1 Input From Breco AWG Most suggestions are to: 1.Modify rate for various Br. Ratio based on CLEO/BELLE/BABAR numbers 2.Introduce new decay mode (s) 3.Input on inclusive rates and spectra (prelim) –Survey not complete, will tell you what is not yet ready and hope to finalize rates in next weeks Need “Xtreme” Filtering Capability, should improve from what’s available currently –Motivation : make up for the poor ratio of Generic MC/data (belle does ~ 3/1) E.g B0 -> Ds pi, B -> D*D, B ->DK analysis (we had to sweat for Winter conferences) –Must have seamless capability for inserting “ event generator 4-vector level” user code to do filtering out relevant class of “pathological” events for say “peaking background” studies (see Abi’s talk which seems like a step in the right direction) This issue becomes more and more relevant as data sizes increase (and MC/DATA size wont quadruple …unfortunately) In this talk, rather than give a complete list of all feedback, will give a brief summary and point to the Breco HN thread where all feedback has been posted (and more will come soon) –

2 Hadronic Color Suppressed Modes : B -> D (*) 0    CLEO/Belle/Babar [ ] see a surprising larger rate than suggested by a universal |a 1 | & |a 2 | coeff. derived from, e.g., B0 -> D+pi- and B0 -> psi Ks Rates in BaBar MC follow old CLEO PRD (~1998) …must improve See proposal from Adlene Hicheur based on CLEO/BELLE results (on behalf of ColSup analysts) – b q c u d D (*)0    V cb

3 B 0 -> Ds (*)+   B0 -> Ds pi observed by Babar [2002], Ds*pi/rho/a1 etc must also exist but with unpredictable rate (QCD factorization ansatz does not work here). Babar MC does not have this decay. Suggest introduce such decays (with similar rates for each mode (~ [ 3-8] *10-5 ). See Cecilia Voena’s study of BaBar MC & proposal Backgrounds to this study come from charmless 3-4 body decays like –B0->Kkpipi (resonant & Non-resonant) –B0->Kpipipi etc –Suggest updating these numbers (see same HN posting) with concurrence of the 3- 4 body charmless AWG b q q V ub c s u D S (*)-   ,  a 1

4 B -> Ds(*) K(*) : Important mode to understand source of B -> Ds pi Not observed, must happen either due to W-exchange or FSI at some level Babar sees a possible (but statistically limited “signal”) –Hints at a strength comparable to B -> Ds pi –Suggestion from Cecilia et al to turn it on at level similar to Dspi How does EvtGen handle W-exchange/FSI …anything clever? –Background from 3-4 body charmless decays

5 B –> D(*) K(*) Modes valuable for CKM angle  studies, check QCD dynamics Proposal from Matteo Rama on various signal and pathological background ( B -> K h+ h-) rates and comparison with Babar MC/PDG2000 – And from Tanya McMahon for B -> D*K* (various configurations) – Bottomline : –substantial differences between Babar Decay.dec vs recent measurements for B _> D(*) K(*) –Note on CP = -1 D modes, check if some of the modes ( Ks eta, Ks Omega) have been measured and have common mechanism + what is in Decay.dec ??

6 B -> D* D(*) : “Sin2  ” Change rates for these processes as per BaBar observations …marginal change ? Don’t modify weights of (the three) decay amplitudes in B -> D*D* See note and recommendations by Gloria Vuagnin: – –She writes “Studying the background for D*D* we also noticed that two dangerous modes are not well modelled by the DECAY.DEC. These modes are: Ds*D* and D*0D*. The former has a BR set to , about 25% lower than the unpublished results from BaBar. The latter is not present in the DECAY.DEC. An unpublished result, based on Run1 data and described in BAD 252, gives the value: BR(B+- ->D*D*0) = ( (stat) (syst)) x10-4 “ B -> D* D+ input ??..Justin

7 B -> D (*) D (*) K: From P. Robbe’s Thesis Expect modifications to Decay.dec but wait for final word from Patrick Robbe (currently enjoying a post-PhD defense vacation

8 B + -> D0 K+ pi0 This transparency is to remind us that we need input on what is (not) in Babar MC Troels Peterson, Soffer, Aleksan hope to learn about  from this mode, work just begining

9 D Meson Production in B Decays: Important for B Flavor Tagging Published work by CLEO utilizing recoiling high momentum lepton –Phys. Rev. Lett.80: (1998) –Unpublished result from Stephane, Sophie, Marie-Helene, Amina, Robert on Right and wrong sign D production in charged and neutral B meson decay Rate & D meson momentum spectra –See BAD note 236 V16 (B0 -> D, Dbar X) –See BAD note 407V5 (B- -> D, Dbar X) … B0 numbers not updated per BAD236 –See BAD note 281 V3 ( Charged Kaon multiplicity in B Decays) These numbers are preliminary but probably better than what is in EvtGen ?? Right sign D0 Wrong sign

10 Feedback to come Not a “finished” list : –Not all analysis subgroups have responded…pl. check Breco HN thread on this topic –Have not made a “future” analysis list of >100 fb-1 data B –> ”D**” npi B -> D(*) n pi & other unpublished semiexcl Breco “observations” of resonant substructure in D(*)X B -> Ds D (X) (IHBD??) B -> D*D*K (Ds**D??..Robbe Thesis) Baryon production in Hadronic B decays Implementation of CP asymmetry in B –> D(*)pi/Rho or DK?? What is the timescale for the new and improved Decay.dec ?? Must try to motivate more analysts to join the generator improvement effort –This is their interest