Emergent chirality and superfluidity of parity-doubled baryons in neutron stars

Abstract

We propose novel superfluids induced by the parity-doubled baryons. The parity-doubled baryons, i.e., a nucleon $N(940)$ with spin-parity $J^P=1/2^{+}$ and an excited nucleon $N^{\ast }(1535)$ with $J^P=1/2^{-}$ in vacuum, become degenerate at sufficiently high density where the chiral symmetry is restored. In this study, we extend the conventional $\mathrm{U}(1)$ chiral symmetry to the higher dimensional symmetries, dubbed emergent chiral symmetries, including the naive and mirror assignments as their subgroups. Starting with the Lagrangian up to four-point interactions among the neutron $n$ and its chiral partner $n^{\ast }$, neutral components in $N$ and $N^{\ast }$, in pure neutron matter, we investigate the properties of the ground state with a pairing gap generated by the $n$ and $n^{\ast }$ in the mean-field approximation. We find vector-type condensates that induce the dynamical breaking of a new class of internal symmetries, emergent chiral symmetries, as well as the baryon number and the rotational symmetries of the real space, indicating the appearance of massless Nambu-Goldstone bosons consisting of six quarks: emergent pions, superfluid phonons, and magnons, respectively. We also study the fermionic excitation modes at low-energy scales, and show that they exhibit a spatial anisotropy of the propagation at the Dirac cone in momentum space. Some phenomenological implications are advocated, shedding new light on the properties of neutron stars.

23 pages, 5 figures, 4 tables

References in corpus (31)

• Rapid Cooling of the Neutron Star in Cassiopeia A Triggered by Neutron Superfluidity in Dense Matter
• Counting rule for Nambu-Goldstone modes in nonrelativistic systems
• Strongly interacting matter exhibits deconfined behavior in massive neutron stars
• Superfluidity and Superconductivity in Neutron Stars
• Nucleons and parity doubling across the deconfinement transition
• Relativistic hybrid stars in light of the NICER PSR J0740+6620 radius measurement
• Quark-hadron crossover equations of state for neutron stars: constraining the chiral invariant mass in a parity doublet model
• Counting rule of Nambu-Goldstone modes for internal and spacetime symmetries: Bogoliubov theory approach
• SU(4) symmetry of the dynamical QCD string and genesis of hadron spectra
• Confirming the existence of twin stars in a NICER way
• Chiral spin symmetry and the QCD phase diagram
• Toward a unified equation of state for multi-messenger astronomy
• Chiral symmetry restoration and the $\Delta$ matter formation in neutron stars
• Collective modes of the order parameter in a triplet superfluid neutron liquid
• Topology and symmetry of surface Majorana arcs in cyclic superconductors
• Reconciling multi-messenger constraints with chiral symmetry restoration
• Stochastic processes for pulsar timing noise: fluctuations in the internal and external torques
• Zero sound in triplet-correlated superfluid neutron matter
• Insights into the physics of neutron star interiors from pulsar glitches
• Neutrino emissivity of anisotropic neutron superfluids
• Chiral spin symmetry and hot/dense QCD
• Fluctuations and correlations of baryonic chiral partners
• New eigen-mode of spin oscillations in the triplet superfluid condensate in neutron stars
• Non-Abelian Half-Quantum Vortices in ${}^3{P}_2$ Topological Superfluids
• Non-Abelian Anyons and Non-Abelian Vortices in Topological Superconductors
• Coexistence phase of ${}^1{S}_0$ and ${}^3{P}_2$ superfluids in neutron stars
• Vortex lattice in rotating neutron spin-triplet superfluid
• Spin-polarized phases of ${}^3{P}_2$ superfluids in neutron stars
• Core structures of vortices in Ginzburg-Landau theory for neutron ${}^3{P}_2$ superfluids
• Proximity effects of vortices in neutron ${}^3{P}_2$ superfluids in neutron stars: Vortex core transitions and covalent bonding of vortex molecules
• Gross-Neveu model with O(2)${}_L\times$O(2)${}_R$ chiral symmetry: Duality with Zakharov-Mikhailov model and large $N$ solution

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