Differential Equations for Mapping the Magnetic QCD Phase Diagram via Holography

    Rong-Gen Cai🇨🇳 · Song He🇨🇳 · Li Li🇨🇳 · Hong-An Zeng🇨🇳

    The QCD phase diagram is crucial for understanding strongly interacting matter under extreme conditions, with major implications for cosmology, neutron stars, and heavy-ion collisions. We present a novel holographic QCD model utilizing neural ordinary differential equations (ODEs) to map the QCD phase diagram under magnetic field , baryon chemical potential , and temperature . By solving the inverse problem of constructing a gravitational theory from Lattice QCD data, we reveal an unprecedentedly rich phase structure at finite , including multiple critical endpoints (CEPs) in strong magnetic fields. Specifically, for { Gauss}, we identify two distinct CEPs at and . Notably, the critical exponents vary depending on the CEP's location, and the conventional scaling relations can be violated in the presence of strong magnetic fields. These findings significantly advance our understanding of the QCD phase structure and provide concrete predictions for experimental validation at upcoming facilities such as FAIR, JPARC-HI, and NICA.

    hep-thgr-qchep-phnucl-thSCPMA(2026)·43 citations

Affiliations

first authorsco-authorsvia INSPIRE