相关论文: Pseudoscalar Vertex and Quark Masses
We investigate a perturbative extension of the Standard Model featuring elementary pseudo-Goldstone Higgs and dark matter particles. These are two of the five Goldstone bosons parametrising the SU(4)/Sp(4) coset space. They acquire masses,…
We consider two SUSY-breaking hidden sectors which decouple when their respective couplings to the visible particles are switched off. In such a scenario one expects to find two light fermions: the Goldstino and the pseudo-Goldstino. While…
We discuss the sensitivity of nucleon properties (mass, magnetic moments and electromagnetic form factors) on the variation of the pseudoscalar meson masses in the context of the perturbative chiral quark model. The obtained results are…
Spectra of pions, which are known as the pseudo-Goldstone bosons of spontaneous chiral symmetry breaking, as well as their relationship with chiral phase transition and pion superfluidity phase transition, have been investigated in the…
We evaluate masses of bottom and charmed baryons using several non-relativistic quark potentials which parameters have been adjusted to the meson spectra. Heavy Quark Symmetry leads to important simplifications of the three body problem,…
There can arise ubiquitous ultra-light scalar fields in the Universe, such as the pseudo-Goldstone bosons from the spontaneous breaking of an approximate symmetry, which can make a partial contribution to the dark matter and affect the…
We perform hybrid Monte Carlo (HMC) simulatons of two flavors QCD with the optimal domain-wall fermion (ODWF) on the 16^3 x 32 lattice (with lattice spacing a ~ 0.1 fm), for eight sea-quark masses corresponding to pion masses in the range…
The mass spectrum of heavy pseudoscalar mesons, described as quark-antiquark bound systems, is considered within the Bethe-Salpeter formalism with momentum-dependent masses of the constituents. This dependence is found by solving the…
Heavy--light mesons are described in an effective quark theory with a two--body vector--type interaction. The bilocal interaction is taken to be instantaneous in the rest frame of the bound state, but formulated covariantly through the use…
We present a $SU(3)_F$ meson mass formula from random phase approximation (RPA). Both the mesons of ground-state pseudoscalar octet and the ground-state vector octet are described quite well in this mass formula. We also estimate the…
We show that a Z' with suppressed couplings to the electron compared to the Z-boson, with couplings to the b-quark, and with a mass close to the mass of the Z-boson, provides an excellent fit to forward-backward asymmetry of the b-quark and…
The mass splittings of the pseudoscalar and vector D and B light-heavy quark systems have been calculated using the method of QCD sum rules. Electromagnetic, quark mass, and nonperturbative QCD effects are all included. The results are in…
The strong coupling constant of doubly heavy baryons with light pseudoscalar mesons $ \pi $ and $ K $ are computed within the light cone sum rules. We take into account two-particle and three-particle distribution amplitudes of the said…
How the bulk of the Universe's visible mass emerges and how it is manifest in the existence and properties of hadrons are profound questions that probe into the heart of strongly interacting matter. Paradoxically, the lightest pseudoscalar…
We extend our previous formulation of low-energy QCD in terms of an effective lagrangian containing operators of dimensionality $d\le 6$ constructed with pseudoscalars and quark fields, describing physics below the scale of chiral symmetry…
The standard-model can be equivalently represented with its fields in a spin-extended basis, departing from fermion degrees of freedom. The common Higgs operator connects the electroweak and Yukawa sectors, restricting the top and bottom…
We consider chiral perturbation theory in a finite volume and in a mixed regime of quark masses. We take N_l light quarks near the chiral limit, in the so-called epsilon-regime, while the remaining N_h quarks are heavier and in the standard…
We consider order $\alpha_s$ corrections to the squared masses of the pseudo-Goldstone excitations about the ground state of dense quark matter. We show that these contributions tend to destabilize the vacuum, leading to a surprisingly…
Heavy baryon chiral perturbation theory is extended to include the effects of quenching. In this framework the leading nonanalytic dependence of the heavy baryon masses on the light quark masses is studied. The size of quenching effects is…
The PDG Tables list more scalar mesons than can fit into one quark model nonet: indeed, even more than can belong to two multiplets. Consequently, some of these must be states beyond the quark model. So which of these is ${\bar q}q$ or…