Content area
Abstract
In this dissertation the matrix element (ME) for the weak decay of the B-meson into J/ψ-particle and a kaon K is analysed from the first principles using the method of effective field theory based on exploiting the decay kinematics. Namely, the large masses of the b- and c-quarks, the large energy of the s-quark in the rest frame of the B-meson makes it reasonable to use HQET, NRQCD, and SCET to express the ME of the decay in terms of the MEs of these theories. The covariant version of NRQCD necessary to describe the J/ψ in the B-meson rest frame is proposed in the dissertation. The tree-level expression for the decay Lagrangian in the effective theory is derived to all orders in gs. The Wilson coefficients for the decay Lagrangian at the leading logarithmic approximation and their initial values at μ = mb are calculated. It is shown that the singlet piece of the decay Lagrangian factorizes into the product of two currents at the leading order in power expansion in the effective theory but the octet piece doesn't. It is shown that the contribution due to the non-factorizable octet piece is of the same order of magnitude as the singlet contribution at μ = mb and it is argued that the octet contribution although suppressed by one power of αs compared to the singlet contribution cannot be ignored.
