Related papers: An extended model for nonet pseudo-scalar meson fr…
We apply a recently proposed mechanism -- in which an SU(3) symmetry predicts the weak mixing angle -- to construct realistic theories with composite quarks and leptons at a TeV. Although the models are strongly coupled, they are reliably…
We calculate quark and lepton masses and quark mixing angles in the framework of a supersymmetric SU(4)$\otimes$SU(2)$_L\otimes$SU(2)$_R$ model where the gauge group is broken at 10$^{16}$ GeV. The model predicts third family top-bottom-tau…
It has been realized for a long time that knowing the \eta and \eta' wave functions in terms of quark and gluon components probes our understanding of non-perturbative QCD dynamics. Great effort has been given to this challenge -- yet no…
Inclusive cross-sections for gluon jet production are studied numerically in the perturbative QCD pomeron model for central collisions of identical nuclei at high energies. Two forms for the inclusive cross-sections, with and without…
The perturbative QCD fragmentation functions for a heavy quark to fragment into heavy-light mesons are studied in the heavy-quark limit. The fragmentation functions for S-wave pseudoscalar and vector mesons are calculated to next-to-leading…
Using a simple quark-diquark model, we extract a set of unpolarized and polarized fragmentation functions for the $\Lambda$ based on the available unpolarized $\Lambda$ production data in $e^+ e ^- $ annihilation. It is found that there is…
The nonet symmetry scheme seems to describe rather well the masses and $\eta-\eta^{\prime}$ mixing angle of the ground state pseudo-scalar mesons and is thus expected to be also a good approximation for the matrix elements of the…
We evaluate the pseudoscalar-meson octet-baryon coupling constants and the corresponding axial charges in eight channels ($\pi N\N$, $\pi\Sigma\Sigma$, $\pi\Lambda\Sigma$, $K\Lambda N$, $K \Sigma N $, $\pi\Xi\Xi$, $K\Lambda\Xi$ and…
In this paper, we investigate three symmetry breaking effects in strong and radiative decays of strange heavy mesons. We study 1/m_Q corrections within the heavy quark effect theory, as well as SU(3) and SU(2) symmetry breakings induced by…
Quark and gluon parton dihadron fragmentation functions and their evolution are studied in the process of e+e- annihilation. We provide definitions of such dihadron fragmentation functions in terms of parton matrix elements and derive the…
We present a supersymmetric SU(5) GUT model with a discrete non-Abelian flavor symmetry that is broken by Wilson lines. The model is formulated in 4+3 dimensions compactified on a manifold S^3/Z_n. Symmetry breaking by Wilson lines is…
Using two simple and robust inputs to constrain the mixing matrix of the isosinglet scalar mesons $f_0(1710)$, $f_0(1500)$, $f_0(1370)$, we have shown that in the SU(3) symmetry limit, $f_0(1500)$ becomes a pure SU(3) octet and is…
We present results on the isoscalar form factors including the disconnected contributions, as well as on the strange and charm quark form factors. Using previous results on the isovector form factors, we determine the flavor decomposition…
We introduce a concept of squeezing in collective qutrit systems through a geometrical picture connected to the deformation of the isotropic fluctuations of su(3) operators when evaluated in a coherent state. This kind of squeezing can be…
We present results from a new Monte Carlo simulation for jet fragmentation in QCD and SUSY QCD for large primary energies $\sqrt s$ up to $10^{16}$ GeV. In the case of SUSY QCD the simulation takes into account not only gluons and quarks as…
We present a VMD based model aiming to describe all radiative decays of light mesons. We show that the SU(3) breaking mechanism proposed by Bando, Kugo and Yamawaki (BKY), supplemented by nonet symmetry breaking in the pseudoscalar sector…
The jet fragmentation function describes the longitudinal momentum distribution of hadrons inside a reconstructed jet. We study the jet fragmentation function in proton-proton collisions in the framework of soft-collinear effective theory…
We study perturbative and non-perturbative aspects of heavy-quark fragmentation into hadrons, emphasizing the large-x region, where x is the energy fraction of the detected hadron. We first prove that when the moment index N and the quark…
Within the framework of Soft Collinear Effective Theory, we present calculations of semi-inclusive jet functions and fragmenting jet functions at next-to-leading order (NLO) for both quark- and gluon-initiated jets, for jet algorithms of…
The production of heavy quarkonia is a powerful tool to test our understanding of strong interaction dynamics. It is well-known that the dominant production mechanism for heavy quarkonia with large transverse momentum is fragmentation. In…