118678327
Entanglement temperature and entanglement entropy of excited states
A bstractWe derive a general relation between the ground state entanglement Hamiltonian and the physical stress tensor within the path integral formalism. For spherical entangling surfaces in a CFT, we reproduce the local ground state entanglement Hamiltonian derived by Casini, Huerta and Myers. The resulting reduced density matrix can be characterized by a spatially varying “entanglement temperature”. Using the entanglement Hamiltonian, we calculate the first order change in the entanglement entropy due to changes in conserved charges of the ground state, and find a local first law-like relation for the entanglement entropy. Our approach provides a field theory derivation and generalization of recent results obtained by holographic techniques. However, we note a discrepancy between our field theoretically derived results for the entanglement entropy of excited states with a non-uniform energy density and current holographic results in the literature. Finally, we give a CFT derivation of a set of constraint equations obeyed by the entanglement entropy of excited states in any dimension. Previously, these equations were derived in the context of holography.
119259871
Bosonization and the Berry connection in two-dimensional QED
The dynamical effects of topological charge in two-dimensional QED can be expressed in terms of a topological order parameter via a Berry phase construction. The Berry phase describes the electric charge polarization of the vacuum in a manner similar to the theory of polarization in topological insulators. The topological order parameter labels discrete vacua which differ by units of electric flux. Here the associated Berry connection is explicitly constructed from the Dirac Hamiltonian eigenstates by introducing a small attractive Thirring coupling, so that there is still a stable boson in the limit of zero EM coupling. The Berry connection arises from the analytic structure of the Bethe ansatz states in complex rapidity near the free fermion point.
9248539
Entanglement Hamiltonians for Chiral Fermions with Zero Modes.
In this Letter, we study the effect of topological zero modes on entanglement Hamiltonians and the entropy of free chiral fermions in (1+1)D. We show how Riemann-Hilbert solutions combined with finite rank perturbation theory allow us to obtain exact expressions for entanglement Hamiltonians. In the absence of the zero mode, the resulting entanglement Hamiltonians consist of local and bilocal terms. In the periodic sector, the presence of a zero mode leads to an additional nonlocal contribution to the entanglement Hamiltonian. We derive an exact expression for this term and for the resulting change in the entanglement entropy.
121009870
Muon-electron transitions in models of radiative lepton masses
In models where both the electron and muon acquire radiative masses, the same mechanism often allows μ-e transitions as well at a certain level. We discuss the phenomenological constraints on some recently proposed models of this type and show that they are incompatible with present experimental limits on μ→eγ, and in one case also μ→eee, without the fine tuning of parameters which these models are supposed to avoid.
121842859
TWO-BODY RADIATIVE GLUINO DECAYS
A gluino can decay into a color-singlet neutral fermion by radiating off a gluon. We study this process in a minimal supersymmetric extension of the standard model. A significant branching fraction is possible depending on how much overlaps with the Higgs fermion which couples to the t quark and the mass of the t quark itself.
115458701
The Asymmetric Left-Right Electroweak Gauge Model