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Title: Extraction of |V_ub| with Reduced Dependence on Shape Functions

Abstract

Using BABAR measurements of the inclusive electron spectrum in B {yields} X{sub u}e{nu} decays and the inclusive photon spectrum in B {yields} X{sub s}{gamma} decays, we extract the magnitude of the CKM matrix element V{sub ub}. The extraction is based on several theoretical calculations designed to reduce the theoretical uncertainties by exploiting the assumption that the leading shape functions are the same for all b {yields} q transitions (q is a light quark). The current results agree well with the previous analysis, have indeed smaller theoretical errors, but are presently limited by the knowledge of the photon spectrum and the experimental errors on the lepton spectrum.

Authors:
; ; ; ;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
900600
Report Number(s):
SLAC-PUB-12336
hep-ph/0702072; TRN: US0702344
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: hep-ph
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ELECTRONS; LEPTONS; MATRIX ELEMENTS; PHOTONS; SHAPE; Phenomenology-HEP,HEPEX, HEPPH

Citation Formats

Golubev, Vladimir B., Skovpen, Yuri, I., /Novosibirsk, IYF, Luth, Vera G., and /SLAC. Extraction of |V_ub| with Reduced Dependence on Shape Functions. United States: N. p., 2007. Web.
Golubev, Vladimir B., Skovpen, Yuri, I., /Novosibirsk, IYF, Luth, Vera G., & /SLAC. Extraction of |V_ub| with Reduced Dependence on Shape Functions. United States.
Golubev, Vladimir B., Skovpen, Yuri, I., /Novosibirsk, IYF, Luth, Vera G., and /SLAC. Tue . "Extraction of |V_ub| with Reduced Dependence on Shape Functions". United States. doi:. https://www.osti.gov/servlets/purl/900600.
@article{osti_900600,
title = {Extraction of |V_ub| with Reduced Dependence on Shape Functions},
author = {Golubev, Vladimir B. and Skovpen, Yuri, I. and /Novosibirsk, IYF and Luth, Vera G. and /SLAC},
abstractNote = {Using BABAR measurements of the inclusive electron spectrum in B {yields} X{sub u}e{nu} decays and the inclusive photon spectrum in B {yields} X{sub s}{gamma} decays, we extract the magnitude of the CKM matrix element V{sub ub}. The extraction is based on several theoretical calculations designed to reduce the theoretical uncertainties by exploiting the assumption that the leading shape functions are the same for all b {yields} q transitions (q is a light quark). The current results agree well with the previous analysis, have indeed smaller theoretical errors, but are presently limited by the knowledge of the photon spectrum and the experimental errors on the lepton spectrum.},
doi = {},
journal = {hep-ph},
number = ,
volume = ,
place = {United States},
year = {Tue Mar 06 00:00:00 EST 2007},
month = {Tue Mar 06 00:00:00 EST 2007}
}
  • Using BABAR measurements of the inclusive electron spectrum in B {yields} X{sub u}e{nu} decays and the inclusive photon spectrum in B {yields} X{sub s}{gamma} decays, we extract the magnitude of the CKM matrix element V{sub ub}. The extraction is based on theoretical calculations designed to reduce the theoretical uncertainties by exploiting the assumption that the leading shape functions are the same for all b {yields} q transitions (q is a light quark). The results agree well with the previous analysis, have indeed smaller theoretical errors, but are presently limited by the knowledge of the photon spectrum and the experimental errorsmore » on the lepton spectrum.« less
  • Using BABAR measurements of the inclusive electron spectrum in B{yields}X{sub u}e{nu} decays and the inclusive photon spectrum in B{yields}X{sub s}{gamma} decays, we extract the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element V{sub ub}. The extraction is based on theoretical calculations designed to reduce the theoretical uncertainties by exploiting the assumption that the leading shape functions are the same for all b{yields}q transitions (q is a light quark). The results agree well with the previous analysis, have indeed smaller theoretical errors, but are presently limited by the knowledge of the photon spectrum and the experimental errors on the lepton spectrum.
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  • A procedure for determining the interaction tensor orientations and the interaction parameters for mutually oriented electric field gradient (efg) or dipolar and shielding tensors has been developed based upon the magnetic field dependence of the critical frequencies from the polycrystalline nuclear magnetic response (NMR) spectrum. The central transition line shape of half-integer quadrupolar nuclei in the presence of mutually oriented shift anisotropy and second order quadrupolar interaction is discussed for the first time. Analytical expressions for the field dependent critical frequencies have been determined for special orientations when the shift principal /ital Z/ axis lies on the /ital XZ/, /italmore » YZ/, or /ital XY/ plane of the efg (or dipolar) tensor for the first order as well as the second order interactions. The plots resulting from the analytical expressions provide a convenient graphical approach in determining approximate tensorial orientations and interaction parameters through pattern recognition. For general orientations, a numerical procedure has been developed to determine these parameters by iteratively minimizing the squares of the differences of the calculated and the experimental critical frequencies. Higher order perturbation terms can be incorporated in the present treatment. The method is demonstrated by variable field static proton spectra of trichloro--acetic acid at three different fields (1.3, 2.3, 5.2 T). The near-orthogonal orientation between the dipolar and shielding tensors and the interaction parameters obtained from this approach are consistent with those obtained previously from single crystal studies.« less