Related papers: A novel route to V_us
We propose a new method for precise determination of |V_{td} / V_{ub}| from the ratios of branching ratios BR(B -> \rho \nu \bar \nu ) / BR(B ->\rho l \nu ) and BR(B -> \pi \nu \bar \nu ) / BR(B -> \pi l \nu ). These ratios depend only on…
Using BaBar measurements of the inclusive electron spectrum in B->X_u e nu decays and the inclusive photon spectrum in B->X_s gamma decays, we extract the magnitude of the CKM matrix element Vub. The extraction is based on theoretical…
Hadronic tau decay data is used to study the reliability of various finite energy sum rules (FESR's). For intermediate scales (of order 2-3 GeV^2), those FESR's with weights s^k are found to have significant errors, whereas those with…
We study the decays of heavy chiral (t', b') quarks in a four-generation extension of the Standard Model. If the difference between the t' and b' masses is smaller than the W mass, as favored by precision electroweak measurements, then the…
It has been proposed to determine the CKM matrix element |V_ub| in a model-independent way from a combination of rare and semileptonic B and D decays near the zero recoil point. An essential ingredient in such a determination is a heavy…
We use a new compilation of the hadronic $R$-ratio from available data for the process $e^+e^-\to$ hadrons below the charm mass to determine the strong coupling $\alpha_s$, using finite-energy sum rules. Quoting our results at the $\tau$…
We perform a model dependent fit to recent data on charmless hadronic B decays and determine $\gamma$, the phase of $V^*_{ub}$. We find $\gamma = 114^{+25}_{-21}$ degrees, which disfavors the often quoted $\gamma \sim 60^\circ$ at the two…
We present a lattice calculation of the Hadronic Vacuum Polarization (HVP) contribution of the strange and charm quarks to the anomalous magnetic moment of the muon including leading-order electromagnetic corrections. We employ the gauge…
Alternative top quark mass determinations can provide inputs to the world average with orthogonal systematic uncertainties and may help to refine the interpretation of the standard method. Among a number of recent results I focus on the…
We explore a dark-matter model in which there are two dark-matter species nearly degenerate in mass, with epsilon = Delta M/M << 1. The heavier particle undergoes two-body decay with a half-life tau, to the lighter dark-matter particle and…
The strange quark mass is determined from a new QCD Finite Energy Sum Rule (FESR) optimized to reduce considerably the systematic uncertainties arising from the hadronic resonance sector. As a result, the main uncertainty in this…
Charged current semi-leptonic decays of $B$-meson are important for a precise determination of the CKM elements. The CKM elements $|V_{ub}|$ and $|V_{cb}|$ show a discrepancy between the exclusive and inclusive determinations. These…
We study the effects of non-vanishing pseudoscalar masses in $\tau$ decays into three mesons. The hadronic matrix elements are obtained by using the generalized structure of the chiral currents with nonvanishing pseudoscalar masses and…
The element |V_{ub}| of the quark mixing matrix can be extracted with small theoretical uncertainties by combining weighted integrals over the endpoint regions of the lepton spectrum in B -> X_u l nu decays and the photon spectrum in B ->…
The long distance correction to the total decay width of the $\tau^{\pm}\to K^{0}\pi^{\pm}\nu$ decay is calculated in a model independent approach where a discrimination of photons in the Bremmstrahlung process is assumed. This correction…
We report studies of semileptonic decays, B --> X_c l nu, based on a sample of 88 million BB events recorded with the BABAR detector. We have measured four moments of the electron energy distribution and four moments of the hadronic mass…
New physics beyond the Standard Model could well preferentially show up at the LHC in final states with taus. The development of efficient and accurate reconstruction and identification of taus is therefore an important item in the CMS…
Measurements of the rates for the hadronic decays B^+- -> pi K can be used to derive information on the weak phase gamma=arg(V_ub^*) in a largely model-independent way. Hadronic uncertainties can be reduced to the level of nonfactorizable…
Due to its comparatively theoretical ``simplicity'', the decay channel $B\to\rho e \nu$ offers one of the best possibilities to determine the CKM matrix element $|V_{ub}|$ accurately. I present a new calculation of the relevant hadronic…
We use the exclusive baryonic $B$ decays to determine the Cabibbo-Kobayashi-Maskawa (CKM) matrix element $V_{ub}$. From the relation $|V_{ub}|^2/|V_{cb}|^2=({\cal B}_\pi/{\cal B}_D){\cal R}_{ff}$ based on $B^-\to p\bar p \pi^-$ and $\bar…