English
Related papers

Related papers: Flavor Dependence of the S-parameter

200 papers

An SU(2) gauge theory with two fermions transforming under the adjoint representation of the gauge group may appear conformal or almost conformal in the infrared. We use lattice simulations to study the spectrum of this theory and present…

High Energy Physics - Lattice · Physics 2009-05-12 Ari J. Hietanen , Jarno Rantaharju , Kari Rummukainen , Kimmo Tuominen

Incorporated with twisted boundary condition, Polyakov loop correlators can give a definition of the renormalized coupling. We employ this scheme for the step scaling method (with step size s = 2) in the search of conformal fixed point of…

We investigate the superconformal index of a three-dimensional $SU(2)$ ${\mathcal N}=2$ supersymmetric QCD with $N_f=4$ flavors. This theory confines with the breaking of a global symmetry. We obtain the index of this theory by integrating…

High Energy Physics - Theory · Physics 2023-03-02 Ilmar Gahramanov

A grand unified $SU(5)$ theory is constructed with a hierarchical breaking of a $U(2)$ flavor symmetry. The small parameters of the squark and slepton mass matrices, necessary to solve the supersymmetric flavor-changing problem, and the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Riccardo Barbieri , Lawrence Hall

Finite size scaling is a powerful tool to study the critical properties of systems governed by one relevant operator, assuming all irrelevant operators have scaling dimensions much smaller then zero. This condition is likely not satisfied…

High Energy Physics - Lattice · Physics 2022-09-21 Anna Hasenfratz , Anqi Cheng , Gregory Petropoulos , David Schaich

The observed hierarchy of fermion masses and mixings may be generated by renormalization group flow if the Standard Model is coupled to a near-conformal sector at high energies. If the conformal sector is supersymmetric, these effects are…

High Energy Physics - Phenomenology · Physics 2010-07-14 Nathaniel Craig

We study the alignment of the vacuum in gauge theories with $N_f$ Dirac fermions transforming according to a complex representation of the gauge group. The alignment of the vacuum is produced by adding a small mass perturbation to the…

High Energy Physics - Phenomenology · Physics 2014-06-06 Thomas A. Ryttov

We have measured the running coupling constant of SU(3) gauge theory coupled to Nf=2 flavors of symmetric representation fermions, using the Schrodinger functional scheme. Our lattice action is defined with hypercubic smeared links which,…

High Energy Physics - Lattice · Physics 2014-11-21 Thomas DeGrand , Yigal Shamir , Benjamin Svetitsky

We study the transition between spontaneous chiral symmetry breaking and conformal behavior in the SU(3) theory with multiple fermion flavors. Instead of the traditional approach of changing the number of flavors, we keep the number of…

High Energy Physics - Lattice · Physics 2014-11-13 Rich Brower , Anna Hasenfratz , Claudio Rebbi , Evan Weinberg , Oliver Witzel

Based upon flavor SU(3) symmetry, we perform global fits to charmless B decays into one pseudoscalar meson and one vector meson in the final states. We consider different symmetry breaking schemes and find that the one implied by na{\"i}ve…

High Energy Physics - Phenomenology · Physics 2009-03-27 Cheng-Wei Chiang , Yu-Feng Zhou

We propose a method for determining the flavor charge lattice of the continuous flavor symmetry of rank-1 4d N = 2 superconformal field theories (SCFTs) and IR free gauge theories from topological invariants of the special K\"ahler…

High Energy Physics - Theory · Physics 2019-02-20 Philip C. Argyres , Matteo Lotito

In Part 1 of this series of papers, we described a general method for determining the flavor symmetry of any 5d SCFT which can be constructed by integrating out BPS particles from some 6d SCFT compactified on a circle. In this part, we…

High Energy Physics - Theory · Physics 2021-05-12 Lakshya Bhardwaj

When the flavour content of QCD is increased sufficiently, the theory develops a non-trivial infra red fixed point. Thus, for a number of flavours above a certain critical value, but not yet so high that asymptotic freedom is lost, QCD…

High Energy Physics - Lattice · Physics 2010-01-21 Albert Deuzeman , Maria Paola Lombardo , Elisabetta Pallante

The scale-dependent renormalized coupling of SU(3) gauge theory coupled to Nf = 2 flavors of massless Dirac flavors in the sextet representation is presented in the range 0 < g^2 < 6.5. This range includes the location where the…

High Energy Physics - Lattice · Physics 2015-11-17 Zoltan Fodor , Kieran Holland , Julius Kuti , Santanu Mondal , Daniel Nogradi , Chik Him Wong

We investigate the chiral phase transition in SU(N) gauge theories as the number of quark flavors, $N_f$, is varied. We argue that the transition takes place at a large enough value of $N_f$ so that it is governed by the infrared fixed…

High Energy Physics - Phenomenology · Physics 2014-11-17 Thomas Appelquist , Anuradha Ratnaweera , John Terning , L. C. R. Wijewardhana

Nonperturbative lattice field theory simulations provide a systematic framework to investigate properties of conformal systems at strong couplings. These simulations can be performed using different lattice discretizations. Here we present…

High Energy Physics - Lattice · Physics 2019-09-13 A. Hasenfratz , C. Rebbi , O. Witzel

Supersymmetric gauge models with local horizontal symmetries are known to generate large flavor changing neutral current effects induced by supersymmetry breaking D-terms. We show how the presence of a U(1) gauge symmetry solves this…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. S. Babu , R. N. Mohapatra

Two-body charmed meson decays $D\to VP$ are studied within the framework of the diagrammatic approach. Under flavor SU(3) symmetry, all the flavor amplitude sizes and their associated strong phases are extracted by performing a $\chi^2$…

High Energy Physics - Phenomenology · Physics 2016-06-15 Hai-Yang Cheng , Cheng-Wei Chiang , An-Li Kuo

We provide an extended lattice study of the SU(2) gauge theory coupled to one Dirac fermion flavour ($N_{\mathrm{f}} =1$) transforming in the adjoint representation as the continuum limit is approached. This investigation is supplemented by…

High Energy Physics - Lattice · Physics 2026-04-13 Andreas Athenodorou , Ed Bennett , Georg Bergner , Pietro Butti , Julian Lenz , Biagio Lucini

Recently the Lattice Strong Dynamics Collaboration reported a reduction of the electroweak S parameter for SU(3) gauge theory with Nf=6 fermions in the fundamental representation, compared to scaled-up QCD (arXiv:1009.5967). Here I provide…

High Energy Physics - Lattice · Physics 2022-09-21 David Schaich