Measurement of branching fractions of B decays to K [subscript 1] (1270) pi and K [subscript 1] (1400) pi and determination of the CKM angle Alpha from B [superscript 0]--> a [subscript 1] (1260) (+/-) pi (-/+)

• Main Authors: Fisher, Peter H. (Contributor), Dujmic, Denis (Contributor), Henderson, Shawn Wesley (Contributor), Sciolla, Gabriella (Contributor), Spitznagel, Michael (Contributor), Zhao, Min Liang (Contributor), Yamamoto, Richard K. (Contributor), Cowan, Ray Franklin (Author)
• Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor), Cowan, Ray Frankliin (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2010-09-22T20:45:18Z.
• Subjects: Article
• Online Access: Get fulltext

We report measurements of the branching fractions of neutral and charged B meson decays to final states containing a K1(1270) or K1(1400) meson and a charged pion. The data, collected with the BABAR detector at the SLAC National Accelerator Laboratory, correspond to 454×106 BB̅ pairs produced in e+e- annihilation. We measure the branching fractions B(B0→K1(1270)+π-+K1(1400)+π-)=3.1-0.7+0.8×10-5 and B(B+→K1(1270)0π++K1(1400)0π+)=2.9-1.7+2.9×10-5 (<8.2×10-5 at 90% confidence level), where the errors are statistical and systematic combined. The B0 decay mode is observed with a significance of 7.5σ, while a significance of 3.2σ is obtained for the B+ decay mode. Based on these results, we estimate the weak phase α=(79±7±11)° from the time-dependent CP asymmetries in B0→a1(1260)±π∓ decays.
National Science Foundation (U.S.)
United States. Dept. of Energy
Natural Sciences and Engineering Research Council of Canada
France. Commissariat à l'Energie Atomique
Institut national de physique nucléaire et de physique des particules
Germany. Bundesministerium für Bildung und Forschung
Deutsche Forschungsgemeinschaft
Istituto nazionale di fisica nucleare
Stichting voor Fundamenteel Onderzoek der Materie
Norges forskningsråd
Russia (Federation). ǂb Ministerstvo obrazovanii︠a︡ i nauki
Spain. Ministerio de Educación y Ciencia
Science and Technology Facilities Council (Great Britain)
Marie Curie International Fellowship
Alfred P. Sloan Foundation