%V 97 %O © 2006 The American Physical Society %D 2006 %X We present the first evidence of the decay B-->tau(-)nu(tau), using 414 fb(-1) of data collected at the Upsilon(4S) resonance with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. Events are tagged by fully reconstructing one of the B mesons in hadronic modes. We detect the signal with a significance of 3.5 standard deviations including systematics and measure the branching fraction to be B(B-->tau(-)nu(tau))=(1.79(-0.49)(+0.56)(stat)(-0.51)(+0.46)(syst))x10(-4). This implies that f(B)=0.229(-0.031)(+0.036)(stat)(-0.037)(+0.034)(syst) GeV and is the first direct measurement of this quantity. %K DETECTOR, PHYSICS %J PHYS REV LETT %A K Ikado %A K Abe %A K Abe %A I Adachi %A H Aihara %A K Akai %A M Akemoto %A D Anipko %A K Arinstein %A V Aulchenko %A T Aushev %A T Aziz %A AM Bakich %A V Balagura %A M Barbero %A A Bay %A I Bedny %A K Belous %A U Bitenc %A I Bizjak %A A Bondar %A A Bozek %A M Bracko %A TE Browder %A P Chang %A A Chen %A WT Chen %A Y Choi %A S Cole %A J Dalseno %A M Danilov %A M Dash %A S Eidelman %A D Epifanov %A J Flanagan %A S Fratina %A K Furukawa %A N Gabyshev %A T Gershon %A A Go %A G Gokhroo %A B Golob %A A Gorisek %A H Ha %A J Haba %A K Hara %A T Hara %A NC Hastings %A K Hayasaka %A H Hayashii %A M Hazumi %A L Hinz %A T Hokuue %A Y Hoshi %A S Hou %A WS Hou %A N Iida %A T Iijima %A A Imoto %A K Inami %A A Ishikawa %A H Ishino %A R Itoh %A M Iwasaki %A Y Iwasaki %A T Kamitani %A JH Kang %A SU Kataoka %A N Katayama %A H Kawai %A T Kawasaki %A H Kichimi %A E Kikutani %A HJ Kim %A HO Kim %A K Kinoshita %A H Koiso %A S Korpar %A P Krizan %A P Krokovny %A R Kulasiri %A R Kumar %A CC Kuo %A A Kuzmin %A YJ Kwon %A JS Lange %A G Leder %A J Lee %A T Lesiak %A A Limosani %A SW Lin %A D Liventsev %A D Marlow %A T Matsumoto %A A Matyja %A S McOnie %A S Michizono %A T Mimashi %A W Mitaroff %A K Miyabayashi %A H Miyata %A Y Miyazaki %A R Mizuk %A T Nagamine %A I Nakamura %A TT Nakamura %A E Nakano %A M Nakao %A S Nishida %A O Nitoh %A S Noguchi %A T Nozaki %A S Ogawa %A Y Ogawa %A K Ohmi %A T Ohshima %A N Ohuchi %A K Oide %A T Okabe %A S Okuno %A SL Olsen %A Y Onuki %A W Ostrowicz %A H Ozaki %A P Pakhlov %A CW Park %A H Park %A R Pestotnik %A LE Piilonen %A A Poluektov %A M Rozanska %A Y Sakai %A T Schietinger %A O Schneider %A C Schwanda %A K Senyo %A ME Sevior %A M Shapkin %A H Shibuya %A T Shidara %A B Shwartz %A V Sidorov %A A Sokolov %A A Somov %A S Stanic %A M Staric %A H Stoeck %A K Sumisawa %A T Sumiyoshi %A S Suzuki %A O Tajima %A F Takasaki %A K Tamai %A N Tamura %A M Tanaka %A M Tawada %A GN Taylor %A Y Teramoto %A XC Tian %A K Trabelsi %A T Tsuboyama %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 Y Watanabe %A E Won %A BD Yabsley %A A Yamaguchi %A Y Yamashita %A M Yamauchi %A M Yoshida %A Y Yusa %A LM Zhang %A ZP Zhang %A V Zhilich %A D Zurcher %A Belle Collaborat %T Evidence of the purely leptonic decay B- -> tau(-)(v)over-bar(tau) %N 25 %L discovery1308528 %I AMERICAN PHYSICAL SOC