1# An overview of BaBar physics & prospects Hassan Jawahery University of Maryland SLUO meeting of Sept

2# 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.

3# The B factory: PEP II Machine & BaBar Detector Operating at the  s) resonance

4# 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 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 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 The BABAR Collaboration 11 Countries 80 Institutions 623 Physicists 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

5# End of the eventful Run 5- August 21 PEP II Reached 12.0x /cm 2 /s A heroic achievement. Congratulations to the PEP II team! BaBar collects ~96% of PEP II delivery

6#

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

8# Shutdown Aug 21 through Dec. 06-  PEP II Upgrade: Major upgrade to the machine to take the peak luminosity from 12x10 33 /cm 2 /s  20 x10 33 /cm 2 /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 K L 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. Onward to the 1/ab data phase Now in the third week of the shutdown and on schedule.

9# Future PEP-II Overall Parameters and Goals A page from John Seeman ParameterUnitsDesignPresent best 2007 goal I+mA I-mA Number bunches y*y* mm Bunch length mm yy Luminosityx Int lumin in 24 hours pb times design4 times design

10# 2007 Down 2006 Down Now Goal = 940 fb -1 Onward to the 1/ab Phase of BaBar Another page from John Seeman

11# 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

12# Physics Harvest of summer 2006 Runs 1-5 Submitted 114 papers to the ICHEP 2006 in Moscow 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]

13# Charm physics with  Search for D0 mixing – highly suppressed in SM- a powerful window for NP searches The physics reach of the BaBar Data:charm Observables: CP even state: width  , mass  m 1 ; CP odd state: width  , mass  m 2 y =    -        x = (m 1 – m 2 ) /  =  m /  The Latest from BaBar D 0 Mixing Still consistent with zero. Limits approaching the SM expectation

14# More Charm physics with  Charm Spectroscopy: Keep finding New Charm Meson and Baryon states-  Testing ground for Lattice QCD: Measurements of decay constants f D, f Ds, f D / f Ds & Form Factors are now emerging =  By validating LQCD, we may hope for better knowledge of f B & (B B ?), hence better knowledge of |V ub |, |V td |, |V ts | & |V td |/ V ts |  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  with B decays. The physics reach of the BaBar Data: charm Our latest: Observation of a new excited charm baryon  c *  c 0  Wait for David Lange’s seminar for details  c *  c 0  F Ds =248+/-15+/-6+/- 31 MeV

15#  B factory data the primary source for searches for Lepton Flavor Violation (LFV) in  decays: Recent results on:     e    Lepton and Flavor Violating decays)    h highly suppressed in SM; (see David Lange’s talk for new BaBar results) Limits on Branching C.L BaBar: Br(    x10 -7 Br(   e  x10 -7 Belle: Br(    x10 -7 Br(   e  x10 -7 The physics reach of the BaBar data:  decays Example of how it impacts From Roger Barlow’s talk at ICHEP06

16# 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,        2   2    K + K -      2K + 2K-, 3   3    2   2        K + K - 2   2    K + K       K + K       f 0  Discovery of New States- Y(4260), and further investigation of new states  (2S) N=125±23 (>8 σ) The physics reach of the BaBa: ISR Showing new structure This year’s new structure Hadron

17#  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 The physics reach of the BaBar Data: B Decays

18# B meson observed 1987-B 0 mixing & V ub measured; Lower bound on m(top)>42 GeV; with non-zero V ub, CKM in the game as a source of CPV 1993-Radiative penguin b  s  observed; Major constraint on models of New Physics;Rare decays B  K  and  obserevd; Role of gluonic penguins established; B factory projects launched B Factories start operation CPV in B decays observed. Sin2  consistent with SM 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 … Precision sin2  ;  &  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 # B’s A brief history of major milestones in B physics

19# The Latest on the CKM test: Picture from A. Hoecker Theorist view of CKM Observables The view from the experiments  

20# From J. FPCP 2006 Vancouver, Ca Check for New Physics contribution Back

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

22#  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- bRbR tLtL bLbL W sLsL LL Possible New Physics presence can alter the observables from SM expecations

