We analyse ∆C = 2 transitions in the framework of a minimal extension of the Standard Model where either a Q = 2/3 or a Q = −1/3 isosinglet quark is added to the standard quark spectrum. In the case of a Q = 2/3 isosinglet quark, it is shown that there is a significant region of parameter space where D 0 − ¯ D 0 mixing is sufficiently enhanced to be observed at the next round of experiments. On...

A search for SUSY using the top quark plus missing transverse energy (MET), in a low mass mSUGRA test point is performed. A two–constraints kinematic fit is utilized to extract the top quark, either b-jet the ones that is recognizable or it is not recognizable. It is shown that for point LM1, for the former situation, a 5σ excess can be achieved with 30 pb-1 and for the latter situation, it can...

The Relativistic Hartree Bogoliubov model in coordinate space, with finite range pairing interaction, is applied to the description of Λ-hypernuclei with a large neutron excess. The addition of the Λ hyperon to Ne isotopes with neutron halo can shift the neutron drip by stabilizing an otherwise unbound core nucleus. The additional binding of the halo neutrons to the core originates from the inc...

Talk based on work entitled “Yukawa textures, new physics and nondecoupling,” done in collaboration with G. C. Branco and J. I. SilvaMarcos, arXiv:hep-ph/0612252, to appear in Phys. Rev. D. In this work we pointed out that New Physics can play an important rôle in rescuing some of the Yukawa texture zero ansätze which would otherwise be eliminated by the recent, more precise measurements of VCK...

Lattice calculations of matrix elements involving heavy-light quark bilinears are of interest in calculating a variety of properties of B and D mesons, including decay constants and mixing parameters. A large source of uncertainty in the determination of these properties has been uncertainty in the normalization of the lattice-regularized operators that appear in the matrix elements. Tadpole-im...

Some properties of intrinsic transverse momentum dependent nucleon distribution functions are considered in the simple quark-diquark model. The transverse target polarization dependent asymmetries for SIDIS are calculated and compared with recent results of COMPASS. The model describes well the measured asymmetries. Generalization of quark-diquark model for Sivers function is discussed.

The HERMES experiment at the DESY Laboratory in Hamburg, Germany is designed to probe the spin structure of the nucleon by using deep inelastic scattering (DIS) of longitudinally polarized positrons on longitudinally and transversely polarized targets. The HERMES spectrometer has the ability to not only identify the scattered DIS positrons but as well the hadrons in coincidence with the scatter...

Processes of heavy quark photoproduction at HERA energies are considered using the semihard (k⊥ factorization) QCD approach with emphasis of the BFKL dynamics of gluon distributions. We investigate the dependences of the total cross section of heavy quark photoproduction and also pT , and rapidity distributions on different forms of the unintegrated gluon distribution. We present a comparision ...

in this research we described the effective hamiltonian theory and applied this theory to the calculation of current-current (q1,2) and qcd penguin (q3,…,6) c quark decay rates. we calculated the decay rates of semileptonic and hadronic of charm quark in the effective hamiltonian theory. we investigated the decay rates of d meson decays according to spectator quark model (sqm) for the calculati...

A formal study of quark models with interactions due to scalar, pseudoscalar or vector fields is presented. It is shown that all the results which have been derived in quark parton models in which the details of the nucleonls constitution are not specified can be obtained formally using naive canonical manipulations of operators. In the case that there is no vector field some new results are ob...