Abstract:

In this thesis using the semileptonic decay B → K* l+ l ,
it is shown how NP signal can be extracted to all orders in
α(s) in perturbation theory, including ‘nonfactorizable’
corrections at leading order in (Λ(QCD))/m(b) in heavy quark
expansion. Relations between various hadronic form factor
ratios and observables are derived independent of any Wilson
coefficients, which enable the researcher to test these ratios
in experiments. This thesis is divided in to six chapters.
Brief introduction to the theoretical tools needed to study
B physics(the standard model of electroweak interaction)
is given in Chapter 1. Yukawa Lagrangian which encodes
the entire flavour structure of the standard model, are
discussed in this chapter. The phenomenology of B decays
are described in an effective field theory approach called
the Operator Product Expansion (OPE). The hadronic estimates
are based on the heavy quark symmetry which is discussed at
the end of the chapter. The theoretical framework of
B → K* l+ l decay is described in Chapter 2. The angular
distribution of B → K* l+ l is described in Chapter 3.
There are six transversity amplitudes corresponding to
each of three polarization states of K meson with two
chirality of the leptonic current.
A model independent framework to study new physics effects
is developed in Chapter 4.
The low energy approximation of various relations are discussed.
It is shown that these relations can be used to test the
low energy approximation of form factor calculations.
A numerical analysis is presented, in comparing it with the
current experimental data on the B → K* l+ l mode. Also
compared the present approach with the theoretical approach
available in the literature. In this thesis the author has
presented various relations among observables without involving
any form factors and Wilson coefficients The violation of these
relations will be a clean signals of new physics. In addition,
various relations between ratios of form factors and observables
that are free from any Wilson coefficients are derived. 