B->Kpi ll in and outside the K* window

We study the impact of B->Kpill decays on B->K*(->Kpi)ll, taking into account the K* at finite width. Interference effects can generically be sizable, up to O(10%), but are reduced in several ratios of observables of the angular distribution. Information on strong phases is central to control interference effects, which cannot be removed by sideband subtractions. We point out ways to probe the strong phases; only a single one is required to describe leading effects in the region of low hadronic recoil. We find that recent LHCb data on the B0->K*0mumu angular observables at low recoil are in good agreement with the standard model.

Two-pion low-energy contribution to the muon $g-2$ with improved precision from analyticity and unitarity

The two-pion contribution from low energies to the muon magnetic moment anomaly, although small, has a large relative uncertainty since in this region the experimental data on the cross sections are neither sufficient nor precise enough. It is therefore of interest to see whether the precision can be improved by means of additional theoretical information on the pion electromagnetic form factor, which controls the leading order contribution. In the present paper we address this problem by exploiting analyticity and unitarity of the form factor in a parametrization-free approach that uses the phase in the elastic region, known with high precision from the Fermi-Watson theorem and Roy equations for $pipi$ elastic scattering as input. The formalism also includes experimental measurements on the modulus in the region 0.65-0.70 GeV, taken from the most recent $e^+e^-to pi^+pi^-$ experiments, and recent measurements of the form factor on the spacelike axis. By combining the results obtained with inputs from CMD2, SND, BABAR and KLOE, we make the predictions $a_mu^{pipi, LO},[2 m_pi,, 0.30 gev]=(0.553 pm 0.004) times 10^{-10}$ and $a_mu^{pipi, LO},[0.30 gev,, 0.63 gev]=(133. 083 pm 0.837)times 10^{-10}$. These are consistent with the other recent determinations, and have slightly smaller errors.

Tadpole cancellation in top-quark condensation

We show that quadratic divergences in top-quark condensation are cancelled when the tadpoles cancel. This latter cancellation is naturally implemented as the cancellation among the top-quark, Goldstone and Higgs contributions. We also calculate the bosonic correction terms to Gribovs mass formula for the Higgs boson. These reduce the prediction for M_H from 167 GeV to 132 GeV. The tadpole cancellation condition by itself is an independent condition on the mass of the Higgs boson which, in Gribovs U(1)_Y scenario, yields M_H approx 117 GeV with large theoretical uncertainty. More generally, we are able to obtain all three masses, M_W, m_t and M_H, in 100 MeV to 10 TeV energy range as a function of the cut-off scale and the gauge couplings only.