CP violation for neutral charmed meson decays to CP eigenstates

CP asymmetries for neutral charmed meson decays to CP eigenstates are carefully studied. The formulas and numerical results are presented. The impact on experiments is briefly discussed.Comment: 7 pages, 1 figure, 1 table, Revte

A real space renormalization group approach to spin glass dynamics

The slow non-equilibrium dynamics of the Edwards-Anderson spin glass model on a hierarchical lattice is studied by means of a coarse-grained description based on renormalization concepts. We evaluate the isothermal aging properties and show how the occurrence of temperature chaos is connected to a gradual loss of memory when approaching the overlap length. This leads to rejuvenation effects in temperature shift protocols and to rejuvenation--memory effects in temperature cycling procedures with a pattern of behavior parallel to experimental observations.Comment: 4 pages, 4 figure

Second Order Power Corrections in the Heavy Quark Effective Theory I. Formalism and Meson Form Factors

In the heavy quark effective theory, hadronic matrix elements of currents between two hadrons containing a heavy quark are expanded in inverse powers of the heavy quark masses, with coefficients that are functions of the kinematic variable $v\cdot v'$. For the ground state pseudoscalar and vector mesons, this expansion is constructed at order $1/m_Q^2$. A minimal set of universal form factors is defined in terms of matrix elements of higher dimension operators in the effective theory. The zero recoil normalization conditions following from vector current conservation are derived. Several phenomenological applications of the general results are discussed in detail. It is argued that at zero recoil the semileptonic decay rates for $B\to D\,\ell\,\nu$ and $B\to D^*\ell\,\nu$ receive only small second order corrections, which are unlikely to exceed the level of a few percent. This supports the usefulness of the heavy quark expansion for a reliable determination of $V_{cb}$.Comment: (34 pages, REVTEX, two postscript figures available upon request), SLAC-PUB-589

Determination of HQET parameter \lambda_1 from Inclusive Semileptonic B Meson Decay Spectrum

We estimate the heavy quark effective theory parameter \lambda_1 from inclusive semileptonic B-meson decay spectrum. By using recent CLEO double lepton tagging data of B -> X e nu, which shows the lepton momentum as low as 0.6 GeV, we extracted \lambda_1 \sim -0.58 GeV^2. We also derived \bar\Lambda \sim 0.46 GeV and |V_{cb}| = 0.041 \pm 0.002.Comment: 13 pages, 3 figures, LaTeX. Typos are corrected, and added one commen

Non-Gaussianity from Inflation

Correlated adiabatic and isocurvature perturbation modes are produced during inflation through an oscillation mechanism when extra scalar degrees of freedom other than the inflaton field are present. We show that this correlation generically leads to sizeable non-Gaussian features both in the adiabatic and isocurvature perturbations. The non-Gaussianity is first generated by large non-linearities in some scalar sector and then efficiently transferred to the inflaton sector by the oscillation process. We compute the cosmic microwave background angular bispectrum, providing a characteristic feature of such inflationary non-Gaussianity,which might be detected by upcoming satellite experiments.Comment: Revised version accepted for publication in Phys. Rev. D. 19 pages, LaTeX fil

Proximity effects and characteristic lengths in ferromagnet-superconductor structures

We present an extensive theoretical investigation of the proximity effects that occur in Ferromagnet/Superconductor ($F/S$) systems. We use a numerical method to solve self consistently the Bogoliubov-de Gennes equations in the continuum. We obtain the pair amplitude and the local density of states (DOS), and use these results to extract the relevant lengths characterizing the leakage of superconductivity into the magnet and to study spin splitting into the superconductor. These phenomena are investigated as a function of parameters such as temperature, magnet polarization, interfacial scattering, sample size and Fermi wavevector mismatch, all of which turn out to have important influence on the results. These comprehensive results should help characterize and analyze future data and are shown to be in agreement with existing experiments.Comment: 24 pages, including 26 figure

