University of Maryland An overview of BaBar physics & prospects Hassan Jawahery University of Maryland SLUO meeting of Sept 11. 2006

Outline A few comments on the status of the experiment. A brief overview of impact of BaBar physics & the physics harvest of summer 2006 Outlook for the 1/ab phase. The best and freshest results to be presented by Denis Dujmic later at this meeting and David Lange in his SLAC seminar on Wednesday.

The B factory: PEP II Machine & BaBar Detector Operating at the U(4s) resonance

The BABAR Collaboration USA [38/311] California Institute of Technology UC, Irvine UC, Los Angeles UC, Riverside UC, San Diego UC, Santa Barbara UC, Santa Cruz U of Cincinnati U of Colorado Colorado State Harvard U U of Iowa Iowa State U LBNL LLNL U of Louisville U of Maryland U of Massachusetts, Amherst MIT U of Mississippi Mount Holyoke College SUNY, Albany U of Notre Dame Ohio State U U of Oregon U of Pennsylvania Prairie View A&M U Princeton U SLAC U of South Carolina INFN, Perugia & Univ INFN, Roma & Univ "La Sapienza" INFN, Torino & Univ INFN, Trieste & Univ The Netherlands [1/4] NIKHEF, Amsterdam Norway [1/3] U of Bergen Russia [1/13] Budker Institute, Novosibirsk Spain [2/3] IFAE-Barcelona IFIC-Valencia United Kingdom [11/75] U of Birmingham U of Bristol Brunel U U of Edinburgh U of Liverpool Imperial College Queen Mary , U of London U of London, Royal Holloway U of Manchester Rutherford Appleton Laboratory U of Warwick The BABAR Collaboration 11 Countries 80 Institutions 623 Physicists Stanford U U of Tennessee U of Texas at Austin U of Texas at Dallas Vanderbilt U of Wisconsin Yale Canada [4/24] U of British Columbia McGill U U de Montréal U of Victoria China [1/5] Inst. of High Energy Physics, Beijing France [5/53] LAPP, Annecy LAL Orsay LPNHE des Universités Paris VI et VII Ecole Polytechnique, Laboratoire Leprince-Ringuet CEA, DAPNIA, CE-Saclay Germany [5/24] Ruhr U Bochum U Dortmund Technische U Dresden U Heidelberg U Rostock Italy [12/99] INFN, Bari INFN, Ferrara Lab. Nazionali di Frascati dell' INFN INFN, Genova & Univ INFN, Milano & Univ INFN, Napoli & Univ INFN, Padova & Univ INFN, Pisa & Univ & Scuola Normale Superiore

End of the eventful Run 5- August 21 PEP II Reached 12.0x 1033 /cm2 /s A heroic achievement. Congratulations to the PEP II team! BaBar collects ~96% of PEP II delivery

Partial composition of the data BaBar Data: Runs 1-5 Partial composition of the data

Onward to the 1/ab data phase 2006-2008 Shutdown Aug 21 through Dec. 06- PEP II Upgrade: Major upgrade to the machine to take the peak luminosity from 12x1033 /cm2/s  20 x1033 /cm2/s (list from John Seeman) BaBar: Completing the upgrade of the Instrumented Flux Return (IFR)- replace RPC’s with LST’s in the remaining 4 sectors (2 sectors were done in 2002). Expect to fully recover (the slowly deteriorating) muon and KL identification capabilities of the detector. Preparing for the expected higher data rate (and possibly higher background). Aims to stay at its usual very high efficiency of data collection (~96% historical average). Now studying the trigger and data flow system for possible bottlenecks and preparing for solutions. Now in the third week of the shutdown and on schedule.

