Baryons under Strong Magnetic Fields or in Theories with Space-dependent $\theta$-term

Abstract

Baryonic states are sufficiently complex to reveal physics that is hidden in the mesonic bound states. Using gauge/gravity correspondence we study analytically and numerically baryons in theories with space-dependent $\theta$-term, or theories under strong magnetic fields. Such holographic studies on baryons are accommodated in a generic analytic framework we develop for anisotropic theories, where their qualitative features are common irrespective of the source that triggers the anisotropy. We find that the distribution of the quarks forming the state, depends on the angle between the baryon and the anisotropic direction. Its shape is increasingly elliptic with respect to the strength of the field sourcing the anisotropy, counterbalancing the broken rotational invariance on the gluonic degrees of freedom. Strikingly, the baryons dissociate in stages with a process that depends on the proximity of the quarks to the anisotropic direction, where certain quark pairs abandon the bound state first, followed by the closest pairs to them as the temperature increases. This observation may also serve as a way to identify the nature of certain exotic states. Finally, we investigate holographic baryons with decreased number of quarks and explain why in theories under consideration the presence of anisotropy does not modify the universal stability condition in contrast to the usual trend.

37 pages, 12 figures; v2 minor improvements, references added

References in corpus (20)

• Heavy quarkonium: progress, puzzles, and opportunities
• Hadronic molecules
• Multiquark Resonances
• Non-Standard Heavy Mesons and Baryons, an Experimental Review
• Exotics: Heavy Pentaquarks and Tetraquarks
• Quantum field theory in a magnetic field: From quantum chromodynamics to graphene and Dirac semimetals
• Observation of a resonance-like structure in the pi^+- psi' mass distribution in exclusive B-->K pi^+- psi' decays
• On String Theory Duals of Lifshitz-like Fixed Points
• Strongly-coupled anisotropic gauge theories and holography
• A Strongly Coupled Anisotropic Fluid From Dilaton Driven Holography
• Langevin diffusion of heavy quarks in non-conformal holographic backgrounds
• Holographic estimate of heavy quark diffusion in a magnetic field
• Quarkonium dissociation by anisotropy
• Strong decays of exotic and non-exotic heavy baryons in the chiral quark-soliton model
• Velocity Dependence of Baryon Screening in a Hot Strongly Coupled Plasma
• From Decay to Complete Breaking: Pulling the Strings in SU(2) Yang-Mills Theory
• The Nc dependencies of baryon masses: Analysis with Lattice QCD and Effective Theory
• Stability issues with baryons in AdS/CFT
• Thermodynamics of anisotropic branes
• Supersymmetric Gauge Theory with Space-time Dependent Couplings

Cited by in corpus (6)

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• Quasinormal modes for quarkonium in a plasma with magnetic fields
• Confining and chiral properties of QCD in extremely strong magnetic fields
• Holographic QCD and magnetic fields
• Holographic Non-local Rotating Observables and their Renormalization
• Generation of gravitating solutions with Baryonic charge from Einstein-Scalar-Maxwell seeds