First observation of radiative B{sup 0}{yields}{phi}K{sup 0}{gamma} decays and measurements of their time-dependent CP violation

Journal Article · Sat Oct 01 04:00:00 EDT 2011 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.84.071101· OSTI ID:21607727

Sahoo, H; Browder, T E; Nishimura, K; Vahsen, S E; Varner, G ^[1]; Adachi, I; Haba, J; Itoh, R; Iwasaki, Y; Nakao, M; Nishida, S; Nozaki, T; Sakai, K; Sakai, Y; Sumisawa, K; Trabelsi, K; Uno, S; Ushiroda, Y ^[2]; Asner, D M; Fast, J E ^[3]

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1. University of Hawaii, Honolulu, Hawaii 96822 (United States)
2. High Energy Accelerator Research Organization (KEK), Tsukuba (Japan)
3. Pacific Northwest National Laboratory, Richland, Washington 99352 (United States)

We report the first observation of the radiative decay B{sup 0}{yields}{phi}K{sup 0}{gamma} using a data sample of 772x10{sup 6} BB pairs collected at the {Upsilon}(4S) resonance with the Belle detector at the KEKB asymmetric-energy e{sup +}e{sup -} collider. We observe a signal of 37{+-}8 events with a significance of 5.4 standard deviations including systematic uncertainties. The measured branching fraction is B(B{sup 0}{yields}{phi}K{sup 0}{gamma})=(2.74{+-}0.60{+-}0.32)x10{sup -6}, where the uncertainties are statistical and systematic, respectively. We also report the first measurements of time-dependent CP-violation parameters: S{sub {phi}}K{sub S}{sup 0}{sub {gamma}}=+0.74{sub -1.05}{sup +0.72}(stat){sub -0.24}{sup +0.10}(syst) and A{sub {phi}}K{sub S}{sup 0}{sub {gamma}}=+0.35{+-}0.58(stat){sub -0.10}{sup +0.23}(syst). Furthermore, we measure B(B{sup +}{yields}{phi}K{sup +}{gamma})=(2.48{+-}0.30{+-}0.24)x10{sup -6}, A{sub CP}=-0.03{+-}0.11{+-}0.08, and find that the signal is concentrated in the M{sub {phi}}K mass region near threshold.

• OSTI ID: 21607727
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 7 Vol. 84; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCELERATORS
ANTILEPTONS
ANTIMATTER
ANTIPARTICLES
ASYMMETRY
B MESONS
B NEUTRAL MESONS
BEAUTY MESONS
BEAUTY PARTICLES
BOSONS
BRANCHING RATIO
COLLISIONS
CP INVARIANCE
DECAY
DIMENSIONLESS NUMBERS
ELECTROMAGNETIC RADIATION
ELECTRON COLLISIONS
ELECTRON-POSITRON COLLISIONS
ELEMENTARY PARTICLES
FERMIONS
GAMMA DECAY
GAMMA RADIATION
HADRONS
INVARIANCE PRINCIPLES
IONIZING RADIATIONS
KAONS
KAONS NEUTRAL
KAONS PLUS
KEK LINAC
LEPTONS
LINEAR ACCELERATORS
MASS
MATTER
MESONS
NUCLEAR DECAY
PARTICLE DECAY
PHI MESONS
POSITRON COLLISIONS
POSITRONS
PSEUDOSCALAR MESONS
RADIATIONS
RADIATIVE DECAY
RESONANCE
STRANGE MESONS
STRANGE PARTICLES
TIME DEPENDENCE
VECTOR MESONS