Future PEP-II Overall Parameters and Goals A page from John Seeman Parameter Units Design Present best 2007 goal I+ mA 2140 2900 4000 I- 750 1875 2200 Number bunches 1658 1722 1732 by* mm 15-20 10 8-8.5 Bunch length 15 11-12 8.5-9 xy 0.03 0.05-0.07 0.06-0.075 Luminosity x1033 3 12.1 20 Int lumin in 24 hours pb-1 130 911 1300 4 times design 7 times design

Onward to the 1/ab Phase of BaBar 2006-2008 Another page from John Seeman Goal = 940 fb-1 2007 Down 2006 Down Now

The physics reach of the BaBar Data Just about any physics that is accessible at Charm Physics Tau physics Continuum e+e- hadrons ISR: e+e- hadrons from threshold to ~5 GeV CP Studies with B’s & B Physics

Physics Harvest of summer 2006 Runs 1-5     Submitted 114 papers to the ICHEP 2006 in Moscow http://www-public.slac.stanford.edu/babar/ICHEP06_papers_temp.htm    Measurements related to alpha (5 ) Measurements related to beta (14) Measurements related to gamma (8) Charmless B Decays (18) B decays to open Charm (12) Semileptonic B decays (10) Radiative Penguin and Leptonic B decays (10) Charmonium and Charm Spectroscopy (16) Production and decay of Charm and Charmonium states (13) Tau and low energy physics (8) & 26 Invited Talks [Some excerpts here]

The physics reach of the BaBar Data:charm Charm physics with Search for D0 mixing – highly suppressed in SM- a powerful window for NP searches The Latest from BaBar Observables: CP even state: width G1 , mass m1 ; CP odd state: width G2 , mass m2 y = (G1 - G2) / (G1 + G2) = DG / 2G x = (m1 – m2) / G = Dm / G D0 Mixing Still consistent with zero. Limits approaching the SM expectation

The physics reach of the BaBar Data: charm More Charm physics with Charm Spectroscopy: Keep finding New Charm Meson and Baryon states- Testing ground for Lattice QCD: Measurements of decay constants fD, fDs, fD/ fDs & Form Factors are now emerging = By validating LQCD, we may hope for better knowledge of fB & (BB?) , hence better knowledge of |Vub|, |Vtd|, |Vts| & |Vtd|/ Vts| Many engineering results of importance to B decays: e.g. measuring the phase and amplitude across several 3-body D meson Dalitz plots is critical for measuring angles g & b with B decays. Our latest: Observation of a new excited charm baryon Wc* ® Wc0 g Wait for David Lange’s seminar for details Wc* ® Wc0 g FDs=248+/-15+/-6+/-31 MeV

The physics reach of the BaBar data: t decays B factory data the primary source for searches for Lepton Flavor Violation (LFV) in t decays: Recent results on: tmg & teg - tmh & (Lepton and Flavor Violating decays) tLh highly suppressed in SM; (see David Lange’s talk for new BaBar results) From Roger Barlow’s talk at ICHEP06 Example of how it impacts Limits on Branching ratios: @90% C.L BaBar: Br(tmg)<0.68x10-7 Br(teg)<1.1x10-7 Belle: Br(tmg)<0.41x10-7 Br(teg)<1.2x10-7 Belle result BaBar result Excluded region

The physics reach of the BaBa: ISR Hadron Provides access to e+e- from threshold to ~5 GeV Allows for determination of R, which goes into calculation of muon g-2. So far has Measured: .e+e ® pp, p+p-p-, 2p+2p-, K+K-p+p-, 2K+2K-, 3p+3p-, 2p+2p-p0p0, K+K-2p+2p-, K+Kp+p-, K+Kppf0 Discovery of New States- Y(4260), and further investigation of new states Showing new structure (2S) N=125±23 (>8 σ) This year’s new structure

The physics reach of the BaBar Data: B Decays B Physics [with the ] Investigation of CP violation in B meson Decays & tests of the CKM paradigm Is the CP symmetry broken in B decays? Can we fit the CPV effects in the CKM picture? Is there room for New Physics? Search for New Physics in rare (SM suppressed-FCNC) decays ? B Decays dynamics: Tests of QCD predictions

A brief history of major milestones in B physics The 1/ab phase: Precision tests of the CKM paradigm- Search for N.P. using loop dominated B decays, LFV tau decays, DD(bar) mixing … 109-- Precision sin2b; a & g measured; CKM over-constrained and established as the primary source of observed CPV in nature. Data consistent with no NP effects in b-d and sd. 108-- 2001- CPV in B decays observed. Sin2b consistent with SM 107-- #B’s 1999- B Factories start operation. 1993-Radiative penguin bsg observed; Major constraint on models of New Physics;Rare decays BKp and pp obserevd; Role of gluonic penguins established; B factory projects launched. 106-- 105-- 1987-B0 mixing & Vub measured; Lower bound on m(top)>42 GeV; with non-zero Vub, CKM in the game as a source of CPV 104-- 1981-B meson observed

