skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

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

Abstract

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.

Authors:
; ; ; ;  [1]; ; ; ; ; ; ; ; ; ; ; ; ;  [2]; ;  [3]
  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)
Publication Date:
OSTI Identifier:
21607727
Resource Type:
Journal Article
Journal Name:
Physical Review. D, Particles Fields
Additional Journal Information:
Journal Volume: 84; Journal Issue: 7; Other Information: DOI: 10.1103/PhysRevD.84.071101; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0556-2821
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; B NEUTRAL MESONS; BRANCHING RATIO; CP INVARIANCE; ELECTRON-POSITRON COLLISIONS; GAMMA DECAY; GAMMA RADIATION; KAONS NEUTRAL; KAONS PLUS; KEK LINAC; MASS; PHI MESONS; POSITRONS; RADIATIVE DECAY; RESONANCE; TIME DEPENDENCE; VECTOR MESONS; ACCELERATORS; ANTILEPTONS; ANTIMATTER; ANTIPARTICLES; B MESONS; BEAUTY MESONS; BEAUTY PARTICLES; BOSONS; COLLISIONS; DECAY; DIMENSIONLESS NUMBERS; ELECTROMAGNETIC RADIATION; ELECTRON COLLISIONS; ELEMENTARY PARTICLES; FERMIONS; HADRONS; INVARIANCE PRINCIPLES; IONIZING RADIATIONS; KAONS; LEPTONS; LINEAR ACCELERATORS; MATTER; MESONS; NUCLEAR DECAY; PARTICLE DECAY; POSITRON COLLISIONS; PSEUDOSCALAR MESONS; RADIATIONS; STRANGE MESONS; STRANGE PARTICLES

Citation Formats

Sahoo, H., Browder, T. E., Nishimura, K., Vahsen, S. E., Varner, G., 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., Asner, D. M., and Fast, J. E. First observation of radiative B{sup 0}{yields}{phi}K{sup 0}{gamma} decays and measurements of their time-dependent CP violation. United States: N. p., 2011. Web. doi:10.1103/PHYSREVD.84.071101.
Sahoo, H., Browder, T. E., Nishimura, K., Vahsen, S. E., Varner, G., 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., Asner, D. M., & Fast, J. E. First observation of radiative B{sup 0}{yields}{phi}K{sup 0}{gamma} decays and measurements of their time-dependent CP violation. United States. doi:10.1103/PHYSREVD.84.071101.
Sahoo, H., Browder, T. E., Nishimura, K., Vahsen, S. E., Varner, G., 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., Asner, D. M., and Fast, J. E. Sat . "First observation of radiative B{sup 0}{yields}{phi}K{sup 0}{gamma} decays and measurements of their time-dependent CP violation". United States. doi:10.1103/PHYSREVD.84.071101.
@article{osti_21607727,
title = {First observation of radiative B{sup 0}{yields}{phi}K{sup 0}{gamma} decays and measurements of their time-dependent CP violation},
author = {Sahoo, H. and Browder, T. E. and Nishimura, K. and Vahsen, S. E. and Varner, G. and Adachi, I. and Haba, J. and Itoh, R. and Iwasaki, Y. and Nakao, M. and Nishida, S. and Nozaki, T. and Sakai, K. and Sakai, Y. and Sumisawa, K. and Trabelsi, K. and Uno, S. and Ushiroda, Y. and Asner, D. M. and Fast, J. E.},
abstractNote = {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.},
doi = {10.1103/PHYSREVD.84.071101},
journal = {Physical Review. D, Particles Fields},
issn = {0556-2821},
number = 7,
volume = 84,
place = {United States},
year = {2011},
month = {10}
}