23# B0B0 B0B0 f Within the SM: The “sin2  penguin ” Test: Mixing induced CP violation in penguin modes b->sqq f cp S f ~ -  cp sin2  Dominant amplitude (~   same phase as b->ccs suppressed amplitude (~   Expect within SM With new physics and new phases, S f could depart from -  cp sin2  The Task: Measure  S f =-  cp S f – sin2  search for deviation from zero A Key Question: How well do we know  S f within the SM? For f cp =from b->sqq

24# Simple average: S penguins =0.52 +/ vs reference point: sin  68+/-0.03 ~ 2.5  deviation at this point. Expected  S with SM Eagerly waiting for more data More details in Denis Dujmic’s talk

25# b  s  b  sl + l -  well established venues for NP searches Measured rates consistent with SM: BF(b → s  ) TH = 3.57 ± 0.30 x (SM NLO) BF(b → s  ) EXP = 3.55 ± 0.26 x (HFAG) bRbR tLtL bLbL W sLsL LL But there is more handles in these channels Photon polarization in b   s L (  left-handed in SM) Direct CP violation – nearly zero in SM In B  Kll- q 2 dependence of the rate; FB asymmetry, polariztion Search for NP modification of Wilson coefficients C7, C9, C10 D0 b-  d  is now also established by BaBar & Belle BaBar’s limit on B   ll

26# Tests with b  sl + l - [ B  K * l + l - ] F T = 1 – F 0 K* pol. F L C9C10 = -C9C10(SM) C7 = -C7(SM) Probe deviation of wilson coefficients., C7, C9, C10 from SM Wrong sign C9C10 excluded Cannot exclude opposite sign C7 yet Zero point of A FB a probe of NP influence

27# 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: + E.g. B  K  :                 ..  A contributing diagram from “New Physics” can alter A cp from the SM values. But need predictions of A cp within SM- Again rely on QCDF or PQCD, or exploit symmetries (SU2, SU3 etc) to connect A cp in different modes and derive sum rules- to be tested.

28# A cp (B 0  K     / Within SM: Expect A cp  b->s     superweak is really out; to use as NP observable need reliable QCD predictions; Ample data to test & calibrate the calculations on. Another potential source of tension with SM  puzzle

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

30# 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.

31# Back up Slides On Prospects for CKM Observables

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

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

34# Measuring  V ub = |V ub |e -i  + B -  (D  f)K- F=common to D0 & anti D0 Decays involving interference of tree level b  u & b  c Processes. f=D CP (Gronau-London-Wyler)(GLW method) (small asymmetry) f=DCSD (Atwood-Duniets-Soni)(ADS Method) (additional problem of  D ) f= Dalitz analysis of D0-> K s      (GGSZ) (combines features of GLW & ADS depending on the location in Dalitz plot)- the dominant method [Giri, Grossman, Soffer, & Zupan, PRD 68, (2003), Bondar (Belle), PRD 70, (2004 )] Solve for  & ,      – r B =(|A 1 |/ |A 2 |)

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

36#  easuring  The prescription                      ….. But penguins (gluonic & E.W) can also lead to the same decays: With Tree alone Estimate  by constructing the isospin triangle(Gronau & London)  B->      sets the scale of the  correction

37# Good news for  very lucky angle! Longitudinal polarization dominates-  CP even & small B->      compared to B->     , B->       suppressed penguin contributions- Measuring  B (  +  0 ) = (5.75  0.42) B (  +  - ) = (5.20  0.25)  B (  0  0 ) = (1.30  0.21) A (  0  0 ) =  0.33 S (  +  - ) =  0.59  0.09 A (  +  - ) =  0.07 B (  +  0 ) = (5.75  0.42) B (  +  - ) = (5.20  0.25)  B (  0  0 ) = (1.30  0.21) A (  0  0 ) =  0.33 S (  +  - ) =  0.59  0.09 A (  +  - ) =  0.07 Br(B   x10 -6 Br(B   )=16.8+/- 2.2+/- 2.3x10 -6 Br(B   )=1.16+/ /- 0.27x10 -6 S= / C= / /  Longitudenal polarization fraction dominate (~90%) A=-C

38# Measuring  BaBar: at 68% c.l.  B   WA) Already the error is systematic (theory) dominated. At ~2/ab, expect  7 o  10 o depending on the size of B->      Measuring B->      its Time-dependent CP asymmetry will shrink errors further. Other ways of estimating penguin effects

39# Measuring sin2  Sin2  is a precision measurement now - the non-SM solution is essentially excluded B->J/  K* & 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