A Study of Exclusive Nonleptonic Decays of B Mesons into Final States of Strange Mesons and 1S or 2S Charmonia

TL;DR

This paper reports on the measurement of branching fractions of specific B meson decays into charmonium and strange mesons using data from the Fermilab Tevatron, providing new insights into heavy quark bound states and validating theoretical models.

Contribution

First observation of B+ -> psi(2S) K+ and B0 -> psi(2S) K*(892)0 decays at a hadron collider, with measurements supporting factorization predictions.

Findings

Significant signals observed in four B-meson decay channels.

Measured branching fraction ratios are consistent with theoretical predictions.

First hadron collider observations of certain B decay modes.

Abstract

[abridged] Bound states of heavy quarks can serve as a laboratory for inquiry into the behaviour of the fundamental strong and electroweak interactions. This thesis examines observations of B0, B0bar, and B+- mesons produced in proton-antiproton collisions at centre-of-mass energies of sqrt{s}=1.8 TeV. The B-meson decay products are recorded using the Collider Detector at Fermilab (CDF) located on the Tevatron collider at Fermilab, USA. Four B-meson decays and their charge conjugates are studied: B+ -> J/psi K+, B0 -> J/psi K*(892)0, B+ -> psi(2S) K+, and B0 -> psi(2S) K*(892)0. Using a data sample corresponding to a time-integrated luminosity of (109 +- 7)/pb, statistically significant signals are observed in all the channels. Topological similarities between the B decays are exploited to measure the six relative branching fractions (Br) of each channel with respect to the other channels. The ratios involving the B+ -> J/psi K+ mode are Br(B0 -> J/psi K*(892)0) / Br(B+ -> J/psi K+) = 1.76 +- 0.14[stat] +- 0.15[syst], Br(B+ -> psi(2S) K+) / Br(B+ -> J/psi K+) = 0.558 +- 0.082[stat] +- 0.056[syst], and Br(B0 -> psi(2S) K*(892)0) / Br(B+ -> J/psi K+) = 0.908 +- 0.194[stat] +- 0.100[syst]. The indicated uncertainties are statistical and systematic, respectively. In ratios involving unlike B-meson species, equal production rates for B+ and B0 mesons have been assumed. The B+ -> psi(2S) K+ and B0 -> psi(2S) K*(892)0 reconstructions are the first observations of these processes at a hadron collider. The branching-fraction ratio measurements are consistent with phenomenological predictions that employ the factorization Ansatz, and the derived absolute branching-fraction measurements are consistent with previous world-average limits and values from e+e- colliders. [abridged]