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Title: Measurements of CP-Violating Asymmetries in B^0 toa_1^+(1260) \pi^- Decays

Abstract

The authors present measurements of CP-violating asymmetries in 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 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 CP-violating asymmetry {Alpha}{sub CP}{sup a{sub 1}{pi}} = -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 parameters {Delta}C{sub 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 determine the angle {alpha}{sub eff} = 78.6{sup o} {+-} 7.3{sup o}.

Authors:
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
896928
Report Number(s):
SLAC-PUB-12257
hep-ex/0612050; TRN: US200705%%73
DOE Contract Number:
AC02-76SF00515
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ASYMMETRY; DECAY; STANFORD LINEAR ACCELERATOR CENTER; Experiment-HEP,HEPEX

Citation Formats

Aubert, B. Measurements of CP-Violating Asymmetries in B^0 toa_1^+(1260) \pi^- Decays. United States: N. p., 2007. Web. doi:10.1103/PhysRevLett.98.181803.
Aubert, B. Measurements of CP-Violating Asymmetries in B^0 toa_1^+(1260) \pi^- Decays. United States. doi:10.1103/PhysRevLett.98.181803.
Aubert, B. Fri . "Measurements of CP-Violating Asymmetries in B^0 toa_1^+(1260) \pi^- Decays". United States. doi:10.1103/PhysRevLett.98.181803. https://www.osti.gov/servlets/purl/896928.
@article{osti_896928,
title = {Measurements of CP-Violating Asymmetries in B^0 toa_1^+(1260) \pi^- Decays},
author = {Aubert, B.},
abstractNote = {The authors present measurements of CP-violating asymmetries in 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 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 CP-violating asymmetry {Alpha}{sub CP}{sup a{sub 1}{pi}} = -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 parameters {Delta}C{sub 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 determine the angle {alpha}{sub eff} = 78.6{sup o} {+-} 7.3{sup o}.},
doi = {10.1103/PhysRevLett.98.181803},
journal = {Physical Review Letters},
number = ,
volume = ,
place = {United States},
year = {Fri Jan 05 00:00:00 EST 2007},
month = {Fri Jan 05 00:00:00 EST 2007}
}
  • We present measurements of CP-violating asymmetries in 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 384x10{sup 6} BB pairs collected with the BABAR detector at the PEP-II asymmetric B factory at SLAC. We measure the CP-violating asymmetry A{sub CP}{sup a{sub 1}}{sup {pi}}=-0.07{+-}0.07{+-}0.02, the mixing-induced CP violation parameter S{sub a{sub 1}}{sub {pi}}=0.37{+-}0.21{+-}0.07, the direct CP violation parameter C{sub a{sub 1}}{sub {pi}}=-0.10{+-}0.15{+-}0.09, and the parameters {delta}C{sub a{sub 1}}{sub {pi}}=0.26{+-}0.15{+-}0.07 and {delta}S{sub a{sub 1}}{sub {pi}}=-0.14{+-}0.21{+-}0.06. From these measured quantities we determine the angle {alpha}{sub eff}=78.6 deg. {+-}7.3 deg.
  • No abstract prepared.
  • We present the studies of the decays B{yields}a{sub 1}(1260){pi} and a{sub 1}(1260)K within the framework of QCD factorization. Because of the G-parity, unlike the vector meson, the chiral-odd two-parton light-cone distribution amplitudes of the a{sub 1} are antisymmetric under the exchange of quark and antiquark momentum fractions in the SU(2) limit. The branching ratios for a{sub 1}{pi} modes are sensitive to tree-penguin interference. The resultant B(B{sup 0}{yields}a{sub 1}{sup {+-}}{pi}{sup {+-}}) are in good agreement with the data. However, using the current Cabibbo-Kobayashi-Maskawa angles, {beta}=22.0 deg. and {gamma}=59.0 deg., our results for the mixing-induced parameter S and {alpha}{sub eff} differ frommore » the measurements of the time-dependent CP asymmetries in the decay B{sup 0}{yields}a{sub 1}{sup {+-}}{pi}{sup {+-}} at about the 3.7{sigma} level. This puzzle may be resolved by using a larger {gamma} > or approx. 80 deg. For a{sub 1}K modes, the annihilation topologies give sizable contributions and are sensitive to the first Gegenbauer moment of the leading-twist tensor (chiral-odd) distribution amplitude of the a{sub 1} meson. The B{yields}a{sub 1}K amplitudes resemble the corresponding B{yields}{pi}K ones very much. Taking the ratios of corresponding CP-averaged a{sub 1}K and {pi}K branching ratios, we can extract information relevant to the electroweak penguins and annihilations. The existence of new physics in the electroweak penguin sector and final-state interactions during decays can thus be explored.« less