# Measurement of Inclusive b Semileptonic Branching Fractions at the Z Resonance

## Abstract

This document presents a new measurement of inclusive b semileptonic branching fractions B(b-->l) and B(b-->c-->l). The b-->l and b-->c-->l are separated by a means that uses correlation between the final state lepton charge and that of its parent b quark as a constraint. Monte Carlo counts of electrons and muons are calibrated to the data using a newly developed technique based on pairs of mutually independent tests for each particle hypothesis separately. The data sample consists of about 550,000 hadronic Z decays collected at the SLD between 1993 and 1998. Upon analysis of electron and muon counts in 61602 hadronic event hemispheres tagged as containing either a b or a b-bar, the author reports: B(b-->e) = 0.0949{+-}0.0049{+-}0.0050, B(b-->mu) = 0.1066{+-}0.0038{+-}0.0049, combined B(b-->l) = 0.1015{+-}0.0030{+-}0.0035; and B(b-->c-->e) = 0.0811{+-}0.0053{+-}0.0030, B(-->b-->c-->mu) = 0.0717{+-}0.0045{+-}0.0024, combined B(b-->c-->l) = 0.0756{+-}0.0034{+-}0.0019.

- Authors:

- Publication Date:

- Research Org.:
- Stanford Linear Accelerator Center, Menlo Park, CA (US)

- Sponsoring Org.:
- USDOE Office of Energy Research (ER) (US)

- OSTI Identifier:
- 763780

- Report Number(s):
- SLAC-R-558

TRN: US0004816

- DOE Contract Number:
- AC03-76SF00515

- Resource Type:
- Technical Report

- Resource Relation:
- Other Information: PBD: 23 May 2000

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; SEMILEPTONIC DECAY; BRANCHING RATIO; Z*BARYONS; B QUARKS; HADRONIC PARTICLE DECAY; STANFORD LINEAR COLLIDER DETECTOR; ELECTRONS; MUONS; EXPERIMENTAL DATA

### Citation Formats

```
Trandafir, Aurel.
```*Measurement of Inclusive b Semileptonic Branching Fractions at the Z Resonance*. United States: N. p., 2000.
Web. doi:10.2172/763780.

```
Trandafir, Aurel.
```*Measurement of Inclusive b Semileptonic Branching Fractions at the Z Resonance*. United States. doi:10.2172/763780.

```
Trandafir, Aurel. Tue .
"Measurement of Inclusive b Semileptonic Branching Fractions at the Z Resonance". United States. doi:10.2172/763780. https://www.osti.gov/servlets/purl/763780.
```

```
@article{osti_763780,
```

title = {Measurement of Inclusive b Semileptonic Branching Fractions at the Z Resonance},

author = {Trandafir, Aurel},

abstractNote = {This document presents a new measurement of inclusive b semileptonic branching fractions B(b-->l) and B(b-->c-->l). The b-->l and b-->c-->l are separated by a means that uses correlation between the final state lepton charge and that of its parent b quark as a constraint. Monte Carlo counts of electrons and muons are calibrated to the data using a newly developed technique based on pairs of mutually independent tests for each particle hypothesis separately. The data sample consists of about 550,000 hadronic Z decays collected at the SLD between 1993 and 1998. Upon analysis of electron and muon counts in 61602 hadronic event hemispheres tagged as containing either a b or a b-bar, the author reports: B(b-->e) = 0.0949{+-}0.0049{+-}0.0050, B(b-->mu) = 0.1066{+-}0.0038{+-}0.0049, combined B(b-->l) = 0.1015{+-}0.0030{+-}0.0035; and B(b-->c-->e) = 0.0811{+-}0.0053{+-}0.0030, B(-->b-->c-->mu) = 0.0717{+-}0.0045{+-}0.0024, combined B(b-->c-->l) = 0.0756{+-}0.0034{+-}0.0019.},

doi = {10.2172/763780},

journal = {},

number = ,

volume = ,

place = {United States},

year = {2000},

month = {5}

}