Measurement of partial branching fractions of inclusive charmless B meson decays to K+, K0, and pi+

TL;DR

This paper measures partial branching fractions of charmless B meson decays to kaons and pions at high momenta, testing for new physics effects in loop transitions, using a large BaBar dataset.

Contribution

First measurement of partial branching fractions for B decays to K and pi at high momenta above charm thresholds, constraining new physics contributions.

Findings

Results agree with Standard Model predictions.

No large enhancements due to new physics observed.

Provides limits on new physics contributions in b→s(d) transitions.

Abstract

We present measurements of partial branching fractions of $B \rightarrow K^+ X$, $B \rightarrow K^0 X$, and $B \rightarrow \pi^+ X$, where $X$ denotes any accessible final state above the endpoint for B decays to charmed mesons, specifically for momenta of the candidate hadron greater than 2.34 (2.36) GeV for kaons (pions) in the B rest frame. These measurements are sensitive to potential new-physics particles which could enter the $b \rightarrow s(d)$ loop transitions. The analysis is performed on a data sample consisting of $383 \times 10^6$ $B \bar{B}$ pairs collected with the BaBar detector at the PEP-II $e^+e^-$ asymmetric energy collider. Our results are in agreement with standard model predictions and exclude large enhancements of the inclusive branching fraction due to sources of new physics.