Related papers: Overlap for 2D chiral U(1) models
We compute fermionic observables relevant to the study of chiral symmetry in quenched QCD using the Overlap-Dirac operator for a wide range of the fermion mass. We use analytical results to disentangle the contribution from exact zero modes…
We examine the vacuum overlap formula for the two-dimensional SU(2) Wess-Zumino term in lattice regularization. Perturbatively it reproduces the Wess-Zumino term correctly in the continuum limit and yields the IR fixed point in the beta…
Dynamical nature of the gauge degrees of freedom and its effect to fermion spectrum are studied at $\beta=\infty$ for two- and four-dimensional nonabelian chiral gauge theories in the vacuum overlap formalism. It is argued that the…
We study the dynamics and phase structure of Abelian gauge theories in $d=1+1$ dimensions. These include $U(1)$ gauge theory coupled to a scalar and a fermion, as well as the two-flavour Schwinger model with different charges. Both theories…
We investigate the possibility of coupling a chemical potential only to the physical chiral fermions on the lattice starting from the many body state description of overlap fermions. After developing the formalism for a chiral gauge theory,…
The Overlap-Dirac operator provides a lattice regularization of massless vector gauge theories with an exact chiral symmetry. Practical implementations of this operator and recent results in quenched QCD using this Overlap-Dirac operator…
We compute light and strange quark masses for quenched overlap fermions at two values of the gauge coupling. The renormalisation is done non-perturbatively. We test the predictions of quenched chiral perturbation theory for the quark mass…
We present some results pertaining to partially quenched formulations of the overlap/domain wall operator with the Thirring model in 2+1D. Auxiliary fields are generated with a Shamir domain wall approach and measurements of eigenvalues and…
Overlap fermions are a powerful tool for investigating the chiral and topological structure of the vacuum and the thermal states of QCD. We study various chiral and topological aspects of the finite temperature phase transition of N_f=2…
We show that the 3450 U(1) chiral fermion theory can appear as the low energy effective field theory of a 1+1D local lattice model, with an on-site U(1) symmetry and finite-range interactions. The on-site U(1) symmetry means that the U(1)…
We consider the fermion spectrum in the strong coupling vortex phase of a lattice fermion-scalar model with a global $U(1)_L\times U(1)_R$, in 2D, in the context of a recently proposed two-cutoff lattice formulation. The fermion doublers…
The topological charge in the $\U(N)$ vector-like reduced model can be defined by using the overlap Dirac operator. We obtain its large $N$ limit for a fermion in a general gauge-group representation under a certain restriction of gauge…
We examine the axial U(1) symmetry near and above the finite temperature phase transition in two-flavor QCD using lattice QCD simulations. Although the axial U(1) symmetry is always violated by quantization, (i.e.) the chiral anomaly, the…
Overlap formalism deals with the construction of chiral gauge theories on the lattice. These set of lectures provide a pedagogical introduction to the subject with emphasis on chiral anomalies and gauge field topology. Subtleties associated…
The chiral fermion model with local multifermion interactions proposed in Nucl. Phys. B486 (1997) 282 and Phys. Rev. D61 (2000) 054502 processes an exact SU_L(2) chiral gauge symmetry and SU_L(2) by U_R(1) chiral flavour symmetry on a…
We present simulation results for the 2-flavour Schwinger model with dynamical overlap fermions. In particular we apply the overlap hypercube operator at seven light fermion masses. In each case we collect sizable statistics in the…
In the continuum, the single flavor massless Schwinger model has an exact global axial $U(1)$ symmetry in the sector of perturbative gauge fields. This symmetry is explicitly broken by gauge fields with nonzero topological charge inducing a…
Recent lattice measurements of the topological susceptibility of SU(2) gauge theory using improved cooling and inverse-blocking are in disagreement. We use the overlap method, which probes the fermionic sector of the theory directly, to…
The CPT anomaly, which was first seen in perturbation theory for certain four-dimensional chiral gauge theories, is also present in the exact result for a class of two-dimensional chiral U(1) gauge theories on the torus. Specifically, the…
Lattice fermions have well-known difficulties with chiral symmetry. To evade them it is possible to couple continuum fermions to lattice gauge fields, by introducing an interpolation of the latter. Following this line of thinking, this…