Alakabha Datta

R parity violating SUSY and CP violation in B ---> phi K(S)

Recent measurements of CP asymmetry in B --> phi K_S appear to be inconsistent with Standard Model expectations. We explore the effect of R-parity-violating SUSY to understand the data.

T-violating triple-product correlations in charmless Λb decays

Abstract Using factorization, we compute, within the standard model, the T-violating triple-product correlations in the charmless decays Λ b → F 1 F 2 , where F 1 is a light spin- 1 2 baryon and F 2 is a pseudoscalar ( P ) or vector ( V ) meson. We find a large triple-product asymmetry of 18% for the decay Λ b → pK − . However, for other classes of Λ b → F 1 P decays, the asymmetry is found to be at most at the percent level. For Λ b → F 1 V decays, we find that all triple-product asymmetries are small (at most O (1%)) for a transversely-polarized V , and are even smaller for longitudinal polarization. Our estimates of the nonfactorizable contributions to these decays show them to be negligible, and we describe ways of testing this.

New-physics effects on triple-product correlations inΛbdecays

We adopt an effective-Lagrangian approach to compute the new-physics contributions to T-violating triple-product correlations in charmless

B→K(∗)K̄(∗) decays: a new method for measuring the CP phase α

{\ensuremath{\Lambda}}_{b}

B -> K(*) Kbar(*) Decays: A New Method for Measuring the CP Phase \alpha

decays. We use factorization and work to leading order in the heavy-quark expansion. We find that the standard-model (SM) predictions for such correlations can be significantly modified. For example, triple products which are expected to vanish in the SM can be enormous

Nonstandard η–η′ mixing and the nonleptonic B and Λb decays to η and η′

(\ensuremath{\sim}50%)

Charmless B decays to final states with radially excited vector mesons

in the presence of new physics. By measuring triple products in a variety of

Measuring sin2β in B0s(t)→φKS

{\ensuremath{\Lambda}}_{b}

Single Top Production and Extra Dimensions

decays, one can diagnose which new-physics operators are or are not present. Our general results can be applied to any specific model of new physics by simply calculating which operators appear in that model.

DIFFICULTIES IN OBTAINING WEAK PHASES FROM b → d PENGUIN DECAYS

We present a new method for measuring the CP phase \alpha. It requires the measurement of the pure penguin decays Bd(t) -> K(*) Kbar(*) and B_s -> K(*) Kbar(*). The method is quite clean: we estimate the theoretical uncertainty to be at most 5%. By applying the method to several K(*) Kbar(*) final states, \alpha can be extracted with a fourfold ambiguity. An additional assumption reduces this ambiguity to twofold: {\alpha, \alpha + \pi}. Since no \pi0 detection is needed, this method can be used at hadron colliders.