Measurement of $B \to X \gamma$ Decays and Determination of $|V_{td}/V_{ts}

• Published in: Physical review letters 2009, Vol.102
• Main Authors: Aubert, B., Bona, M., Karyotakis, Y., Lees, J.P., Poireau, V., Prencipe, E., Prudent, X., Tisserand, V., Garra Tico, J., Grauges, E., Lopez, L., Palano, A., Pappagallo, M., Eigen, G., Stugu, B., Sun, L., Abrams, G.S., Battaglia, M., Brown, D.N., Cahn, R.N., Jacobsen, R.G., Kerth, L.T., Kolomensky, Yu. G., Lynch, G., Osipenkov, I.L., Ronan, M.T., Tackmann, K., Tanabe, T., Hawkes, C.M., Soni, N., Watson, A.T., Koch, H., Schroeder, T., Walker, D., Asgeirsson, D.J., Fulsom, B.G., Hearty, C., Mattison, T.S., Mckenna, J.A., Barrett, M., Khan, A., Blinov, V.E., Bukin, A.D., Buzykaev, A.R., Druzhinin, V.P., Golubev, V.B., Onuchin, A.P., Serednyakov, S.I., Skovpen, Yu. I., Solodov, E.P., Todyshev, K. Yu, Bondioli, M., Curry, S., Eschrich, I., Kirkby, D., Lankford, A.J., Lund, P., Mandelkern, M., Martin, E.C., Stoker, D.P., Abachi, S., Buchanan, C., Gary, J.W., Liu, F., Long, O., Shen, B.C., Vitug, G.M., Yasin, Z., Zhang, L., Sharma, V., Campagnari, C., Hong, T.M., Kovalskyi, D., Mazur, M.A., Richman, J.D., Beck, T.W., Eisner, A.M., Flacco, C.J., Heusch, C.A., Kroseberg, J., Lockman, W.S., Schalk, T., Schumm, B.A., Seiden, A., Wang, L., Wilson, M.G., Winstrom, L.O., Cheng, C.H., Doll, D.A., Echenard, B., Fang, F., Hitlin, D.G., Narsky, I., Piatenko, T., Porter, F.C., Andreassen, R., Mancinelli, G., Meadows, B.T., Mishra, K., Sokoloff, M.D.
• Format: Article
• Language: English
• Subjects: High Energy Physics - Experiment; Physics
• ISSN: 0031-9007; 1079-7114
• DOI: 10.1103/PhysRevLett.102.161803

Using a sample of 383 million $B\bar{B}$ events collected by the $BaBar$ experiment, we measure sums of seven exclusive final states $B\to X_{d(s)}\gamma$, where $X_d$($X_s$) is a non-strange (strange) charmless hadronic system in the mass range $0.6-1.8$ GeV$/c^2$. After correcting for unmeasured decay modes in this mass range, we obtain a branching fraction for $b \to d \gamma$ of $(7.2\pm 2.7(stat.)\pm 2.3(syst.))\times 10^{-6}$. Taking the ratio of $X_d$ to $X_s$ we find $\Gamma(b \to d \gamma)/\Gamma(b \to s \gamma) = 0.033 \pm 0.013 (stat.) \pm 0.009 (syst.),$ from which we determine $|V_{td}/V_{ts}|=0.177\pm 0.043$.