Observation of B{sup 0}{yields}ppK*{sup 0} with a Large K*{sup 0} Polarization

Journal Article · Fri Jun 27 04:00:00 EDT 2008 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.100.251801· OSTI ID:21134067

Chen, J -H; Wang, M -Z; Chao, Y; Chen, K -F; Hou, W -S; Hsiung, Y B; Shiu, J -G; Ueno, K; Wang, C C ^[1]; Adachi, I; Haba, J; Hazumi, M; Itoh, R; Katayama, N; Kichimi, H; Krokovny, P; Nakao, M; Nishida, S; Ozaki, H; Sakai, Y ^[2]

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1. Department of Physics, National Taiwan University, Taipei (China)
2. High Energy Accelerator Research Organization (KEK), Tsukuba (Japan)

Using a 492 fb{sup -1} data sample collected near the {upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider, we observe the decay B{sup 0}{yields}ppK*{sup 0} with a branching fraction of (1.18{sub -0.25}{sup +0.29}(stat){+-}0.11(syst))x10{sup -6}. We study the decay dynamics of B{sup 0}{yields}ppK*{sup 0} and compare with B{sup +}{yields}ppK*{sup +}. The K*{sup 0} meson is found to be almost 100% polarized (with a fraction of (101{+-}13{+-}3)% in the helicity zero state), while the K*{sup +} meson has a (32{+-}17{+-}9)% fraction in the helicity zero state. The direct CP asymmetries for B{sup 0}{yields}ppK*{sup 0} and B{sup +}{yields}ppK*{sup +} are measured to be -0.08{+-}0.20{+-}0.02 and -0.01{+-}0.19{+-}0.02, respectively. In addition, we report improved measurements of the branching fractions B(B{sup +}{yields}ppK*{sup +})=(3.38{sub -0.60}{sup +0.73}{+-}0.39)x10{sup -6} and B(B{sup 0}{yields}ppK{sup 0})=(2.51{sub -0.29}{sup +0.35}{+-}0.21)x10{sup -6}, which supersede our previous measurements.

• OSTI ID: 21134067
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 25 Vol. 100; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ASYMMETRY
B NEUTRAL MESONS
BRANCHING RATIO
HELICITY
PAIR PRODUCTION
PARTICLE DECAY
POLARIZATION
RESONANCE