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Title: Observation of B0 Meson Decays to a1(1260)+- pi-+

Abstract

The authors present a measurement of the branching fraction of the decay B{sup 0} {yields} a{sub 1}{sup {+-}}(1260){pi}{sup {-+}} with a{sub 1}{sup {+-}}(1260) {yields} {pi}{sup {-+}}{pi}{sup {+-}}{pi}{sup {+-}}. The data sample corresponds to 218 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation through the {Upsilon}(4S) resonance. The authors measure the branching fraction {Beta}(B{sup 0} {yields} a{sub 1}{sup {+-}}(1260){pi}{sup {-+}}){Beta}(a{sub 1}{sup {+-}}(1260){yields} {pi}{sup {-+}}{pi}{sup {+-}}{pi}{sup {+-}})=(16.6 {+-} 1.9 {+-} 1.5) x 10{sup -6}, where the first error quoted is statistical and the second is systematic.

Authors:
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
878353
Report Number(s):
SLAC-PUB-11769
hep-ex/0603050; TRN: US0602323
DOE Contract Number:
AC02-76SF00515
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; ANNIHILATION; DECAY; MESONS; RESONANCE; Experiment-HEP,HEPEX

Citation Formats

Aubert, B. Observation of B0 Meson Decays to a1(1260)+- pi-+. United States: N. p., 2006. Web. doi:10.2172/878353.
Aubert, B. Observation of B0 Meson Decays to a1(1260)+- pi-+. United States. doi:10.2172/878353.
Aubert, B. Mon . "Observation of B0 Meson Decays to a1(1260)+- pi-+". United States. doi:10.2172/878353. https://www.osti.gov/servlets/purl/878353.
@article{osti_878353,
title = {Observation of B0 Meson Decays to a1(1260)+- pi-+},
author = {Aubert, B.},
abstractNote = {The authors present a measurement of the branching fraction of the decay B{sup 0} {yields} a{sub 1}{sup {+-}}(1260){pi}{sup {-+}} with a{sub 1}{sup {+-}}(1260) {yields} {pi}{sup {-+}}{pi}{sup {+-}}{pi}{sup {+-}}. The data sample corresponds to 218 x 10{sup 6} B{bar B} pairs produced in e{sup +}e{sup -} annihilation through the {Upsilon}(4S) resonance. The authors measure the branching fraction {Beta}(B{sup 0} {yields} a{sub 1}{sup {+-}}(1260){pi}{sup {-+}}){Beta}(a{sub 1}{sup {+-}}(1260){yields} {pi}{sup {-+}}{pi}{sup {+-}}{pi}{sup {+-}})=(16.6 {+-} 1.9 {+-} 1.5) x 10{sup -6}, where the first error quoted is statistical and the second is systematic.},
doi = {10.2172/878353},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Mar 27 00:00:00 EST 2006},
month = {Mon Mar 27 00:00:00 EST 2006}
}

Technical Report:

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  • We report measurements of the branching fractions of neutral and charged B meson decays to final states containing a K{sub 1}(1270) or K{sub 1}(1400) meson and a charged pion. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, correspond to 454 million B{bar B} pairs produced in e{sup +}e{sup -} annihilation. We measure the branching fractions {Beta}(B{sup 0} {yields} K{sub 1}(1270){sup +}{pi}{sup -} + K{sub 1}(1400){sup +}{pi}{sup -}) = 3.1{sub 0.7}{sup +0.8} x 10{sup -5} and {Beta}(B{sup +} {yields} K{sub 1}(1270){sup 0}{pi}{sup +} + K{sub 1}(1400){sup 0}{pi}{sup +}) = 2.9{sub -1.7}{sup +2.9} x 10{sup -5} (<more » 8.2 x 10{sup -5} at 90% confidence level), where the errors are statistical and systematic combined. The B{sup 0} decay mode is observed with a significance of 7.5{sigma}, while a significance of 3.2{sigma} is obtained for the B{sup +} decay mode. Based on these results, we estimate the weak phase {alpha} = (79 {+-} 7 {+-} 11){sup o} from the time dependent CP asymmetries in B{sup 0} {yields} a{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decays.« less
  • The two B{sup 0} decay processes B{sup 0} {yields} D*{sup -} {pi}{sup +} and B{sup 0} {yields} D*{sup -} {ell}{sup +} {nu}{sub {ell}} have been studied by means of a partial reconstruction technique using a data sample collected with the BABAR detector at the PEP-II storage ring. To increase statistics, only the soft {pi}{sup -} from the decay D*{sup -} {yields} {pi}{sup -} D{sup 0} was used in association with either an oppositely-charged high-momentum pion or lepton. Events were then identified by exploiting the constraints from the simple kinematics of {Upsilon}(4S) decays. A clear signature is obtained in each case.more » The position of the B{sup 0} decay point was obtained from the reconstructed {pi}{sup +} ({ell}{sup +}){pi}{sup -} vertex. The position of the other {bar B}{sup 0} in the event was also determined. Taking advantage of the boost given to the {Upsilon}(4S) system by the asymmetric beam energies of PEP-II, the lifetime of the B{sup 0} meson has been measured from the separation distance between the two vertices along the beam direction.« less
  • The neutral B meson lifetime is measured with the data collected by the BABAR detector at the PEP-II storage ring during the years 1999 and 2000, with a total integrated luminosity of 20.7 fb{sup -1}. The decays B{sup 0} {yields} D*{sup -} {pi}{sup +} and B{sup 0} {yields} D*{sup -} {rho}{sup +} are selected with a partial-reconstruction technique, yielding samples of 6970 {+-} 240 and 5520 {+-} 250 signal events, respectively. With these events, the B{sup 0} lifetime is measured to be 1.533 {+-} 0.034 (stat.) {+-} 0.038 (syst.) ps. This measurement serves as a test and validation of proceduresmore » required to measure the CP violation parameter sin (2{beta} + {gamma}) with partial reconstruction of these modes.« less
  • The authors present measurements of CP-violating asymmetries in the decays B{sup 0} {yields} a{sub 1}{sup {+-}}(1260){pi}{sup {-+}} with a{sub 1}{sup {+-}}(1260) {yields} {pi}{sup {-+}}{pi}{sup {+-}}{pi}{sup {+-}}. The data sample corresponds to 384 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the PEP-II asymmetric B-factory at SLAC. They measure the time- and flavor-integrated charge asymmetry A{sub CP}{sup 1{sub 1}{+-}} = -0.07 {+-} 0.07 {+-} 0.02, the mixing-induced CP violation parameter S{sub a{sub 1}{pi}} = 0.37 {+-} 0.21 {+-} 0.07, the direct CP violation parameter C{sub a{sub 1}{pi}} = -0.10 {+-} 0.15 {+-} 0.09, and the parameter {Delta}C{submore » a{sub 1}{pi}} = 0.26 {+-} 0.15 {+-} 0.07 and {Delta}S{sub a{sub 1}{pi}} = -0.14 {+-} 0.21 {+-} 0.06. From these measured quantities they extract the angle {alpha}{sub eff} = 78.6{sup o} {+-} 7.3{sup o}.« less