The Latest on the CKM test: Theorist view of CKM Observables The view from the experiments a g Picture from A. Hoecker

Check for New Physics contribution From J. Charles @ FPCP 2006 Vancouver, Ca Check for New Physics contribution Back

Any room for New Physics contributions? The analysis by the UTfit collab. allows NP amplitude and phase: [ Hep-ph/0509219] SM solution CBd=1 & fBd=0 Non –SM solution is now essentially excluded. Limits on Semileptonic asymmetry (Asl) from BaBar & D0

New sources of CP violation in bd & sd are strongly constrained. The message from New Physics Fits to CKM observables (As presented at LP2005- by L. Silvestrini) – New sources of CP violation in bd & sd are strongly constrained. New Physics contributions to the bs transitions are much less constrained & are in fact well motivated by models explaining large mixing angles in neutrino sector- bR tL bL W sL L Possible New Physics presence can alter the observables from SM expecations

fcp f The “sin2bpenguin” Test: Mixing induced CP violation in penguin modes b->sqq B0 fcp B0 For fcp =from b->sqq Within the SM: Dominant amplitude (~l2)- same phase as b->ccs f suppressed amplitude (~l4) Expect within SM Sf~ -hcpsin2b With new physics and new phases, Sf could depart from -hcpsin2b The Task: Measure DSf=-hcpSf – sin2b & search for deviation from zero A Key Question: How well do we know DSf within the SM?

~ 2.5 s deviation at this point. Expected DS with SM More details in Denis Dujmic’s talk Simple average: Spenguins=0.52 +/- 0.05 vs reference point: sin2b=0.68+/-0.03 ~ 2.5 s deviation at this point. Eagerly waiting for more data

bsg- & bsl+l- - well established venues for NP searches bR tL bL W sL L Measured rates consistent with SM: BF(b→sg)TH = 3.57 ± 0.30 x 10-4 (SM NLO) BF(b→sg)EXP = 3.55 ± 0.26 x 10-4 (HFAG) D0 But there is more handles in these channels Photon polarization in bgsL (g left-handed in SM) Direct CP violation – nearly zero in SM In BKll- q2 dependence of the rate; FB asymmetry, polariztion Search for NP modification of Wilson coefficients C7, C9, C10 b-d g is now also established by BaBar & Belle BaBar’s limit on Bpll

Tests with bsl+l- [BK*l+l- ] Probe deviation of wilson coefficients., C7, C9, C10 from SM FT = 1 – F0 Zero point of AFB a probe of NP influence K* pol. FL C7 = -C7(SM) Wrong sign C9C10 excluded Cannot exclude opposite sign C7 yet C9C10 = -C9C10(SM)

+ Tests with Direct CP violations Direct CP violation results when several diagrams, with different cp conserving and cp breaking phases contributing to the same final state, interfere: BKp: (K+ p- , K0 p+ , K0 p0 , ..) E.g. BKp: + A contributing diagram from “New Physics” can alter Acp from the SM values. But need predictions of Acp within SM- Again rely on QCDF or PQCD, or exploit symmetries (SU2, SU3 etc) to connect Acp in different modes and derive sum rules- to be tested.

Acp(B0K+p-)= -0.099+/- 0.016 Kp puzzle Within SM: Expect Acp(b->sg) ~ 0 Another potential source of tension with SM Acp(B0K+p-)= -0.099+/- 0.016 Kp puzzle superweak is really out; to use as NP observable need reliable QCD predictions; Ample data to test & calibrate the calculations on.

Prospects for the CKM observables in the “1/ab” phase (~ +1/ab from Belle) Now ~7% ~30O ~11o ~0.04 Aiming for: Also counting on improved systematics in most areas & help from the theory side & s(Vtd/Vts)<4% (mostly from Tevatron).

