Input From Breco AWG

1. Input From Breco AWG • Most suggestions are to: • Modify rate for various Br. Ratio based on CLEO/BELLE/BABAR numbers • Introduce new decay mode (s) • 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) • http://babar-hn.slac.stanford.edu:5090/HyperNews/get/EHBDOC/402.html

2. Hadronic Color Suppressed Modes : B -> D(*) 0 p0 ,,, • CLEO/Belle/Babar [2001-02] see a surprising larger rate than suggested by a universal |a1| & |a2| 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) • http://babar-hn.slac.stanford.edu:5090/HyperNews/get/EHBDOC/402/2.html Vcb b c D(*)0 u p0 ,,, d q

3. B0 -> Ds(*)+ p- c • 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 & proposalhttp://babar.roma1.infn.it/~voena/ceciliagen.html • Backgrounds to this study come fromcharmless 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 DS(*)- s b u Vub p, ,a1 q q

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 g 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 • http://babar-hn.slac.stanford.edu:5090/HyperNews/get/EHBDOC/402/4.html • And from Tanya McMahon for B -> D*K* (various configurations) • http://babar-hn.slac.stanford.edu:5090/HyperNews/get/EHBDOC/402/3.html • 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(*) : “Sin2b” • 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: • http://babar-hn.slac.stanford.edu:5090/HyperNews/get/EHBDOC/402/1.html • 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 0.0141, 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) = (10.4 +3.5 -3.0 (stat) +- 1.9 (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 g 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.80:1150-55 (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