Heavy --> Light semileptonic decays of pseudoscalar mesons from lattice QCD

We have computed the form factors for B --> pi and D --> K(pi) semileptonic decays on the lattice by using full non-perturbative O(a) improvement, in the quenched approximation. Our results are expressed in terms of few parameters which describe the q^2-dependence and normalization of the form factors.Comment: 28 pages (LaTeX2e), 11 PostScript figures (version to appear in Nucl.Phys.B

Annihilation Contributions in B -> K_1 gamma decay in next-to-leading order in LEET and CP-asymmetry

The effect of weak annihilation and u-quark penguin contribution on the branching ratio B -> K_1 gamma at next-to-leading order of alpha_s are calculated using LEET approach. It is shown that the value of LEET form factor remains the same in the range of unitarity triangle phase alpha favored by the Standard Model. CP-asymmetry for above mentioned decay has been calculated and its suppression due to the hard spectator correction has also been incorporated. In addition, the sensitivity of the CP-asymmetry on the underlying parameters has been discussed.Comment: 12 pages, 10 figure

Top Squarks and Bottom Squarks in the MSSM with Complex Parameters

We present a phenomenological study of top squarks (~t_1,2) and bottom squarks (~b_1,2) in the Minimal Supersymmetric Standard Model (MSSM) with complex parameters A_t, A_b, \mu and M_1. In particular we focus on the CP phase dependence of the branching ratios of (~t_1,2) and (~b_1,2) decays. We give the formulae of the two-body decay widths and present numerical results. We find that the effect of the phases on the (~t_1,2) and (~b_1,2) decays can be quite significant in a large region of the MSSM parameter space. This could have important implications for (~t_1,2) and (~b_1,2) searches and the MSSM parameter determination in future collider experiments. We have also estimated the accuracy expected in the determination of the parameters of ~t_i and ~b_i by a global fit of the measured masses, decay branching ratios and production cross sections at e^+ e^- linear colliders with polarized beams. Analysing two scenarios, we find that the fundamental parameters apart from A_t and A_b can be determined with errors of 1% to 2%, assuming an integrated luminosity of 1 ab^-1 and a sufficiently large c.m.s. energy to produce also the heavier ~t_2 and ~b_2 states. The parameter A_t can be determined with an error of 2 - 3%, whereas the error on A_b is likely to be of the order of 50%.Comment: 31 pages, 8 figures, comments and references added, conclusions unchanged; version to appear in Phys. Rev.

Exploring flavor structure of supersymmetry breaking from rare B decays and unitarity triangle

We study effects of supersymmetric particles in various rare B decay processes as well as in the unitarity triangle analysis. We consider three different supersymmetric models, the minimal supergravity, SU(5) SUSY GUT with right-handed neutrinos, and the minimal supersymmetric standard model with U(2) flavor symmetry. In the SU(5) SUSY GUT with right-handed neutrinos, we consider two cases of the mass matrix of the right-handed neutrinos. We calculate direct and mixing-induced CP asymmetries in the b to s gamma decay and CP asymmetry in B_d to phi K_S as well as the B_s--anti-B_s mixing amplitude for the unitarity triangle analysis in these models. We show that large deviations are possible for the SU(5) SUSY GUT and the U(2) model. The pattern and correlations of deviations from the standard model will be useful to discriminate the different SUSY models in future B experiments.Comment: revtex4, 36 pages, 10 figure

First Observation of barB0 to D*0 pi+pi+pi-pi- Decays

We report on the observation of B0bar -> D*0 pi+ pi+ pi- pi- decays. The branching ratio is (0.30 +/- 0.07 +/- 0.06)%. Interest in this particular mode was sparked by Ligeti, Luke and Wise who propose it as a way to check the validity of factorization tests in B0bar -> D*+ pi+ pi- pi- pi0 decays.Comment: 11 pages postscript, also available through http://w4.lns.cornell.edu/public/CLNS, Version to appear in Phys. Rev.

Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation

The current status of electric dipole moments of diamagnetic atoms which involves the synergy between atomic experiments and three different theoretical areas -- particle, nuclear and atomic is reviewed. Various models of particle physics that predict CP violation, which is necessary for the existence of such electric dipole moments, are presented. These include the standard model of particle physics and various extensions of it. Effective hadron level combined charge conjugation (C) and parity (P) symmetry violating interactions are derived taking into consideration different ways in which a nucleon interacts with other nucleons as well as with electrons. Nuclear structure calculations of the CP-odd nuclear Schiff moment are discussed using the shell model and other theoretical approaches. Results of the calculations of atomic electric dipole moments due to the interaction of the nuclear Schiff moment with the electrons and the P and time-reversal (T) symmetry violating tensor-pseudotensor electron-nucleus are elucidated using different relativistic many-body theories. The principles of the measurement of the electric dipole moments of diamagnetic atoms are outlined. Upper limits for the nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained combining the results of atomic experiments and relativistic many-body theories. The coefficients for the different sources of CP violation have been estimated at the elementary particle level for all the diamagnetic atoms of current experimental interest and their implications for physics beyond the standard model is discussed. Possible improvements of the current results of the measurements as well as quantum chromodynamics, nuclear and atomic calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for EPJ

Higgs and neutrino sector, EDM and epsilon_K in a spontaneously CP and R-parity breaking supersymmetric model

We construct an extension of the supersymmetric standard model where both CP symmetry and R-parity are spontaneously broken. We study the electroweak symmetry breaking sector of the model and find minima consistent with the experimental bounds on Higgs boson masses. Neutrino masses and mixing angles are generated through both seesaw and bilinear R-parity violation. We show that the hierarchical mass pattern is obtained, and mixings are consistent with measured values. Due to the spontaneous CP and R-parity violation, the neutrino sector is CP violating, and we calculate the corresponding phase. We further restrict the parameter space to agree with the limits on the electric dipole moment of the neutron. Finally, we study the CP violation parameter epsilon_K in the kaon system and show that we obtain results consistent with the experimental value.Comment: 13 pages, 7 figures, submitted to EPJ

CP violation

The salient features of CP-violating interactions in the standard electroweak theory and in a few of its popular extensions are discussed. Moreover a brief overview is given on the status and prospects of searches for CP non-conservation effects in low and high energy experiments.Comment: 28 pages, Lectures given at the 37th Winter School on Particle Physics, Schladming, Austria, 199

Search for single production of a heavy vector-like T quark decaying to a Higgs boson and a top quark with a lepton and jets in the final state

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