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Title: Measurement of the Branching Fraction And Search for Direct CP-Violation in the B+- --> J/Psi Pi+- Decay Mode at BaBar

Abstract

The phenomenon of CP-violation in weak interactions, discovered in 1964 in decays of neutral kaons, receives a simple and elegant explanation in the Standard Model with three generations of quarks. Indeed, in this model the common source of CP-asymmetry phenomena is represented by a simple complex phase in the unitary matrix (the Cabibbo-Kobayashi-Maskawa matrix) describing the charged weak couplings of the quarks. This simple scheme has never received an accurate validation, because the phenomenological parameters determined from measurements of CP-violation in kaons decays are related to the fundamental parameters of the theory in a complex way, sensitive to large theoretical uncertainties. On the contrary, decays of neutral B mesons like B{sup 0} {yields} J/{psi} K{sub S}{sup 0} represent a unique laboratory to test the predictions of the theory because they are expected to show significant CP-violation effects, the magnitude of which is cleanly related to the Standard Model parameters. Thus experimental facilities have been built with the purpose of performing extensive studies of B decays. The BABAR experiment is operating at one of these facilities, at the Stanford Linear Accelerator Center. It is collecting data at the PEP-II asymmetric e{sup +}e{sup -} collider (E{sub e{sup -}} = 9.0 GeV; E{submore » e{sup +}} = 3.1 GeV), a high-luminosity accelerator machine (L = 3 x 10{sup 33} cm{sup -2}s{sup -1}). The center-of-mass energy (10.58 GeV) of the e{sup +}e{sup -} system at PEP-II allows resonant production of the {Upsilon}(4S), a b{bar b} bound state, which decays almost exclusively in a B{sup 0}{bar B}{sup 0} or a B{sup +}B{sup -} pair. A high-acceptance detector, projected and built by a wide international collaboration, detects and characterizes the decay products of the B mesons. From the analysis of the data collected during the first two years of operation, the BABAR collaboration has established CP-violation in decays of neutral B mesons at the 4.1{sigma} level. Besides the primary goal of CP-violation studies, the high luminosity of PEP-II, coupled with the high acceptance of the BABAR detector, allows competitive studies of the properties of a wide set of B decay modes. In particular, measurements of non-leptonic decays are extremely useful to understand the dynamics of the non-perturbative strong interactions involved in these processes. In this thesis a study of the non-leptonic decay mode B{sup {+-}} {yields} J/{psi}{pi}{sup {+-}} is presented.« less

Authors:
Publication Date:
Research Org.:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
890245
Report Number(s):
SLAC-R-837
TRN: US0604787
DOE Contract Number:  
AC02-76SF00515
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATORS; B MESONS; BOUND STATE; DAUGHTER PRODUCTS; DECAY; KAONS; LUMINOSITY; PRODUCTION; QUARKS; STANDARD MODEL; STANFORD LINEAR ACCELERATOR CENTER; STRONG INTERACTIONS; VALIDATION; WEAK HADRONIC DECAY; WEAK INTERACTIONS; Experiment-HEP,HEPEX

Citation Formats

Fobozzi, Francesco, and /Naples U. Measurement of the Branching Fraction And Search for Direct CP-Violation in the B+- --> J/Psi Pi+- Decay Mode at BaBar. United States: N. p., 2006. Web. doi:10.2172/890245.
Fobozzi, Francesco, & /Naples U. Measurement of the Branching Fraction And Search for Direct CP-Violation in the B+- --> J/Psi Pi+- Decay Mode at BaBar. United States. https://doi.org/10.2172/890245
Fobozzi, Francesco, and /Naples U. 2006. "Measurement of the Branching Fraction And Search for Direct CP-Violation in the B+- --> J/Psi Pi+- Decay Mode at BaBar". United States. https://doi.org/10.2172/890245. https://www.osti.gov/servlets/purl/890245.
@article{osti_890245,
title = {Measurement of the Branching Fraction And Search for Direct CP-Violation in the B+- --> J/Psi Pi+- Decay Mode at BaBar},
author = {Fobozzi, Francesco and /Naples U.},
abstractNote = {The phenomenon of CP-violation in weak interactions, discovered in 1964 in decays of neutral kaons, receives a simple and elegant explanation in the Standard Model with three generations of quarks. Indeed, in this model the common source of CP-asymmetry phenomena is represented by a simple complex phase in the unitary matrix (the Cabibbo-Kobayashi-Maskawa matrix) describing the charged weak couplings of the quarks. This simple scheme has never received an accurate validation, because the phenomenological parameters determined from measurements of CP-violation in kaons decays are related to the fundamental parameters of the theory in a complex way, sensitive to large theoretical uncertainties. On the contrary, decays of neutral B mesons like B{sup 0} {yields} J/{psi} K{sub S}{sup 0} represent a unique laboratory to test the predictions of the theory because they are expected to show significant CP-violation effects, the magnitude of which is cleanly related to the Standard Model parameters. Thus experimental facilities have been built with the purpose of performing extensive studies of B decays. The BABAR experiment is operating at one of these facilities, at the Stanford Linear Accelerator Center. It is collecting data at the PEP-II asymmetric e{sup +}e{sup -} collider (E{sub e{sup -}} = 9.0 GeV; E{sub e{sup +}} = 3.1 GeV), a high-luminosity accelerator machine (L = 3 x 10{sup 33} cm{sup -2}s{sup -1}). The center-of-mass energy (10.58 GeV) of the e{sup +}e{sup -} system at PEP-II allows resonant production of the {Upsilon}(4S), a b{bar b} bound state, which decays almost exclusively in a B{sup 0}{bar B}{sup 0} or a B{sup +}B{sup -} pair. A high-acceptance detector, projected and built by a wide international collaboration, detects and characterizes the decay products of the B mesons. From the analysis of the data collected during the first two years of operation, the BABAR collaboration has established CP-violation in decays of neutral B mesons at the 4.1{sigma} level. Besides the primary goal of CP-violation studies, the high luminosity of PEP-II, coupled with the high acceptance of the BABAR detector, allows competitive studies of the properties of a wide set of B decay modes. In particular, measurements of non-leptonic decays are extremely useful to understand the dynamics of the non-perturbative strong interactions involved in these processes. In this thesis a study of the non-leptonic decay mode B{sup {+-}} {yields} J/{psi}{pi}{sup {+-}} is presented.},
doi = {10.2172/890245},
url = {https://www.osti.gov/biblio/890245}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Tue Aug 22 00:00:00 EDT 2006},
month = {Tue Aug 22 00:00:00 EDT 2006}
}