Summary comments There is an enormous amount of physics still to come from Flavor physics with BaBar in its “1/ab” phase. Two of the expected major outcomes are: Precision knowledge of the charge weak sector of the SM & CKM parameters, With the possibility of revealing deviation from the SM Measurements of CP violation and decay properties in penguin dominated decay modes, with the possibility of revealing New Physics effects. Hints are already present in the current data. [Given the large number of observables involved, a pattern may emerge showing evidence for New Physics. If we continue to see no deviation at these precisions- the results will likely serve as major constraints on the flavor structure of New Physics- to be seen at LHC.] PEP II and BaBar are in preparation for the “1/ab” phase. Both upgrade efforts are proceeding well and on schedule.

Back up Slides On Prospects for CKM Observables

Measuring Vub= |Vub|e-ig Higher precision on knowledge of Vub is absolutely essential- one of the main sources of tension in CKM tests sin2 =0.791±0.034 from indirect determination sin2=0.687±0.032 From direct measurement

Must resolve exclusive & inclusive discrepancy Inclusive channels Exclusive channels ~7% measurement now Aiming for 5% accuracy Must resolve exclusive & inclusive discrepancy

Measuring g: Vub= |Vub|e-ig Decays involving interference of tree level bu & bc Processes. + B-  (Df)K- F=common to D0 & anti D0 Solve for g, & d=(,d1-d2) – rB=(|A1|/ |A2|) f=DCP (Gronau-London-Wyler)(GLW method) (small asymmetry) f=DCSD (Atwood-Duniets-Soni)(ADS Method) (additional problem of dD) f= Dalitz analysis of D0->Ksp+p- (GGSZ) (combines features of GLW & ADS depending on the location in Dalitz plot)- the dominant method [Giri, Grossman, Soffer, & Zupan, PRD 68, 054018 (2003), Bondar (Belle), PRD 70, 072003 (2004)]

Measuring g: Vub= |Vub|e-ig The method highly sensitive to rB: fits favor rB ~ 0.1 (BaBar) ; rB >0.2 (Belle). Main cause of the difference in errors From the Dalitz Analysis alone: g=(92+/- 41  11 +/- 12 )o (BaBar) φ3=53° +15-18  3° 9°) Belle Combined (UTfit): g = 78 +/- 30o All methods Error due to uncertainties in treatment of the DKspp-Dalitz plot (amplitudes and phases) CLEO-c data can help. Projected error 3-5 deg (@1/ab Future of g rB=0.1 2008: 5-10o Requires improvement in D-Dalitz model – from CLEO-c data and higher statistics tagged D* events at B factories

Measuring a: The prescription Bp p: (p+ p-, p+ p0, p0 p0 ) Brp, B r r, ….. With Tree alone But penguins (gluonic & E.W) can also lead to the same decays: B->p0p0 sets the scale of the Da correction Da Estimate Da by constructing the isospin triangle(Gronau & London)

Measuring a B(p+p0) = (5.75 0.42) B(p+p-) = (5.20 0.25)  10-6 A(p0p0) = +0.35 0.33 S(p+p-) = -0.59  0.09 A(p+p-) = +0.39  0.07 Br(Br+r-)=23.5+/- 2.2+/- 4.1x10-6 Br(Br+r0)=16.8+/- 2.2+/- 2.3x10-6 Br(Br0r0)=1.16+/- 0.37+/- 0.27x10-6 S=-0.19 +/- 0.21 +0.05-0.07 C=-0.07 +/- 0.15+/- 0.06 Longitudenal polarization fraction dominate (~90%) A=-C Good news for a: A very lucky angle! Longitudinal polarization dominates-CP even & small B->r0r0 compared to B->r+r0 , B->r+r-  suppressed penguin contributions-

Other ways of estimating penguin effects Measuring a BaBar: at 68% c.l. (Brr, pp, rp) (WA) Already the error is systematic (theory) dominated. At ~2/ab, expect s(a) ~ 7o - 10o depending on the size of B->r0r0 . Measuring B->r0r0 & its Time-dependent CP asymmetry will shrink errors further. Other ways of estimating penguin effects

Measuring sin2b: Sin2b is a precision measurement now - the non-SM solution is essentially excluded B->J/yK* & B->D0h No evidence for direct CP violation- consistent with dominance of one diagram only- At 2/ab (together with Belle): Expect another factor of 2 reduction of errors