Study of the decay B0 --> D+ D*- with D*- partial reconstruction

title: Search for leptonic decays of D0 mesons
abstract: We search for the flavor-changing neutral current decays D-0 -> mu(+)mu(-) and D-0 -> e(+)e(-), and for the lepton-flavor violating decays D-0 -> e(+/-)mu(-/+) using 660 fb(-1) of data collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We find no evidence for any of these decays. We obtain significantly improved upper limits on the branching fractions: B(D-0 -> mu(+)mu(-)) e(+)e(-)) e(+)mu(-)) + B(D-0 -> mu(+)e(-)) < 2.6 x 10(-7) at 90% confidence level.

title: Observation of large CP violation in the neutral B meson system.
abstract: We present a measurement of the standard model CP violation parameter sin2 phi(1) based on a 29.1 fb(-1) data sample collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. One neutral B meson is fully reconstructed as a J/psi K(S), psi(2S)K(S), chi(c1)K(S), eta(c)K(S), J/psi K(L), or J/psi K(*0) decay and the flavor of the accompanying B meson is identified from its decay products. From the asymmetry in the distribution of the time intervals between the two B meson decay points, we determine sin2 phi(1) = 0.99+/-0.14(stat)+/-0.06(syst). We conclude that we have observed CP violation in the neutral B meson system.

title: Observation of B+ ---> K(1)(1270)+ gamma

title: Studies of B0 ---> rho+- pi-+ and evidence of B0 ----> rho0 pi0

title: Measurement of branching fractions and charge asymmetries for two-body B meson decays with charmonium
abstract: We report branching fractions and charge asymmetries for exclusive decays of charged and neutral B mesons to two-body final states containing a charmonium meson, J/Ψ or Ψ/(2S). This result is based on a 29.4 fb-1 data sample collected at the Y(4S) resonance with the Belle detector at the KEKB asymmetric e+e- collider.

title: Measurement of charge asymmetries in charmless hadronic B meson decays.
abstract: We search for CP-violating charge asymmetries (alpha(CP)) in the B meson decays to K(+/-)pi(-/+), K(+/-)pi(0), K(0)(S)pi(+/-), K(+/-)eta('), and omega pi(+/-). Using 9.66 million upsilon(4S) decays collected with the CLEO detector, the statistical precision on alpha(CP) is in the range of +/-0.12 to +/-0.25 depending on decay mode. While CP-violating asymmetries of up to +/-0.5 are possible within the standard model, the measured asymmetries are consistent with zero in all five decay modes studied.

title: Origin of power-law X-ray emission in the steep power-law state of X-ray binaries
abstract: We present a new explanation for the origin of the steep power-law (SPL) state of X-ray binaries. The power-law component of X-ray emission is the synchrotron radiation of relativistic electrons in highly magnetized compact spots orbiting near the inner stable circular orbit of a black hole. It has a hard spectrum that extends to above MeV energies, which is determined by the electron acceleration rate. These photons are then down-scattered by the surrounding plasma to form an observed steep spectrum. We discuss the relevance of the model to high-frequency quasi-periodic oscillations and the extremely high luminosity of the SPL state.

title: Study on the Bunch Lengthening and Its Related Instability on BEPC

title: Units and numerical values of the effective couplings in perturbative heterotic string vacua
abstract: We determine the units and numerical values for a class of couplings in the effective theory of perturbative heterotic string vacua, with the emphasis on the correct translation between the canonical gauge coupling g and Planck scale M{sub Planck}{approximately}1.2{times}10{sup 19}GeV as used in the effective theory description and the string coupling g{sub string} and string tension  as used in the S-matrix amplitude calculation. In particular, we determine the effective couplings in the superpotential and reexamine the Fayet-Iliopoulos (FI) term in a class of models with an anomalous U(1). We derive the values of the effective Yukawa couplings (at the third and fourth order) after the restabilization of vacuum along a particular F- and D-flat direction and show that they are {ital comparable} in magnitude. The result corrects results quoted in the literature, and may have implications for the string derived phenomenology, e.g., that of fermion textures.

title: The design study of the BTCF lattice