Imaginary magnetic fields induce exceptional points in neutral meson mass spectra computed via hadronic effective Lagrangian and constituent quark models, separating real and complex eigenvalue regimes.
Neutron electric polarizability from unquenched lattice QCD using the background field ap- proach
2 Pith papers cite this work. Polarity classification is still indexing.
2
Pith papers citing it
abstract
A calculational scheme for obtaining the electric polarizability of the neutron in lattice QCD with dynamical quarks is developed, using the background field approach. The scheme differs substantially from methods previously used in the quenched approximation, the physical reason being that the QCD ensemble is no longer independent of the external electromagnetic field in the dynamical quark case. One is led to compute (certain integrals over) four-point functions. Particular emphasis is also placed on the physical role of constant external gauge fields on a finite lattice; the presence of these fields complicates the extraction of polarizabilities, since it gives rise to an additional shift of the neutron mass unrelated to polarizability effects. The method is tested on a SU(3) flavor-symmetric ensemble furnished by the MILC Collaboration, corresponding to a pion mass of m_pi = 759 MeV. Disconnected diagrams are evaluated using stochastic estimation. A small negative electric polarizability of alpha =(-2.0 +/- 0.9) 10^(-4) fm^3 is found for the neutron at this rather large pion mass; this result does not seem implausible in view of the qualitative behavior of alpha as a function of m_pi suggested by Chiral Effective Theory.
citation-role summary
background 1
citation-polarity summary
years
2026 2verdicts
UNVERDICTED 2roles
background 1polarities
background 1representative citing papers
Lattice QCD on quenched 24^3 x 48 lattices yields charged kaon electric polarizability α_E = (0.988 ± 0.534) × 10^{-4} fm³ and charge radius squared 0.3303 ± 0.0028 fm² after physical pion-mass extrapolation.
citing papers explorer
-
Hadronic exceptional points
Imaginary magnetic fields induce exceptional points in neutral meson mass spectra computed via hadronic effective Lagrangian and constituent quark models, separating real and complex eigenvalue regimes.
-
Charged kaon electric polarizability from four-point functions in lattice QCD
Lattice QCD on quenched 24^3 x 48 lattices yields charged kaon electric polarizability α_E = (0.988 ± 0.534) × 10^{-4} fm³ and charge radius squared 0.3303 ± 0.0028 fm² after physical pion-mass extrapolation.