相关论文: Subleading power corrections in radiative leptonic…
Using methods from soft-collinear and heavy-quark effective theory, a systematic factorization analysis is performed for the $\bar B\to X_s\gamma$ photon spectrum in the endpoint region $m_b-2E_\gamma={\cal O}(\Lambda_{\rm QCD})$. It is…
We compute perturbative QCD corrections to $B \to D$ form factors at leading power in $\Lambda/m_b$, at large hadronic recoil, from the light-cone sum rules (LCSR) with $B$-meson distribution amplitudes in HQET. QCD factorization for the…
We derive the QCD$\times$QED factorization theorem governing the leptonic decay $B^-\to\mu^-\bar\nu_\mu(\gamma)$ at all orders in $\alpha_s$ and $\alpha$. Electromagnetic corrections to this decay probe multiple scales, which we disentangle…
In this work, we study the factorization of the radiative leptonic decays of $B^-$ and $D^-$ mesons, the contributions of the order $O(\Lambda _{\rm QCD}\left/m_Q\right.)$ are taken into account. The factorization is proved to be valid…
The charged lepton spectrum in semileptonic $B\to X_u \ell\bar\nu$ decay near maximal lepton energy receives important corrections from subleading structure functions that are formally suppressed by powers of $\Lambda_{QCD}/m_b$ but are…
We compute the form factors parametrizing radiative leptonic decays of heavy mesons B^+\to\gamma e^+\nu for photon energies much larger than \Lambda_{QCD}, where perturbative QCD methods for exclusive processes can be combined with the…
Motivated by a dynamical enhancement of the electromagnetic corrections by a power of $\Lambda_{\mathrm{QCD}}/m_b$ in $B_{d,s}\, \to\, \mu^+\, \mu^-$ at next-to-leading order (NLO), we extend the QED factorization effects on the leptonic…
We show that the QCD factorization approach for $B$-meson decays to charmless hadronic two-body final states can be extended to include electromagnetic corrections. The presence of electrically charged final-state particles complicates the…
We compute radiative corrections to $\Lambda_b \to \Lambda$ from factors, at next-to-leading logarithmic accuracy, from QCD light-cone sum rules with $\Lambda_b$-baryon distribution amplitudes. Employing the diagrammatic approach…
We summarize recent progress in the theory of exclusive rare and semileptonic B decays, focusing on model-independent results. The heavy-to-light form factors parameterizing these decays admit a model-independent description in two distinct…
We consider the decay $B\to\ell\ell\ell^{\prime}\nu$, taking into account the leading $1/m_b$ and $q^2$ corrections calculated in the QCD factorization framework as well as the soft corrections calculated employing dispersion relations and…
We provide a systematic treatment of the previously discovered power-enhanced QED corrections to the leptonic decay $B_q\to \mu^+\mu^-$ ($q = d, s$) in the framework of soft-collinear effective theory (SCET). Employing two-step matching on…
We calculate the QED and QCD radiative corrections to the charged lepton energy distributions in the dominant semileptonic decays of the top quark $t \to b W^+ \to b(\ell^+ \nu_\ell)$ $(\ell=e, \mu, \tau)$ in the standard model(SM), and for…
We derive a new factorization relation for the semileptonic radiative decay B -> \pi \ell \nu \gamma in the kinematical region of a slow pion p_\pi ~ \Lambda and an energetic photon E_\gamma >> \Lambda, working at leading order in…
The $B$-meson light-cone distribution amplitude is an important non-perturbative quantity arising in the factorization of the amplitudes for many exclusive decays of $B$ mesons, such as $B^-\to\gamma\,\ell^-\bar\nu$. We reconsider the…
In this paper we study the semileptonic decay $B\to\pi l \nu$ and in particular the factorizable contribution to symmetry breaking corrections to the form factors at large recoil. This contribution is a convolution of the coefficient…
We introduce a factorization formula for semi-leptonic $b \to u$ transitions in the exclusive decay mode $B^- \to \pi^+\pi^-\ell^-\bar\nu_\ell$ in the limit of large pion energies and large dipion invariant mass. One contribution can be…
It is by now well known that, at subleading power in scale ratios, factorization theorems for high-energy cross sections and decay amplitudes contain endpoint-divergent convolution integrals. The presence of these divergences hints at a…
We update QCD calculations of $B \to \pi, K$ form factors at large hadronic recoil by including the subleading-power corrections from the higher-twist $B$-meson light-cone distribution amplitudes (LCDAs) up to the twist-six accuracy and the…
I give an overview of the theory of hadronic nonleptonic B decays into two light mesons. Using the soft-collinear effective theory (SCET), a factorization theorem for these processes has been proven to leading order in 1/mb. The…