Direct Measurement of B(D0->phiX0) and B(D+->phiX+)

TL;DR

This paper reports the first measurements of specific B meson decay branching fractions involving phi mesons at a charm threshold energy, using recoil charge methods on BES data.

Contribution

It introduces a novel recoil charge method for charm threshold data to measure B meson decay branching fractions involving phi mesons.

Findings

Measured B(D0->phiX0) = (1.71+0.76-0.71+-0.17)%

Set an upper limit B(D+->phiX+) < 1.8%

Established a 90% C.L. upper limit for B(D+->phi e+X0) < 1.6%

Abstract

The first measurement of B(0->phi X0) and an upper limit for B(D+->phi X+) are determined from 22.3 pb-1 of e+e- annihilation data at a C. M. energy of 4.03 GeV. The data were recorded by the Beijing Spectrometer (BES) at BEPC. A recoil charge method is applied for the first time to charm threshold data to determine the charge of the D meson in the recoil from 9054+-309+-416 reconstructed D0, D+ mesons. The branching fractions B(D->phiX0) =(1.71+0.76-0.71+-0.17)%, and B(D+->phiX+) <1.8% are determined from 10 events with a reconstructed D and a recoiling phi. In addition, a 90% C.L. upper limit of B(D+->phi e+X0)<1.6% is determined from a search for semileptonic decays of the D+.