English
Related papers

Related papers: S parameter and parity doubling below the conforma…

200 papers

First results from simulations of improved actions for both gauge fields and staggered fermion fields in three dimensional QCD are presented. This work provides insight into some issues of relevance to lattice theories in four dimensions.…

High Energy Physics - Lattice · Physics 2011-07-19 Howard D. Trottier

We consider the extended electroweak gauge group SU(2)_1 \times SU(2)_2 \times U(1)_Y where the first and second families of fermions couple to SU(2)_1 while the third family couples to SU(2)_2. Bounds based an precision electroweak…

High Energy Physics - Phenomenology · Physics 2007-05-23 David J. Muller , Satya Nandi

We consider the two-dimensional N=(2,2) Wess-Zumino model with a cubic superpotential at weak and intermediate couplings. Refined algorithms allow for the extraction of reliable masses in a region where perturbation theory no longer…

High Energy Physics - Lattice · Physics 2008-11-26 Tobias Kaestner , Georg Bergner , Sebastian Uhlmann , Andreas Wipf , Christian Wozar

Using lattice simulations, we study the extent of the conformal window for an $\text{SU}(3)$ gauge theory with $N_f$ Dirac fermions in the fundamental representation. We present evidence that the infrared behavior is conformal for $12 \leq…

High Energy Physics - Phenomenology · Physics 2009-12-15 Thomas Appelquist , George T. Fleming , Ethan T. Neil

I investigate an SU(3) gauge model with 12 fundamental fermions. The physically interesting region of this strongly coupled system can be influenced by an ultraviolet fixed point due to lattice artifacts. I suggest to use a gauge action…

High Energy Physics - Lattice · Physics 2013-05-30 Anna Hasenfratz

We show that, unlike mass matrices, the fermionic gauge currents of the Standard Model exhibit, at the quantum level, remarkable SU(2)_f flavor properties at the observed values of the mixing angles. They accommodate all measured mixing for…

High Energy Physics - Phenomenology · Physics 2012-03-28 Bruno Machet

We consider a five dimensional SU(2) gauge theory with fermions in the bulk and with additional SU(2) and U(1) kinetic terms on the branes. The electroweak breaking is obtained by boundary conditions. After deconstruction, fermions in the…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. Bechi , R. Casalbuoni , S. De Curtis , D. Dominici

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…

High Energy Physics - Lattice · Physics 2010-03-19 P. Hernandez , Ph. Boucaud

Baryonic correlation functions provide an ideal tool to study parity doubling and chiral symmetry using lattice simulations. We present a study using $2+1$ flavors of anisotropic Wilson clover fermions on the FASTSUM ensembles and find…

High Energy Physics - Lattice · Physics 2016-07-19 Gert Aarts , Chris Allton , Davide De Boni , Simon Hands , Benjamin Jäger , Chrisanthi Praki , Jon-Ivar Skullerud

We present our preliminary study of the SU(2) gauge theory with 8 flavors of fermions in fundamental representation. This theory could be a candidate of the gauge theory with conformal fixed point. By using Wilson/Polyakov loop in a finite…

We use lattice simulations to study the single-site version of SU(N) lattice gauge theory with two flavors of Wilson-Dirac fermions in the adjoint representation, a theory whose large volume correspondent is expected to be conformal or…

High Energy Physics - Lattice · Physics 2013-05-30 Barak Bringoltz , Mateusz Koren , Stephen R. Sharpe

We analyze the dynamics of an $SU_L(2)\otimes U_R(1)$ chiral gauge theory on a lattice with a large multifermion coupling $1\ll g_2 < \infty$. It is shown that no spontaneous symmetry breaking occurs; the ``spectator'' fermion $\psi_R(x)$…

High Energy Physics - Lattice · Physics 2008-02-03 She-Sheng Xue

We consider an extended gauge group for the electroweak interaction: SU(2)_1 \times SU(2)_2 \times U(1)_Y where the first and second generations of fermions couple to SU(2)_1 while the third generation couples to SU(2)_2. Bounds based on…

High Energy Physics - Phenomenology · Physics 2011-01-25 David Muller , Satya Nandi

We summarize our recent work on gauge theories with two flavors of fermions in the two-index symmetric representation: SU(2) gauge theory with adjoint fermions, SU(3) with sextets, and SU(4) with ten-dimensional-representation fermions. All…

High Energy Physics - Lattice · Physics 2011-11-02 Thomas DeGrand , Yigal Shamir , Benjamin Svetitsky

We elaborate on a recently suggested effective Lagrangian for charged-current and neutral-current electroweak interactions which in comparison with the standard electroweak theory contains three free parameters $\Delta x, \Delta y$,…

High Energy Physics - Phenomenology · Physics 2009-10-28 S. Dittmaier , D. Schildknecht , K. Kolodziej , M. Kuroda

The most important hint of physics beyond the Standard Model (SM) from the 1995 precision electroweak data is that the most precisely measured quantities, the total, leptonic and hadronic decay widths of the $Z$ and the effective weak…

High Energy Physics - Phenomenology · Physics 2010-11-23 Kaoru Hagiwara

Based on a nonabelian generalization of electric-magnetic duality, the Dualized Standard Model (DSM) suggests a natural explanation for exactly 3 generations of fermions as the `dual colour' $\widetilde{SU}(3)$ symmetry broken in a…

High Energy Physics - Phenomenology · Physics 2007-05-23 HM Chan , ST Tsou

In the recently proposed dark left-right gauge model of particle interactions, the left-handed fermion doublet $(\nu,e)_L$ is connected to its right-handed counterpart $(n,e)_R$ through a scalar bidoublet, but $\nu_L$ couples to $n_R$ only…

High Energy Physics - Phenomenology · Physics 2010-04-22 Alfredo Aranda , J. Lorenzo Díaz-Cruz , Jaime Hernández-Sánchez , Ernest Ma

We extend the Standard Model (SM) by adding a pair of fermionic SU(2)-doublets with opposite hypercharge and a fermionic SU(2)-triplet with zero hypercharge. We impose a discrete Z_2-symmetry that distinguishes the SM fermions from the new…

High Energy Physics - Phenomenology · Physics 2015-06-24 Athanasios Dedes , Dimitrios Karamitros

We investigate the Sudakov double logarithmic corrections to the form factor of fermion in the SU(2)XU(1) electroweak theory. We adopt the familiar Feynman gauge and present explicit calculations at the two loop level. We show that the…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Hori , H. Kawamura , J. Kodaira