# Measurement of the Inclusive B-Lifetime Using $\rm {J/\psi}$'s at the CDF Experiment

### Description

This dissertation describes the measurement of the average B hadron lifetime using a high statistics sample of B → J/ΨX decays produced in p$\bar{p}$ collisions at a center of mass energy of √s = 1.8 TeV at the Fermilab Tevatron. The integrated luminosity of the sample is 10.1 pb<sup>-1</sup> recorded with the Collider Detector at Fermilab (CDF). In this analysis the decay vertex of the decay J/Ψ → μ<sup>+</sup>μ<sup>-</sup> as reconstructed by a silicon vertex detector is used to extract the lifetime from the data. This measurement is the average over all b-hadrons produced weighted by the product of their ... continued below

131 p.

### Creation Information

Wenzel, Hans-Joachim August 1, 1993.

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### Description

This dissertation describes the measurement of the average B hadron lifetime using a high statistics sample of B → J/ΨX decays produced in p$\bar{p}$ collisions at a center of mass energy of √s = 1.8 TeV at the Fermilab Tevatron. The integrated luminosity of the sample is 10.1 pb<sup>-1</sup> recorded with the Collider Detector at Fermilab (CDF). In this analysis the decay vertex of the decay J/Ψ → μ<sup>+</sup>μ<sup>-</sup> as reconstructed by a silicon vertex detector is used to extract the lifetime from the data. This measurement is the average over all b-hadrons produced weighted by the product of their branching ratios into J/Ψ and their production cross sections. We find the following value for the average b hadron lifetime: τ<sub>B</sub> = 1.46 ± 0.06(stat.) ± 0.06(syst.) ps. This is the first measurement of the b-hadron lifetime at a hadron collider. It demonstrates that it is possible to access the large b-quark production cross section in p$\bar{p}$ collisions and to achieve high statistics even in modes which have small product branching ratios as in this case: BR(B → J/ΨX) • BR(J/Ψ → μ<sup>+</sup>μ<sup>-</sup>) = 7.7 x 10<sup>-4</sup>.

131 p.

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• Report No.: FERMILAB-THESIS--1993-67
• Grant Number: AC02-07CH11359
• DOI: 10.2172/992647 | External Link
• Office of Scientific & Technical Information Report Number: 992647

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#### Office of Scientific & Technical Information Technical Reports

Reports, articles and other documents harvested from the Office of Scientific and Technical Information.

Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.

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### Creation Date

• August 1, 1993

### Added to The UNT Digital Library

• Oct. 14, 2017, 8:36 a.m.

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• Oct. 24, 2017, 2:59 p.m.

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Wenzel, Hans-Joachim. Measurement of the Inclusive B-Lifetime Using $\rm {J/\psi}$'s at the CDF Experiment, thesis or dissertation, August 1, 1993; Batavia, Illinois. (digital.library.unt.edu/ark:/67531/metadc1013156/: accessed March 22, 2018), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.