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Related papers: Untwisting twisted NJL$_2$-kinks by a bare fermion…

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We use the effective chiral Lagrangian to analyze the phase diagram of two-flavor twisted mass lattice QCD as a function of the normal and twisted masses, generalizing previous work for the untwisted theory. We first determine the chiral…

High Energy Physics - Lattice · Physics 2009-11-10 Stephen R. Sharpe , Jackson M. S. Wu

The central two-pion exchange NN potential at large distances is studied in the framework of relativistic chiral symmetry and related directly to the nucleon scalar form factor, which describes the mass density of its pion cloud. This…

Nuclear Theory · Physics 2009-11-06 M. R. Robilotta

By considering baryons as clusters of three quarks, we extend the Nambu-Jona-Lasinio (NJL) model to describe baryonic matter, quark matter, and their transitions in a unified manner, where the Dirac sea and spontaneous chiral symmetry…

Nuclear Theory · Physics 2024-09-20 Cheng-Jun Xia

The Nielsen-Ninomiya theorem, dubbed `fermion-doubling', poses a problem for the naive discretization of a single (massless) Dirac cone on a two-dimensional surface. The inevitable appearance of an additional, unphysical fermionic mode can,…

Mesoscale and Nanoscale Physics · Physics 2023-06-21 Alexander Ziesen , Ion Cosma Fulga , Fabian Hassler

A new class of traversable wormholes was recently constructed which relies only on local bulk dynamics rather than an explicit coupling between distinct boundaries. Here we begin with a four-dimensional Weyl fermion field of any mass $m$…

High Energy Physics - Theory · Physics 2019-11-15 Donald Marolf , Sean McBride

We evaluate the dispersion relation for massless fermions, described by the Dirac equation, and for zero-spin bosons, described by the Klein-Gordon equation, moving in two dimensions and in the presence of a one-dimensional periodic…

Mesoscale and Nanoscale Physics · Physics 2015-03-17 M. Barbier , F. M. Peeters , P. Vasilopoulos , J. Milton Pereira

In this contribution, results from $N_f=2$ lattice QCD simulations at one lattice spacing using twisted mass fermions with a clover term at the physical pion mass are presented. The mass splitting between charged and neutral pions…

We study the lattice cutoff ($a$) and quark mass dependences of pion masses and decay constants in the $N_f = 2$ twisted mass QCD, using the Wilson chiral perturbation theory to the next leading order (NLO). In order to investigate the…

High Energy Physics - Lattice · Physics 2011-11-02 Satoru Ueda , Sinya Aoki

We present results on the spin and quark content of the nucleon using $N_f=2$ twisted mass clover-improved fermion simulations with a pion mass close to its physical value. We use recently developed methods to obtain accurate results for…

High Energy Physics - Lattice · Physics 2016-11-29 C. Alexandrou , M. Constantinou , K. Hadjiyiannakou , Ch. Kallidonis , G. Koutsou , K. Jansen , Ch. Wiese , A. Vaquero Avilés-Casco

We investigate how a dynamical mass of a fermion is affected by a topological mass of a gauge field in a Maxwell-Chern-Simons $QED_3$ coupled with a two-component fermion. The dynamical mass and also a parity condensate are estimated by…

High Energy Physics - Theory · Physics 2009-10-31 Toyoki Matsuyama , Hideko Nagahiro

We compare overlap fermions, which are chirally invariant, and Wilson twisted mass fermions in the approach to the chiral limit. Our quenched simulations reveal that with both formulations of lattice fermions pion masses of O(250 MeV) can…

In this proceeding contribution we report on the ongoing effort to simulate Wilson-type fermions in the so called epsilon regime of chiral perturbation theory. We present results for the chiral condensate and the pseudoscalar decay constant…

High Energy Physics - Lattice · Physics 2010-11-05 K. Jansen , A. Shindler

The NJL-jet model provides a sound framework for calculating the fragmentation func- tions in an effective chiral quark theory, where the momentum and isospin sum rules are satisfied without the introduction of ad hoc parameters [1].…

Nuclear Theory · Physics 2011-04-06 Hrayr H. Matevosyan , Anthony W. Thomas , Wolfgang Bentz

We determine the phase diagram and pion spectrum for Wilson and twisted-mass fermions in the presence of non-degeneracy between the up and down quark and discretization errors, using Wilson and twisted-mass chiral perturbation theory. We…

High Energy Physics - Lattice · Physics 2014-12-03 Derek P. Horkel , Stephen R. Sharpe

We determine the phase diagram and chiral condensate for lattice QCD with two flavors of twisted-mass fermions in the presence of nondegenerate up and down quarks, discretization errors and a nonzero value of $\Theta_{\rm QCD}$. Although…

High Energy Physics - Lattice · Physics 2015-11-25 Derek P. Horkel , Stephen R. Sharpe

The effective potential for the Wilson loop in the SU(2) gauge theory with N_f massive fundamental and N_a massive adjoint fermions on S^1 x M^4 is computed at the one-loop level, assuming periodic boundary conditions for the gauge field…

High Energy Physics - Phenomenology · Physics 2009-11-10 Muge Boz , Namik K. Pak

We study the properties of pions in twisted mass lattice QCD (with two degenerate flavors) using chiral perturbation theory (ChPT). We work to next-to-leading order (NLO) in a power counting scheme in which m_q ~ a \Lambda_QCD^2, with m_q…

High Energy Physics - Lattice · Physics 2009-11-10 Stephen R. Sharpe , Jackson M. S. Wu

The maximally twisted lattice QCD action of an $SU_f(2)$ doublet of mass degenerate Wilson quarks gives rise to a real positive fermion determinant and it is invariant under the product of standard parity times the change of sign of the…

High Energy Physics - Lattice · Physics 2009-11-10 R. Frezzotti , G. C. Rossi

We present a comprehensive tensor network study of staggered, Wilson, and twisted mass fermions in the Hamiltonian formulation, using the massive two-flavor Schwinger model as a benchmark. Particular emphasis is placed on twisted mass…

High Energy Physics - Lattice · Physics 2026-04-14 Tim Schwägerl , Karl Jansen , Stefan Kühn

A cluster algorithm is constructed and applied to study the chiral limit of the strongly coupled lattice Schwinger model involving staggered fermions. The algorithm is based on a novel loop representation of the model. Finite size scaling…

High Energy Physics - Lattice · Physics 2009-11-07 Shailesh Chandrasekharan