Study of pure annihilation type decays B to D_s} K.pdfVIP

BIHEP-TH-2003-13 ∗ Study of pure annihilation type decays B → D K s Ying Li∗ 3 0 Institute of High Energy Physics, CAS, P.O.Box 918(4), Beijing 100039, China; 0 2 Physics Department, NanJing Normal University, JiangSu 277600,China r p A and 0 Cai-Dian L¨u† 3 1 CCAST (World Laboratory), P.O. Box 8730, Beijing 100080, China; v 8 8 Institute of High Energy Physics, CAS, P.O.Box 918(4) Beijing 100039, China‡ 2 4 0 February 1, 2008 3 0 / h p - p e h : Abstract v i In this work, we calculate the rare decays B0 → D∗−K+ and B+ → D∗+K0 X s s r a in perturbative QCD approach with Sudakov resummation. We give the branching ratio of 10−5 for B0 → D∗−K+ , which will be tested soon in B factories. The decay s B+ → D∗+K0 has a very small branching ratio at O(10−8 ), due to the suppression s from CKM matrix elements |V ∗ Vcd |. It may be sensitive to new physics contributions. ub ∗e-mail: liying@mail.ihep.ac.cn †e-mail: lucd@ihep.ac.cn ‡Mailing address. 1 1 Introduction Perturbative QCD (PQCD) method for B decays has been developed for some years [1]. It is successfully applied to ex