Research Interest

The Standard (Weinberg-Salam) Model unifies the electromagnetic and weak forces into a single theory based on certain symmetries of the fundamental particles, i.e. quarks and leptons. The strong force can also be added to this unified picture if the symmetries are expanded. There have been numerous experimental tests of this model at various high energy accelerator machines at CERN (Geneva), Tevatron (Fermi-Lab) and B factories at SLAC (Stanford) and KEK in Japan, just to name a few, where heavy particles are produced and their decay channels are monitored by ever more sophisticated detectors.

In particle physics phenomenology, one works closely with experiment by using the latest measurement results and checking them against the theoretical expectations. My main research interest is the investigation of the processes involving heavy quarks like charm (m_c=1.5 GeV) and beauty (m_b=4.5 GeV) whose large mass can simplify the theoretical calculations for mesons (quark-antiquark bound states) and baryons (three-quark bound states) that contain at least one of these quarks. For example, since the spin interactions between quarks (spin-1/2 particles) are proportional to 1/m, it can be treated as a small perturbation for heavy quarks. Using this fact and certain experimental data, we were able to predict the ratio of the wavefunctions at the origin for spin zero and spin 1 mesons which consist of charm or beauty quark-antiquarks. The potential model is used to deal with the wavefunctions of η_b(1S), η_c(1S) and their corresponding 2S radial excitations leading to the predictions for the electromagnetic decays of these quarkonium systems. It is interesting to work on the refinements of this method, especially since now experimental data is becoming available, to get better agreement with observations.

Mesons and baryons containing a b quark are particularly interesting as there are a wide variety of available decay modes. Some of these decay modes are rare but if a large number of b-quark hadrons are produced then the rare channels become experimentally accessible. In fact, B factories in the past and LHCb which is currently operational at CERN are built for exactly this purpose. Therefore, rare decays of B, B_s and Λ_b will be measured very soon and those which have already been measured get their experimental error bars reduced. This in turn can provide an excellent venue for precision test of the Standard Model and the new physics beyond it. One of my interests is to calculate these decays, specially those which have a good chance to reveal the signals of possible new physics with as little theoretical uncertainty as possible. Assuming an extra generation of vector quarks is a new physics scenario that I have worked on in the past and have investigated their effects on B meson rare decays.