Time-dependent Dalitz-Plot Analysis of the Charmless Decay B^0 -> K^0S Pi Pi- at BABAR
Author(s) -
J. Ilic
Publication year - 2009
Publication title -
osti oai (u.s. department of energy office of scientific and technical information)
Language(s) - English
Resource type - Reports
DOI - 10.2172/968531
Subject(s) - physics , dalitz plot , cp violation , b factory , pi , electron–positron annihilation , particle decay , hadron , particle physics , order (exchange) , unitarity , b meson , asymmetry , crystallography , meson , analytical chemistry (journal) , nuclear physics , chemistry , biochemistry , finance , chromatography , economics
A time-dependent amplitude analysis of B{sup 0} {yields} K{sub S}{sup 0}{pi}{sup +}{pi}{sup -} decays is performed in order to extract the CP violation parameters of f{sub 0}(980)K{sub S}{sup 0} and {rho}{sup 0}(770)K{sub S}{sup 0} and direct CP asymmetries of K*{sup +}(892){pi}{sup -}. The results are obtained from the final BABAR data sample of (465 {+-} 5)10{sup 6} B{bar B} decays, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The time dependent CP asymmetry for f{sub 0}(980)K{sub S}{sup 0} and {rho}{sup 0}(770)K{sub S}{sup 0} are measured to be S(f{sub 0}(980)K{sub S}{sup 0}) = -0.97 {+-} 0.09 {+-} 0.01 {+-} 0.01, and S({rho}{sup 0}(770)K{sub S}{sup 0}) = 0.67 {+-} 0.20 {+-} 0.06 {+-} 0.04, respectively. In decays to K*{sup +}(892){pi}{sup -} the direct CP asymmetry is found to be A{sub CP}(K*{sup {+-}}(892){pi}{sup {-+}}) = -0.18 {+-} 0.10 {+-} 0.04 {+-} 0.00. The relative phases between B{sup 0} {yields} K*{sup +}(892){pi}{sup -} and {bar B}{sup 0} {yields} K*{sup -}(892){pi}{sup +}, relevant for the extraction of the unitarity triangle angle {gamma}, is measured to be {Delta}{phi}(K*(892){pi}) = (34.9 {+-} 23.1 {+-} 7.5 {+-} 4.7){sup o}, where uncertainties are statistical, systematic and model-dependent, respectively. Fit fractions, direct CP asymmetries and the relative phases of different other resonant modes have also been measured. A new method for extracting longitudinal shower development information from longitudinally unsegmented calorimeters is also presented. This method has been implemented as a part of the BABAR final particle identification algorithm. A significant improvement in low momenta muon identification at BABAR is obtained
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