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Nuclear Theory·nucl-th

Thursday·May 20, 2021

9 papers—6 primary·3 cross-listed

All9Primary6Cross-lists3
  1. 07

    [Submitted on 19 May 2021] (cross-list from hep-ph)

    Reentrant pion superfluidity and cosmic trajectories within PNJL model

    Gaoqing Cao🇨🇳 · Lianyi He🇨🇳 · Pengming Zhang🇨🇳

    In this work, we self-consistently explore the possibility of charged pion superfluidity and cosmic trajectories in early Universe under the framework of Polyakov-Nambu--Jona-Lasinio model. By taking the badly constrained lepton flavor asymmetries and as free parameters, the upper boundaries of pion superfluidity phase are consistently found to be around the pseudocritical temperature at zero chemical potentials. So the results greatly support the choice of as the upper boundary of pion superfluidity in the previous lattice QCD study. Take as an example, we demonstrate the features of pion condensation and the associated cosmic trajectories with the evolution of early Universe. While the trajectory of electric chemical potential reacts strongly at both the lower and upper boundaries of reentrant pion superfluidity, the trajectories of other chemical potentials only respond strongly at the upper boundary.

    Subjects:
    High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
    arXiv:
    2105.08932 [pdf]
    PRD(2021)·13 citations
  2. 08

    [Submitted on 19 May 2021] (cross-list from cond-mat.quant-gas)

    Recombination in the universal four-fermion system

    A. Deltuva🇱🇹

    In the systems of spin fermions with resonant -wave interactions supporting only weakly bound dimers the antisymmetry forbids recombination of three (or more) fermions at zero energy. However, the fermion-fermion-dimer recombination is only partially suppressed. It is studied in the framework of momentum-space integral equations for the four-particle transition operators. In the vicinity of the unitary limit the fermion-fermion-dimer recombination rate, rescaled to build dimensionless quantity, is found to be linear in the effective range parameter, enabling a simple and accurate parametrization as well as evaluation of finite-range effects for any potential model. This feature makes the present results very useful in benchmarking different methods for three-cluster breakup and recombination calculations in four-particle systems. The interplay of the three-fermion and fermion-fermion-dimer recombination processes and their consequences for ultracold mixtures of fermions and dimers is discussed.

    Comments:
    modified definition of the recombination rate
    Subjects:
    Quantum Gases (cond-mat.quant-gas); Nuclear Theory (nucl-th); Atomic Physics (physics.atom-ph)
    arXiv:
    2105.09033 [pdf]
    PLB(2021)·0 citations
  3. 09

    [Submitted on 19 May 2021] (cross-list from hep-ph)

    Heavy baryon spectrum with chiral multiplets of scalar and vector diquarks

    Yonghee Kim🇯🇵 · Yan-Rui Liu🇨🇳 · Makoto Oka🇯🇵 · Kei Suzuki🇯🇵

    Chiral effective theory of scalar and vector diquarks is formulated according to the linear sigma model. The main application is to describe the ground and excited states of singly heavy baryons with a charm or bottom quark. Applying the potential quark model between the diquark and the heavy quark (), we construct a heavy-quark--diquark model. The spectra of the positive- and negative-parity states of , , and are obtained. The masses and interaction parameters of the effective theory are fixed partly from the lattice QCD data and also from fitting low-lying heavy baryon masses. We find that the negative parity excited states of (flavor ) are different from those of , because of the inverse hierarchy of the pseudoscalar diquark. On the other hand, and (flavor ) baryons have similar spectra. We compare our results of the heavy-quark--diquark model with experimental data as well as the quark model.

    Comments:
    19 pages, 10 figures
    Subjects:
    High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
    arXiv:
    2105.09087 [pdf]
    PRD(2021)·27 citations

Affiliations

first authorsco-authorsvia INSPIRE