相关论文: Limit on a Right-Handed Admixture to the Weak $b \…
Recent results from the CLEO Collaboration on both inclusive and exclusive radiative $B$ decays are used to constrain the parameter space of two versions of the Left-Right Symmetric Model. In the first scenario, when the left- and…
We extend the Standard Model with the general effective Hamiltonian for the quark level transition $c \to s \ell \nu$ with a complete set of four fermion operators including right-handed neutrinos. The current experimental measurements in…
The V-A structure of the weak interactions leads to definite amplitude hierarchies in exclusive heavy-to-light decays mediated by $b \to (d,s)\gamma$ and $b \to (d,s) \ell \bar{\ell}$. However, the extraction of right-handed currents beyond…
Inclusive semileptonic $B\to X_c \ell \bar{\nu}_\ell$ decays, where $\ell = \mu,e$, are by now standard candles in the determination of the CKM element $|V_{cb}|$. These determinations rely on the heavy-quark expansion and use moments of…
We critically examine the potential to disentangle Standard Model (SM) and New Physics (NP) in $B \to K^* \mu^+\mu^-$ and $B\to K^* e^+ e^-$ decays, focusing on $(i)$ the LHCb anomaly, $(ii)$ the search for right-handed currents, and…
Motivated by a hint in a CMS search for right-handed $W$-bosons in $eejj$ final states, we propose an experimental test of quark-mixing matrices in a general left-right symmetric model, based on counting the numbers of $b$-tags from…
This review addresses the question of the chirality of $b$ quark weak couplings from a theoretical and from a purely phenomenological point of view. Due to their small magnitude $b$ decay couplings are subject to possible large corrections…
We present results for the moments of observed spectra in inclusive semileptonic B-meson decays to charm hadrons Bbar --> X_c l- nubar. Moments of the hadronic-mass and the combined mass-and-energy spectra for different minimum electron or…
We present a measurement of the fraction f+ of right-handed W bosons produced in top quark decays, based on a candidate sample of $t\bar{t}$ events in the lepton+jets decay mode. These data correspond to an integrated luminosity of…
Precision CP violation measurements in rare hadronic B decays could provide clean signatures of parity symmetric new physics, implying the existence of SU(2)_L x SU(2)_R x U(1)_{B-L} x P symmetry at high energies. New contributions to the…
I point out that $B \to X_q \l^+ \l^-$ decays $(q = s, d)$ are sensitive probes of possible violation of CKM unitarity. I compute the decay rates and asymmetries in a minimal extension of the Standard Model containing an additional…
An interesting possibility to ease the tension between various determinations of |V_{ub}| is to allow a small right-handed contribution to the standard model weak current. The present bounds on such a contribution are fairly weak. We…
We discuss the recent developments in inclusive decays of hadrons containing a heavy quark. The subject is approached in a model independent way using an operator product expansion for the time-ordered product of weak currents. We discuss…
Recent lattice determinations of direct CP violation in kaon decays, parametrized by $\epsilon'$, suggest a discrepancy of several sigma between experiment and the standard model. Assuming that this situation is due to new physics, we…
We determine the inclusive B --> Xc l nu branching fraction, the CKM matrix element |Vcb|, and other heavy-quark parameters from a simultaneous fit to moments of the hadronic-mass and lepton-energy distributions in semileptonic B-meson…
Recent measurements of semileptonic $B$-meson decays into $\tau$-leptons are somewhat higher than expected in the standard model. Although the deviations are less than 3$\sigma$, they suggest the possibility of new physics affecting…
We use the early Large Hadron Collider data to set the lower limit on the scale of Left-Right symmetry, by searching for the right-handed charged gauge boson $W_R$ via the final state with two leptons and two jets, for 33/pb integrated…
Strong interactions are addressed in connection to extracting |V_{cb}| and determining heavy quark parameters. A comprehensive approach allows a robust analysis not relying on a 1/m_c expansion; a percent defendable accuracy in |V_{cb}|…
Inclusive semileptonic $B\to X_c \ell\bar{\nu}$ decays can be described in the Heavy Quark Expansion (HQE) and allow for a precision determination of the CKM element $|V_{cb}|$. We calculate the terms of $1/m_b^5$ and derive a ``trace…
We study the effect of a right-handed coupling of quarks to the W-boson on the measurements of |V_ub| and |V_cb|. It is shown that such a coupling can remove the discrepancies between the determinations of |V_ub| from B\to\pi\ell\nu,…