Related papers: A sum rule from the shape function
We calculate the electron spectrum of semileptonic decays of B-mesons into non-charmed hadrons. The shape of the spectrum obtained from QCD sum rules is in general agreement with quark model calculations. At high electron energies the…
The $b \to c$ semileptonic sum rules provide relations between the decay rates of $B \to D^{(*)} \tau\bar\nu$ and $\Lambda_b \to \Lambda_c \tau\bar\nu$. Starting from the heavy quark and zero-recoil limits, we revisit the derivation of the…
We study semileptonic sum rules for $b \to c \tau \overline{\nu}$ transitions involving orbitally excited charm hadrons. Starting from the amplitude-level relation implied by the heavy quark symmetry, we construct sum rules relating these…
A precise determination of |V_{ub}| can be obtained exploiting the sum rule for inclusive charmless semileptonic B-meson decays. The sum rule is derived on the basis of light-cone expansion and b-flavored quantum number conservation. The…
We investigate semileptonic sum rules in heavy-to-light charm decays, motivated by analogous relations in $b \to c$ and $b \to u$ transitions. Focusing on the $c \to d\overline{\ell}\nu$ decays, $D \to \pi\overline{\ell}\nu$, $D \to…
We consider the decay of a heavy flavour into an inclusive hadronic state X of invariant mass m_X small with respect to its energy E_X, m_X << E_X. The electron spectrum and the hadronic mass distribution in semileptonic b -> u decays, or…
We perform factorization of the most general distribution in semileptonic B -> X_u decays and we resum the threshold logarithms to next-to-leading order. From this (triple-differential) distribution, any other distribution is obtained by…
A shape-function independent relation is derived between the partial B->X_u+l+nu decay rate with a cut on P_+=E_X-P_X<Delta and a weighted integral over the normalized B->X_s+gamma photon-energy spectrum. The leading-power contribution to…
We show that most spectra in the semileptonic decay B -> X_u + l + nu, such as for example the distribution in the light-cone momentum p_+ = E_X - p_X recently considered, do not have the same long-distance structure of the photon spectrum…
A field theoretic description for inclusive semileptonic B meson decays is formulated. We argue that large regions of the phase spaces for the decays are dominated by distances near the light cone. The light-cone dominance allows to…
Lepton flavor universality is a key prediction of the Standard Model of particle physics and any violation of it immediately indicates the existence of new physics. Given the recent more than $4\sigma$ discrepancy in charged current…
It is argued that the dominant subleading shape-function contributions to the endpoint region of the charged-lepton energy spectrum in B -> X_u l nu decays can be related in a model-independent way to an integral over the B -> X_s gamma…
A sum rule is derived for elastic scattering of hadrons at high energies which is in good agreement with experimental data on $p\bar{p}$ available upto the maximum energy $\sqrt{s} = 2 TeV$. Physically, our sum rule reflects the way…
We show how radiative QCD corrections calculated in terms of quarks can be incorporated at the hadron level in inclusive semileptonic B-meson decays. The bound state effects are described by a momentum distribution function of the $b$…
We resum to next-to-leading order the distribution in the ratio of the invariant hadron mass mX to the total hadron energy EX and the distribution in mX in the semileptonic decays B -> Xu l nu. By expanding our formulas, we obtain the…
Sum rules originally derived for the M\"ossbauer Effect are applied to weak semileptonic B decays. The sum rules follow from assuming that the decay by electroweak boson emission of an unstable nucleus or heavy quark in a bound system is…
We investigate the $b\to c$ semileptonic sum rule in the presence of a massive sterile neutrino. Recent measurements of charged-current semitauonic $B$-meson decays exhibit a $\sim4\sigma$ deviation from the Standard Model predictions,…
We study the semileptonic branching fraction of $B$-meson into higher resonance of charmed meson $D^{**}$ by using the Bjorken sum rule and the heavy quark effective theory(HQET). This sum rule and the current experiment of $B$-meson…
Under the assumption of total absorption and dominance of the imaginary part of the scattering amplitude, we present a sum rule for any hadronic elastic differential cross-section ${d\sigma}\over{dt}$: the dimensionless quantity…
By considering that the weak currents and the electromagnetic current are members of the same SU(3) octet, two sum rules involving leading vector form factors in hyperon semileptonic decays are derived in the limit of exact flavor SU(3)…