B-meson B parameter from HQET sum rules
Andrey Grozin (Novosibirsk, IYF)

B^0 - bar{B}^0 oscillations are characterized by the matrix element of a 4-quark operator Q. This matrix element is usually written as the product of its factorized value and the parameter B which describes factorization breaking. It is a non-perturbative quantity, and its value can be obtained from lattice simulations or QCD sum rules. Here we investigate these sum rules in the framework of heavy quark effective theory (HQET) at the leading order in 1/m_b, taking the first alpha_s corrections into account.