Measurement and Interpretation of Moments of the Combined Hadronic Mass and Energy Spectrum in Inclusive Semileptonic B-Meson Decays

PDF Version Also Available for Download.

Description

This thesis presents first measurements of moments of the hadronic n{sub X}{sup 2} distribution measured in inclusive semileptonic decays of B mesons to final states containing a charm quark, B {yields} X{sub c}{ell}{nu}. The variable n{sub X}{sup 2} is a combination of the invariant mass of the charmed meson m{sub X}, its energy in the B-meson rest-frame E{sub X;BRF}, and a constant {tilde {Lambda}} = 0.65 GeV, n{sub X}{sup 2} = m{sub X}{sup 2}c{sup 4}-2{tilde {Lambda}}E{sub X,BRF} + {tilde {Lambda}}{sup 2}. The moments <n{sub X}{sup k}> with k = 2,4,6 are measured as proposed by theory to constrain assumptions made … continued below

Physical Description

159 pages

Creation Information

Klose, Verena August 12, 2011.

Context

This thesis or dissertation is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by the UNT Libraries Government Documents Department to the UNT Digital Library, a digital repository hosted by the UNT Libraries. It has been viewed 15 times. More information about this document can be viewed below.

Who

People and organizations associated with either the creation of this thesis or dissertation or its content.

Author

Sponsor

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this thesis or dissertation. Follow the links below to find similar items on the Digital Library.

Description

This thesis presents first measurements of moments of the hadronic n{sub X}{sup 2} distribution measured in inclusive semileptonic decays of B mesons to final states containing a charm quark, B {yields} X{sub c}{ell}{nu}. The variable n{sub X}{sup 2} is a combination of the invariant mass of the charmed meson m{sub X}, its energy in the B-meson rest-frame E{sub X;BRF}, and a constant {tilde {Lambda}} = 0.65 GeV, n{sub X}{sup 2} = m{sub X}{sup 2}c{sup 4}-2{tilde {Lambda}}E{sub X,BRF} + {tilde {Lambda}}{sup 2}. The moments <n{sub X}{sup k}> with k = 2,4,6 are measured as proposed by theory to constrain assumptions made in the theoretical description of inclusive observables in semileptonic B-meson decays. This description uses Heavy Quark Expansion (HQE), an effective QCD combined with an Operator Product Expansion. The measurement is based on a sample of 231.6 million e{sup +}e{sup -} {yields} {Upsilon}(4S) {yields} B{bar B} events recorded with the BABAR experiment at the PEP-II e{sup +}e{sup -}-storage rings at SLAC. We reconstruct the semileptonic decay by identifying a charged lepton in events tagged by a fully reconstructed hadronic decay of the second B meson. Correction procedures are derived from Monte Carlo simulations to ensure an unbiased measurement of the moments of the n{sub X}{sup 2} distribution. All moments are measured requiring minimum lepton momenta between 0.8 GeV/c and 1.9 GeV/c in the rest frame of the B meson. Performing a simultaneous fit to the measured moments <n{sub X}{sup k}> up to order k = 6 combined with other measurements of moments of the lepton-energy spectrum in decays B {yields} X{sub c}{ell}{nu} and moments of the photon-energy spectrum in decays B {yields} X{sub s}{gamma}, we determine the quark-mixing parameter |V{sub cb}|, the bottom and charm quark masses, the semileptonic branching fraction {Beta}(B {yields} X{sub c}{ell}{nu}), and four non-perturbative heavy quark parameters. Using HQE calculations in the kinetic scheme up to order 1/m{sub b}{sup 3} we find |V{sub cb}| = (41.65 {+-} 0.43 {+-} 0.40 {+-} 0.58) {center_dot} 10{sup -3} and m{sub b} = (4.570 {+-} 0.033 {+-} 0.043) GeV/c{sup 2}, where the first uncertainty refers to experimental contributions, the second to uncertainties in the HQE, and the third to theoretical uncertainties in the calculations of the semileptonic decay rate {Lambda}(B {yields} X{sub c}{ell}{nu}). All obtained results are consistent with previous determinations. The inclusion of the moments <n{sub X}{sup 6}> decreases the uncertainty on the HQE parameters {mu}{sub {pi}}{sup 2} and {rho}{sub D}{sup 3}. Furthermore, the theoretical treatment of higher order corrections in the HQE used for the moments <m{sub X}{sup k}> has been verified with these new measurements.

Physical Description

159 pages

Language

Identifier

Unique identifying numbers for this document in the Digital Library or other systems.

Collections

This document is part of the following collection of related materials.

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.

What responsibilities do I have when using this thesis or dissertation?

When

Dates and time periods associated with this thesis or dissertation.

Creation Date

  • August 12, 2011

Added to The UNT Digital Library

  • May 19, 2016, 3:16 p.m.

Description Last Updated

  • Aug. 1, 2017, 1:23 p.m.

Usage Statistics

When was this document last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 15

Interact With This Thesis Or Dissertation

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

International Image Interoperability Framework

IIF Logo

We support the IIIF Presentation API

Klose, Verena. Measurement and Interpretation of Moments of the Combined Hadronic Mass and Energy Spectrum in Inclusive Semileptonic B-Meson Decays, thesis or dissertation, August 12, 2011; United States. (https://digital.library.unt.edu/ark:/67531/metadc837509/: accessed May 29, 2024), University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.

Back to Top of Screen