Study of $B\to \psi (2S)K$ and $B\to \psi (2S)K^{*}$(892) Decays

TL;DR

This paper reports the first observations and measurements of branching fractions and polarization in color-suppressed $B$ meson decays to $\psi(2S)$ and kaon states, providing new insights into these decay processes.

Contribution

It presents the first measurements of branching fractions and polarization in specific $B$ meson decays involving $\psi(2S)$, expanding understanding of these rare decay channels.

Findings

Branching fractions measured for four decay modes.

First observation of $B^0 o \psi(2S) K^0$ and $B^+ o \\psi(2S) K^*(892)^+$.

Longitudinal polarization fraction $\Gamma_L / \Gamma = 0.45 \\pm 0.11 \\pm 0.04$.

Abstract

Color-suppressed decays of $B$ mesons to final states with $\psi(2S)$ mesons have been observed with the CLEO detector. The branching fractions for the decays $B^+ \to \psi(2S) K^+$, $B^+ \to \psi(2S) K^*(892)^+$, $B^0 \to \psi(2S) K^0$, and $B^0 \to \psi(2S) K^*(892)^0$ are measured to be (7.8 +- 0.7 +- 0.9) 10^{-4}$, (9.2 +- 1.9 +- 1.2) 10^{-4}$, (5.0 +- 1.1 +- 0.6) 10^{-4}$, and (7.6 +- 1.1 +- 1.0) 10^{-4}$, respectively, where the first uncertainty is statistical and the second is systematic. The first measurement of the longitudinal polarization fraction is extracted from the angular analysis of the $B \to \psi(2S) K^*(892)$ candidates: $\Gamma_L / \Gamma = 0.45 +- 0.11 +- 0.04 $. Our measurements of the decays $B^0 \to \psi(2S) K^0$ and $B^+ \to \psi(2S) K^*(892)^+$ are first observations.