%O © 2007 The American Physical Society %D 2007 %V 98 %N 18 %I AMERICAN PHYSICAL SOC %L discovery1308545 %X Using 449x10(6) B(B) over bar pairs collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider, we observe clear signals for B+->(K) over bar K-0(+) and B-0 ->(K) over bar K-0(0) decays with 5.3 sigma and 6.0 sigma significance, respectively. We measure the branching fractions B(B+->(K) over bar K-0(+))=(1.22(-0.28-0.16)(+0.32+0.13))x10(-6) and B(B-0 ->(K) over bar K-0(0))=(0.87(-0.20)(+0.25)+/- 0.09)x10(-6), and partial-rate asymmetries A(CP)(B+->(K) over bar K-0(+))=0.13(-0.24)(+0.23)+/- 0.02 and A(CP)(B-0 ->(K) over bar K-0(0))=-0.58(-0.66)(+0.73)+/- 0.04. From a simultaneous fit, we also obtain B(B+-> K-0 pi(+))=(22.8(-0.7)(+0.8)+/- 1.3)x10(-6) and A(CP)(B+-> K-0 pi(+))=0.03 +/- 0.03 +/- 0.01. The first and second error in the branching fractions and the partial-rate asymmetries are statistical and systematic, respectively. No signal is observed for B-0 -> K+K- decays, and for this branching fraction, we set an upper limit of 4.1x10(-7) at the 90% confidence level. %K INDUCED CP VIOLATION, BELLE, DETECTOR %J PHYS REV LETT %A SW Lin %A P Chang %A K Abe %A K Abe %A I Adachi %A H Aihara %A D Anipko %A K Arinstein %A V Aulchenko %A T Aushev %A T Aziz %A AM Bakich %A E Barberio %A A Bay %A I Bedny %A K Belous %A U Bitenc %A I Bizjak %A S Blyth %A A Bondar %A A Bozek %A M Bracko %A Y Chao %A A Chen %A KF Chen %A WT Chen %A BG Cheon %A R Chistov %A SK Choi %A Y Choi %A YK Choi %A J Dalseno %A M Dash %A J Dragic %A S Eidelman %A S Fratina %A N Gabyshev %A T Gershon %A A Go %A G Gokhroo %A B Golob %A H Ha %A J Haba %A T Hara %A K Hayasaka %A H Hayashii %A M Hazumi %A D Heffernan %A Y Hoshi %A S Hou %A WS Hou %A YB Hsiung %A T Iijima %A K Ikado %A A Imoto %A K Inami %A A Ishikawa %A H Ishino %A R Itoh %A M Iwasaki %A Y Iwasaki %A H Kaji %A JH Kang %A N Katayama %A H Kawai %A T Kawasaki %A HR Khan %A H Kichimi %A YJ Kim %A K Kinoshita %A S Korpar %A P Krizan %A R Kulasiri %A CC Kuo %A YJ Kwon %A JS Lange %A J Lee %A MJ Lee %A SE Lee %A T Lesiak %A A Limosani %A F Mandl %A T Matsumoto %A S McOnie %A W Mitaroff %A K Miabayashi %A H Miyaki %A H Miyata %A Y Miyazaki %A R Mizuk %A D Mohapatra %A T Mori %A I Nakamura %A E Nakano %A M Nakao %A S Nishida %A O Nitoh %A S Noguchi %A T Nozaki %A S Ogawa %A T Ohshima %A S Okuno %A SL Olsen %A Y Onuki %A H Ozaki %A P Pakhlov %A G Pakhlova %A CW Park %A H Park %A KS Park %A R Pestotnik %A LE Piilonen %A H Sahoo %A Y Sakai %A N Satoyama %A T Schietinger %A O Schneider %A J Schumann %A AJ Schwartz %A K Senyo %A M Shapkin %A JB Singh %A A Sokolov %A A Somov %A N Soni %A S Stanic %A M Staric %A H Stoeck %A T Sumiyoshi %A O Tajima %A F Takasaki %A K Tamai %A N Tamura %A M Tanaka %A GN Taylor %A Y Teramoto %A XC Tian %A I Tikhomirov %A K Trabelsi %A T Tsukamoto %A S Uehara %A T Uglov %A K Ueno %A Y Unno %A S Uno %A Y Usov %A G Varner %A S Villa %A CC Wang %A CH Wang %A MZ Wang %A Y Watanabe %A E Won %A QL Xie %A BD Yabsley %A A Yamaguchi %A Y Yamashita %A M Yamauchi %A CC Zhang %A LM Zhang %A ZP Zhang %A V Zhilich %A A Zupanc %T Observation of B decays to two kaons