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Related papers: Quark masses and strong CP violation

200 papers

A simple breaking of the subnuclear democracy among the quarks leads to a mixing between the second and the third family, in agreement with observation. Introducing the mixing between the first and the second family, one finds an…

High Energy Physics - Phenomenology · Physics 2007-05-23 Harald Fritzsch

In view of the observed strong hierarchy of quark masses, we discuss a new description of flavor mixing which is particularly suited for models of quark mass matrices based on flavor symmetries. The necessary and sufficient conditions for…

High Energy Physics - Phenomenology · Physics 2007-05-23 Harald Fritzsch

I give a brief overview of recent results from lattice QCD calculations which are relevant for the phenomenology of the Standard Model. I discuss, in particular, the lattice determination of light quark masses and the calculation of those…

High Energy Physics - Phenomenology · Physics 2009-10-31 Vittorio Lubicz

In view of the observed strong hierarchy of the quark and lepton masses and of the flavor mixing angles it is argued that the description of flavor mixing must take this into account. One particular interesting way to describe the flavor…

High Energy Physics - Phenomenology · Physics 2007-05-23 Harald Fritzsch

Baker, Ball and Zachariasen have developed an elegant formulation of the dual superconducting model of quantum chromodynamics (QCD), which allows one to use the field equations to eliminate the gluon and Higgs degrees of freedom and thus to…

High Energy Physics - Theory · Physics 2009-10-30 Lewis P. Fulcher

The conventional view is that a solution of the strong CP problem lies beyond QCD. A strong argument supporting this view is that the chiral expansion shows that observables depend on theta (unless a quark mass is zero); this eliminates the…

High Energy Physics - Phenomenology · Physics 2019-05-15 Thomas D. Cohen

The premise of an organizing quadratic hierarchy rule in lepton-quark flavor physics was used earlier for explanation of the hierarchy patterns of four generic pairs of flavor quantities 1) charged-lepton and 2) neutrino deviations from…

High Energy Physics - Phenomenology · Physics 2007-10-24 E. M. Lipmanov

We consider two-flavor asymmetric QCD combined with a low-energy effective model inspired by chiral perturbation theory and lattice data to investigate the effects of masses, isospin and baryon number on the pressure and the deconfinement…

High Energy Physics - Phenomenology · Physics 2009-03-23 L. F. Palhares , E. S. Fraga , C. Villavicencio

We have simulated QCD using 2+1 flavors of domain wall quarks on a $(2.74 {\rm fm})^3$ volume with an inverse lattice scale of $a^{-1} = 1.729(28)$ GeV. The up and down (light) quarks are degenerate in our calculations and we have used four…

Results from our recent investigations of quark number susceptibilities in both quenched and 2-flavour QCD are presented as a function of valence quark mass and temperature. A strong reduction (approx. 40%) is seen in the strange quark…

High Energy Physics - Phenomenology · Physics 2015-06-25 Rajiv V. Gavai

I review lattice QCD calculations of the strong coupling and quark masses.

High Energy Physics - Lattice · Physics 2015-06-16 Craig McNeile

N=1 SQCD with N_c colors and two types of light quarks: N_l flavors with smaller masses m_l and N_h=N_F-N_l flavors with larger masses m_h, N_c<N_F<3N_c, 0<m_l \leq m_h \ll \Lambda, is considered within the dynamical scenario in which…

High Energy Physics - Theory · Physics 2011-03-04 Victor L. Chernyak

The mass difference of $c$ and $u$ quarks is similar to the energy needed to excite gluonic degrees of freedom in strong QCD. This underpins the degeneracy of $D$ and a recently observed candidate hybrid excitation of the $\pi$ at$\sim…

High Energy Physics - Phenomenology · Physics 2011-02-01 Frank E. Close , Harry J. Lipkin

We discuss a possible solution to the strong CP problem which is based on spontaneous CP violation and discrete symmetries. At the same time we predict in a simple way the almost right-angled quark unitarity triangle angle ($\alpha \simeq…

High Energy Physics - Phenomenology · Physics 2015-06-09 Martin Spinrath

Recently, it was shown that modular symmetry may solve the strong CP problem without axions, by producing a vanishing QCD angle while generating a large quark CP violation phase. We extend this framework to finite modular groups,…

High Energy Physics - Phenomenology · Physics 2024-10-25 J. T. Penedo , S. T. Petcov

The concept of QCD sum rules is extended to bound states composed of particles with finite mass such as scalar quarks or strange quarks. It turns out that mass corrections become important in this context. The number of relevant corrections…

High Energy Physics - Phenomenology · Physics 2015-06-25 M. Meyer-Hermann , A. Schäfer , W. Greiner

If supersymmetry exists at low energies, it is necessary to understand why the squark spectrum exhibits sufficient degeneracy to suppress flavor changing neutral currents. In this note, we point out that gauged horizontal symmetries can…

High Energy Physics - Phenomenology · Physics 2010-11-01 M. Dine , A. Kagan , R. G. Leigh

Some time ago Dashen pointed out that spontaneous CP violation can occur in the strong interactions. I show how a simple effective Lagrangian exposes the remarkably large domain of quark mass parameters for which this occurs. I close with…

High Energy Physics - Lattice · Physics 2009-11-10 Michael Creutz

Two twisted doublets, one containing the up and down quarks and the other containing the strange quark with an SU(2)-flavor partner, are used for studies in the meson sector. The relevant chiral perturbation theory is presented, and…

High Energy Physics - Lattice · Physics 2011-02-01 Abdou M. Abdel-Rehim , Randy Lewis , R. M. Woloshyn , Jackson M. S. Wu

QCD lattice simulations with 2+1 flavours typically start at rather large up-down and strange quark masses and extrapolate first the strange quark mass to its physical value and then the up-down quark mass. An alternative method of tuning…