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Related papers: Reaching the chiral limit in many flavor systems

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We investigate chiral and conformal properties of the lattice QCD with eight flavors (Nf=8) through meson spectrum using the Highly Improved Staggered Quark (HISQ) action. We also compare our results with those of Nf=12 and Nf=4 which we…

In this work we present the results of a numerical investigation of SU(2) gauge theory with N_f = 3/2 flavours of fermions, corresponding to 3 Majorana fermions, which transform in the adjoint representation of the gauge group. At two…

High Energy Physics - Lattice · Physics 2018-03-14 Georg Bergner , Pietro Giudice , Istvan Montvay , Gernot Münster , Stefano Piemonte , Philipp Scior

The Thirring model is a four fermion theory with vector interaction. We study it in three dimensions, where it is closely related to QED and other models used to describe properties of graphene. In addition it is a good toy model to study…

High Energy Physics - Lattice · Physics 2015-11-03 Daniel Schmidt , Björn Wellegehausen , Andreas Wipf

We present Monte Carlo simulation results for the three dimensional Thirring model on moderate sized lattices using a hybrid molecular dynamics algorithm which permits an odd or non-integer number Nf of fermion flavors. We find a continuous…

High Energy Physics - Lattice · Physics 2009-10-31 Simon Hands , Biagio Lucini

We study infrared conformality of the twelve-flavor QCD on the lattice. Utilizing the highly improved staggered quarks (HISQ) type action which is useful to study the continuum physics, we analyze the lattice data of the mass and the decay…

New tests are applied to two $\beta$-functions of the much-discussed BSM model with ten massless fermion flavors in the fundamental representation of the SU(3) color gauge group. The renormalization scheme of the two $\beta$-functions is…

High Energy Physics - Lattice · Physics 2022-03-31 Zoltán Fodor , Kieran Holland , Julius Kuti , Chik Him Wong

We re-analyze data from available finite-temperature QCD simulations near the chiral transition, with the help of Chiral Random Matrix Theory (chRMT). Statistical properties of the lowest-lying eigenvalues of the staggered Dirac operator…

High Energy Physics - Lattice · Physics 2009-10-31 F. Farchioni , Ph. de Forcrand , I. Hip , C. B. Lang , K. Splittorff

We present an update of our ongoing study of the SU(2) gauge theory with one flavor of Dirac fermion in the adjoint representation. Compared to our previous results we now have data at larger lattice volumes, smaller values of the fermion…

High Energy Physics - Lattice · Physics 2023-01-05 Ed Bennett , Andreas Athenodorou , Georg Bergner , Pietro Butti , Biagio Lucini

We construct a prototype BSM model based on the SU(3) color gauge group and a combination of 4 light (massless) and 8 heavy flavors. In the infrared, the SU(4) flavor chiral symmetry is spontaneously broken, while in the ultraviolet this…

High Energy Physics - Lattice · Physics 2016-11-23 Anna Hasenfratz , Claudio Rebbi , Oliver Witzel

We review our attempt at understanding the phase structure of lattice QCD with the Wilson fermion formulation at finite temperature, based on a spontaneous breakdown of parity-flavor symmetry. Numerical results demonstrating explicitly the…

High Energy Physics - Lattice · Physics 2009-10-30 S. Aoki

Mass-split composite Higgs models naturally accommodate the experimental observation of a light 125 GeV Higgs boson and predict a large scale separation to other heavier resonances. We explore the SU(3) gauge system with four light…

High Energy Physics - Phenomenology · Physics 2020-11-11 Oliver Witzel , Anna Hasenfratz , Curtis T. Peterson

We analyze newly expanded and refined data from lattice studies of an SU(3) gauge theory with eight Dirac fermions in the fundamental representation. We focus on the light composite states emerging from these studies, consisting of a set of…

The slowly evolving gauge coupling of gauge-fermion systems near the conformal window makes numerical investigations of these models challenging. We consider finite size scaling and show that this often used technique leads to inconsistent…

High Energy Physics - Lattice · Physics 2014-07-30 Anqi Cheng , Anna Hasenfratz , Yuzhi Liu , Gregory Petropoulos , David Schaich

We report the calculation of the flavor-singlet scalar in the SU(3) gauge theory with the degenerate twelve fermions in the fundamental representation using a HISQ-type action at a fixed $\beta$. In order to reduce the large statistical…

The QCD phase transition is studied on $16^3$ and $32^3 \times 4$ lattices both with and without quark loops. We introduce a new zero-flavor or quenched species of quark $\zeta$ and study the resulting chiral condensate, $\azbz$ as a…

High Energy Physics - Lattice · Physics 2009-10-28 Shailesh Chandrasekharan , Norman Christ

The magnitude of the $U_A(1)$ symmetry breaking is expected to affect the nature of $N_f=2$ QCD chiral phase transition. The explicit breaking of chiral symmetry due to realistic light quark mass is small, so it is important to use chiral…

High Energy Physics - Lattice · Physics 2015-10-15 Sayantan Sharma , Viktor Dick , Frithjof Karsch , Edwin Laermann , Swagato Mukherjee

Fermionic theories with a vanishing chiral condensate (in the chiral limit) have recently attracted considerable interest; in particular variants of multi-flavour QCD are candidates for this behaviour. Here we consider the 2-flavour…

High Energy Physics - Lattice · Physics 2020-07-14 Wolfgang Bietenholz , Ivan Hip , David Landa-Marbán

Despite intense experimental and theoretical research, the QCD phase diagram at finite baryon density remains to a large extent unexplored. From the theoretical side, the obvious non-perturbative approach is lattice QCD simulations, which…

We present a lattice study of the phase transitions at zero and nonzero temperature for the $SU(3)$ gauge theory with a varying number of flavours $N_f$ in the fundamental representation of the gauge group. We show that all results are…

High Energy Physics - Theory · Physics 2016-09-20 Tiago Nunes da Silva , Elisabetta Pallante , Lasse Robroek

We study the discrete beta function of SU(3) gauge theory with Nf=12 massless fermions in the fundamental representation. Using an nHYP-smeared staggered lattice action and an improved gradient flow running coupling $\tilde g_c^2(L)$ we…

High Energy Physics - Lattice · Physics 2018-02-28 Anna Hasenfratz , David Schaich