WG3 Session 3 
March 18, 8:30am10:00am (Santa Barbara)  V_{td} and V_{ts} chair:J.Berryhill 


Rare radiative & semileptonic B decays  
8:308:45 (Exp)  B → ργ, B → K^{*}γ, prospects for B → X_{d}γ  Shohei Nishida  
8:559:10 (Th)  (b → dγ)/(b → sγ) (exclusive and inclusive) 
Stefan Bosch  
9:209:30 (Exp)  b → sl^{+}l^{} and prospects for b → dl^{+}l^{}  Jonathan Hollar  
9:409:50 (Th)  (b → dl^{+}l^{})/(b → sl^{+}l^{}) (exclusive and inclusive) 
Thorsten Feldmann 
Rare radiative & semileptonic B decays:
 The CKM constraints from (B → ργ)/(B → K^{*}γ):
 Can they be competitive with the "canonical" ones?
 How does the V_{td}/V_{ts} precision compare with B_{d}/B_{s} mixing ratio?
 How does the projected experimental precision of BaBar+Belle compare with CDF+D0?
 Longdistance contributions to B → ργ and B → K^{*}γ:
 Which calculations can really be trusted?
 How can the theoretical precision on the form factor ratio or the weak annihilation contribution be improved?
 The b → d gamma decays:
 Is a sumofexclusive states (or otherwise inclusive) B → X_{d}γ measurement possible in the B factory era?
 For B → X_{d}γ and B → ργ, what is the tradeoff between signal statistics and continuum background level for selectively tagging the recoil B?
 The b → (s,d)l^{+}l^{} decays:
 Do these processes have a unique added value in constraining CKM physics, compared to b → (s,d)γ? Or do they matter for new physics search only?
 Is any b → dl^{+}l^{} penguin decay observation possible in the Bfactory era?
 What are the prospects beyond that era?
 Are there other interesting ratios of rates involving penguin decays which constrain the CKM matrix in a useful way (such as ratios with b → u semileptonic decays)?
 See also the charges for the joint session with WG2, in particular:
 What is the experimental and theoretical status of inclusive B → X_{s}γ?
 Where does theory enter in the measurements of heavy → light transitions? Where does it need to be improved?