B^0 -> phi K_S in SUGRA models with CP violations

We examine the B -> phi K decays within the framework of SUGRA models making use of the improved QCD factorization method of Beneke et al. which allows calculations of non-factorizable contributions. All other experimental constraints (B -> X_S gamma, neutron and electron electric dipole moments, dark matter constraints, etc.) are imposed. We calculate the CP violating parameters S_{phi K_S}, C_{phi K_S} and A_{phi K^{-+}} as well as the branching ratios (BR) of B^0 and B^{+-}, Br[B -> phi K]. We find for the Standard Model(SM) and mSUGRA it is not possible to account for the observed 2.7 sigma deviation between S_{phi K_S} and S_{J/Psi K_S}. In general the BRs are also in 3 sigma disagreement with experiment, except in the parameter region where the weak annihilation terms dominate the decay (and hence where the theory is least reliable). Thus if future data confirm the current numbers, this would represent the first significant breakdown of both the SM and mSUGRA. We show then that adding a SUGRA non-universal A soft breaking left-right term mixing the second and third generations in either the down or up quark sector, all data can be accommodated for a wide range of parameters. The full 6x6 quark mass matrices are used and the SUSY contributions calculated without approximation.Comment: 22 pages, 3 figures. Added references. Minor changes, to be published in Phys. Rev.

Exclusive semileptonic rare decays B−>(B ->_ (K,K^*) \ell^+ \ell^- in supersymmetric theories

The invariant mass spectrum, forward-backward asymmetry, and lepton polarizations of the exclusive processes $B\to K(K^*)\ell^+ \ell^-, \ell=\mu, \tau$ are analyzed under supersymmetric context. Special attention is paid to the effects of neutral Higgs bosons (NHBs). Our analysis shows that the branching ratio of the process \bkm can be quite largely modified by the effects of neutral Higgs bosons and the forward-backward asymmetry would not vanish. For the process \bksm, the lepton transverse polarization is quite sensitive to the effects of NHBs, while the invariant mass spectrum, forward-backward asymmetry, and lepton longitudinal polarization are not. For both \bkt and \bkst, the effects of NHBs are quite significant. The partial decay widths of these processes are also analyzed, and our analysis manifest that even taking into account the theoretical uncertainties in calculating weak form factors, the effects of NHBs could make SUSY shown up.Comment: Several references are added, typo are correcte

Final state interaction and B→KKB\to KK decays in perturbative QCD

We predict branching ratios and CP asymmetries of the $B\to KK$ decays using perturbative QCD factorization theorem, in which tree, penguin, and annihilation contributions, including both factorizable and nonfactorizable ones, are expressed as convolutions of hard six-quark amplitudes with universal meson wave functions. The unitarity angle $\phi_3= 90^o$ and the $B$ and $K$ meson wave functions extracted from experimental data of the $B\to K\pi$ and $\pi\pi$ decays are employed. Since the $B\to KK$ decays are sensitive to final-state-interaction effects, the comparision of our predictions with future data can test the neglect of these effects in the above formalism. The CP asymmetry in the $B^\pm\to K^\pm K^0$ modes and the $B_d^0\to K^\pm K^\mp$ branching ratios depend on annihilation and nonfactorizable amplitudes. The $B\to KK$ data can also verify the evaluation of these contributions.Comment: 13 pages in latex file, 7 figures in ps file

Charm multiplicity and the branching ratios of inclusive charmless b quark decays in the general two-Higgs-doublet models

In the framework of general two-Higgs-doublet models, we calculate the branching ratios of various inclusive charmless b decays by using the low energy effective Hamiltonian including next-to-leading order QCD corrections, and examine the current status and the new physics effects on the determination of the charm multiplicity $n_c$ and semileptonic branching ratio $B_{SL}$. Within the considered parameter space, the enhancement to the ratio $BR(b \to s g)$ due to the charged-Higgs penguins can be as large as a factor of 8 (3) in the model III (II), while the ratio $BR(b \to no charm)$ can be increased from the standard model prediction of 2.49% to 4.91% (2.99%) in the model III (II). Consequently, the value of $B_{SL}$ and $n_c$ can be decreased simultaneously in the model III. The central value of $B_{SL}$ will be lowered slightly by about 0.003, but the ratio $n_c$ can be reduced significantly from the theoretical prediction of $n_c= 1.28 \pm 0.05$ in the SM to $n_c= 1.23 \pm 0.05$, $1.18 \pm 0.05$ for $m_{H^+}=200, 100$ GeV, respectively. We find that the predicted $n_c$ and the measured $n_c$ now agree within roughly one standard deviation after taking into account the effects of gluonic charged Higgs penguins in the model III with a relatively light charged Higgs boson.Comment: 25 pages, Latex file, axodraw.sty, 6 figures. Final version to be published in Phys.Rev.