11/17/2003 AN   D** in data


Narrow D** resonances D_1(2420) and D^*_2(2460) can be observed in channels D*+ pi- and D0 pi-.

EvtGen event generator  predicts :

[Br(B0 => D_10(2420) mu) x Br( D_1(2420) => D*+pi-)] / [Br(B0 => D_2*0(2460) mu) x Br( D_2*0(2460) => D*+pi-)]  =  [0.0056 * 0.67] / [0.0037 * 0.209] = 4.8

thus  D*+ pi - will have contribution from mostly D_1(2420)

channel D0 pi+ will have a contribution from only D_2*+(2460)

[Br(B0 => D_2*+(2460) mu) x Br( D_2*+(2460) => D*+pi-)] / [Br(B0 => D_10(2420) mu) x Br( D_1(2420) => D*+pi-)]  = [0.0037 * 0.46] / [0.0056 * 0.67]  = 0.45

so we expect to find less D0pi from D_2*+(2460) than D*pi from D_1(2420) by factor of 1/0.45=2.2

12/26/2003 AN   check this D** peak out

 

Selections:

• muon
• Pt > 2.5 GeV
• nseg > 0
• right charge correlation with D*
  
• D0 
• K, pi > 0.7 GeV
  
• IP significance for K, pi > 3
• significance of D0 XY decay length wrt PV > 3
• mass window : [1.75 GeV - 1.95 GeV]
• Kaon has right charge correlation with muon
  
• D* 
• slow pion has right charge correlation with K
• mass window [0.142 GeV - 0.149 GeV]
• pion from D** 
• Pt > 0.5 GeV
• right charge correlation with D* (wrong charge correlation gives no signal - see histogram)
  
• B vertex (muon & D**)
  
• chi^2 < 9
• significance of B XY decay length wrt PV > 3