相关论文: Enhanced Non-local Power Corrections to the B->X_s…
We discuss nonperturbative contributions to the inclusive rare $B$ decays $B\to X_s\gamma$ and $B\to X_s\ell^+\ell^-$. We employ an operator product expansion and the heavy quark effective theory to compute the leading corrections to the…
We calculate nonperturbative ${\cal O}(\Lambda^2_{QCD}/m^2_c)$ corrections to the dilepton invariant mass spectrum and the forward-backward charge asymmetry in $B\to X_se^+e^-$ decay using a heavy quark expansion approach. The method has…
It has recently been pointed out that a new class of subleading shape functions involving B-meson matrix elements of non-local four-quark operators contributes at order Lambda_{QCD}/m_b to B->X_u+l+nu decay distributions in the endpoint…
Recently, it was shown that in inclusive B -> Xs l+ l- decay, an angular decomposition provides three independent (q^2 dependent) observables. A strategy was formulated to extract all measurable Wilson coefficients in B -> Xs l+ l- from a…
We study nonperturbative corrections to the inclusive rare decay B -> X_s l^+ l^- by performing an operator product expansion (OPE) to O(1/m_b^3). The values of the matrix elements entering at this order are unknown and introduce…
We investigate for the first time a certain class of non-factorisable contributions of the four-quark operators ${\cal O}_{3-6}$ in the weak effective Hamiltonian to the $\Lambda_b \to \Lambda \ell^+\ell^-$ decay amplitude. We focus on the…
We compute the order 1/m_b^3 nonperturbative contributions to the inclusive differential B\to X_c\ell\bar\nu decay rate. They are parametrized by the expectation values of two local and four nonlocal dimension-six operators. We use our…
In this paper we compute the NLO QCD corrections for the inclusive nonleptonic decay rates of $B$-hadrons at subleading power of the heavy quark expansion. In particular, we discuss the coefficient of the chromomagnetic moment parameter…
We present ``state-of-the-art'' theoretical expressions for the triple differential B->X_u l^- nu decay rate and for the B->X_s gamma photon spectrum, which incorporate all known contributions and smoothly interpolate between the…
We study nonperturbative corrections up to O(1/m_b^3) in the inclusive rare B decay B -> X_s l^+ l^- by performing an operator product expansion. The values of the matrix elements entering at this order are unknown and introduce…
An analytic result for the O(alpha_s corrections to the triple differential B -> X_u l nu decay rate is presented, to leading order in the heavy-quark expansion. This is relevant for computing partially integrated decay distributions with…
Uncertainties in the theoretical prediction for the inclusive $B\to X_s\gamma$ decay rate are discussed. We emphasize that there is no operator product expansion for this process. Nonetheless, some nonperturbative effects involving a…
Theoretical predictions for B decay rates are rewritten in terms of the Upsilon meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency is shown both at low and high orders. This method…
We discuss order 1/m_b^4 and 1/m_b^5 corrections in inclusive semileptonic decay of a $B$ meson. We identify relevant hadronic matrix elements of dimension seven and eight and estimate them using the ground-state saturation approximation.…
The effects of spectator light quark in decays of heavy mesons are considered, which vanish in the limit of factorization of matrix elements of four-quark operators over the mesons. These effects include the difference of the total widths…
We derive factorization theorems for Lambda_QCD/mb power corrections to inclusive B-decays in the endpoint region, where mX^2 ~mb Lambda_QCD. In B-> Xu e nu our results are for the full triply differential rate. A complete enumeration of…
We investigate the leading power corrections to the decay rates and distributions in the decay $B \rightarrow X_s \ell^+ \ell^- $ in the standard model (SM) using heavy quark expansion (HQE) in $(1/m_b)$ and a phenomenological model…
We apply the operator product expansion to resum the leading nonperturbative corrections to the endpoint region of the lepton spectrum in inclusive semileptonic $B\to X_q\,\ell\,\bar\nu$ decays, taking into account a finite quark mass $m_q$…
We compute non-perturbative contributions to b->s l+ l- that are not explicitly suppressed by powers of the b-quark mass. They are proportional to lambda_2 and arise from an interference between the free-quark amplitude and higher order…
In the heavy-quark limit, the decay spectrum for radiative and semileptonic inclusive B-meson decays is determined by a universal structure function, i.e. the shape function. We study the constraints on the bilocal heavy-quark operator for…