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Nuclear Theory·nucl-th

Thursday·January 12, 2023

10 papers—5 primary·5 cross-listed

All10Primary5Cross-lists5
  1. 06

    Scattering Amplitude from Quantum Computing with Reduction Formula

    Tianyin Li🇨🇳 · Wai Kin Lai🇨🇳 · Enke Wang🇨🇳 · Hongxi Xing🇨🇳

    Utilizing the Lehmann-Symanzik-Zimmermann reduction formula, we present a new general framework for computing scattering amplitudes in quantum field theory with quantum computers in a fully nonperturbative way. In this framework, one only has to construct one-particle states of zero momentum, and no wave packets of incoming particles are needed. The framework is able to incorporate scatterings of bound states, and is ideal for scatterings involving a small number of particles. We expect this framework to have particular advantages when applied to exclusive hadron scatterings. As a proof of concept, by simulations on classical hardware, we demonstrate that in the one-flavor Gross-Neveu model, the fermion propagator, the connected fermion four-point function, and the propagator of a fermion-antifermion bound state obtained from our proposed quantum algorithm have the desired pole structure crucial to the implementation of the Lehmann-Symanzik-Zimmermann reduction formula.

    ↳ hep-phhep-exnucl-thquant-phPRD(2024)·23 citations
  2. 07

    Speed of sound in QCD matter at finite temperature and density]{Speed of sound in QCD matter at finite temperature and density

    Gun-yun Shao🇨🇳 · Xin-ran Yang🇨🇳 · Chong-long Xie🇨🇳 · Wei-bo He🇨🇳

    The speed of sound in QCD matter at finite temperature and density is investigated within the Polyakov loop improved Nambu--Jona-Lasinio (PNJL) model. The spinodal structure associated with the chiral first-order chiral phase transition is considered to describe the continuous variation of the speed of sound. The behaviors of the squared sound speed in different phases, including the stable, metastable and unstable phases, are derived. The relation between speed of sound and QCD phase transitions is systematically explored. In particular, the boundary of vanishing sound velocity is derived in the temperature-density phase diagram, and the region where the sound wave equation being broken is pointed out. Some interesting features of speed of sound under different definitions are also discussed.

    ↳ hep-phnucl-thEur.Phys.J.Plus(2023)·3 citations
  3. 08

    Self-consistent thermodynamic potential for magnetized QCD matter

    Gaoqing Cao🇨🇳 · Jianing Li🇨🇳

    Within the two-flavor Nambu--Jona-Lasinio model, we derive a self-consistent thermodynamic potential for a QCD matter in an external magnetic field . To be consistent with Schwinger's renormalization spirit, counter terms with vacuum quark mass are introduced into and then the explicit -dependent parts can be regularized in a cutoff-free way. Following that, explicit expressions of gap equation and magnetization can be consistently obtained according to the standard thermodynamic relations. The formalism is able to reproduce the paramagnetic feature of a QCD matter without ambiguity. For more realistic study, a running coupling constant is also adopted to account for the inverse magnetic catalysis effect. It turns out that the running coupling would greatly suppress magnetization at large and is important to reproduce the temperature enhancement effect to magnetization. The case with finite baryon chemical potential is also explored: no sign of first-order transition is found by varying for the running coupling and the de Haas-van Alphen oscillation shows up in the small region.

    ↳ hep-phnucl-thPRD(2023)·6 citations
  4. 09

    Phase Transitions in Particle Physics -- Results and Perspectives from Lattice Quantum Chromo-Dynamics

    Gert Aarts🇬🇧 · Joerg Aichelin🇫🇷 · Chris Allton🇬🇧 · Andreas Athenodorou🇮🇹 · Dimitrios Bachtis🇬🇧 · Claudio Bonanno🇮🇹 · Nora Brambilla🇩🇪 · Elena Bratkovskaya🇩🇪 · Mattia Bruno🇮🇹 · Michele Caselle🇮🇹 · Costanza Conti🇮🇹 · Roberto Contino🇮🇹 and 29 other authors

    Phase transitions in a non-perturbative regime can be studied by ab initio Lattice Field Theory methods. The status and future research directions for LFT investigations of Quantum Chromo-Dynamics under extreme conditions are reviewed, including properties of hadrons and of the hypothesized QCD axion as inferred from QCD topology in different phases. We discuss phase transitions in strong interactions in an extended parameter space, and the possibility of model building for Dark Matter and Electro-Weak Symmetry Breaking. Methodological challenges are addressed as well, including new developments in Artificial Intelligence geared towards the identification of different phases and transitions.

    ↳ hep-lathep-phhep-thnucl-thPPNP(2023)·152 citations
  5. 10

    Point Production of a Nonrelativistic Unparticle Recoiling Against a Particle

    Eric Braaten🇺🇸 · Hans-Werner Hammer🇩🇪

    A nonrelativistic unparticle can be defined as an excitation created by an operator with a definite scaling dimension in a nonrelativistic field theory with an approximate conformal symmetry. The point production rate of an unparticle has power-law dependence on its total energy with an exponent determined by its scaling dimension. We use the exact result for the 3-point function of primary operators in a nonrelativistic conformal field theory to derive the contribution to the point production rate of the unparticle from its decay into another unparticle recoiling against a particle. In the case where the conformal symmetry is broken by a large positive scattering length, we deduce the exponent of the energy in the point production rate of the loosely bound two-particle state recoiling against a particle with large relative momentum.

    ↳ hep-thhep-phnucl-thPRD(2023)·6 citations

Affiliations

first authorsco-authorsvia INSPIRE