David B. MacFarlane SLAC EPAC Meeting January 25, 2006 BABAR Status & Plans David B. MacFarlane SLAC EPAC Meeting January 25, 2006

Pillars of BABAR physics program Highly constrained and redundant set of precision tests of weak interactions in the Standard Model Searches for physics beyond the Standard Model in a well understood & characterized environment Full program of flavor physics/CP violation measurements will provide a legacy of fundamental constraints on future New Physics discoveries Sensitivity to New Physics at LHC mass scales through rare decays and CP violation Discovery potential from large data sample across a whole range of beauty, charm, tau, two-photon, ISR physics Challenging measurements at the edge of sensitivity benefit enormously from operation of both PEP-II & KEK B Factories Jan 25, 2006 BABAR Status and Plans

PEP-II overall parameters and goals Units Design Oct 2005 I+ mA 2140 2940 I- 750 1740 Number of bunches 1658 1732 by* mm 15-20 11 Bunch length 15 11-12 xy 0.03 0.044-0.065 Luminosity x1033 3.0 10.0 Int lumi / day pb-1 130 727.8 More than 3x design More than 5x design Jan 25, 2006 BABAR Status and Plans

Weak Interaction in Standard Model + phases Unitarity Triangle as a summary of Standard Model b physics Jan 25, 2006 BABAR Status and Plans

Weak Interaction in Standard Model + phases Unitarity Triangle as a summary of Standard Model b physics CKM elements & quark masses are fundamental constants emerging from EW symmetry breaking CP violation Jan 25, 2006 BABAR Status and Plans

CPV in charmonium modes Interference of b ® c tree decay with mixing Jan 25, 2006 BABAR Status and Plans

3rd component: sizable Penguin diagram CPV in charmless modes 3rd component: sizable Penguin diagram Interference of suppressed b ® u tree decay with mixing Jan 25, 2006 BABAR Status and Plans

Remarkably good progress on gamma! Effect depends on ratio of two diagrams Suppressed Interference of color-allowed and color-suppressed tree decays Jan 25, 2006 BABAR Status and Plans

UT from sin2b & indirect constraints Overconstrained: growing set of independent measurements are consistent with CKM picture Now: looking for New Physics as correction to CKM Paradigm change! Jan 25, 2006 BABAR Status and Plans

UT from CP violation measurements alone New B Factory milestone: Comparable UT precision from CPV in B decays alone Overconstrained: subsets of measurements can be used to test for new physics Jan 25, 2006 BABAR Status and Plans

Interference of suppressed b ® s Penguin decay with mixing CPV in Penguin Modes Another implication of overconstrained: redundant approaches to same CKM parameter Interference of suppressed b ® s Penguin decay with mixing Jan 25, 2006 BABAR Status and Plans

Potential New Physics contributions SUSY contribution with new phases New physics in loops? “Internal Penguin” Jan 25, 2006 BABAR Status and Plans

Squark mass matrix (d sector) Revealing new physics B Factory LHC Squark mass matrix (d sector) Jan 25, 2006 BABAR Status and Plans

Summary after summer 2005 updates Charmonium s-Penguins Summer 05 results 2.4s between CP violation in s-penguin vs sin2b (cc) No sign of Direct CP About 0.5s loss vs Winter 2005 due to shift in charmonium average Jan 25, 2006 BABAR Status and Plans

BABAR CKM physics goals Impact FY2006 450 fb-1 FY2007 650 fb-1 FY2008 1000 fb-1 Precision measurement of sin2b Fundamental constant of the SM, whose precision is only limited by statistics Improve error by factor of two to 2% Precision measurement of CP asymmetry in penguin modes Primary approach to new physics in loop decays; presently discrepant with SM predictions at 2.4s level when averaged over all available modes Potentially reach the 4-5s level for average of all modes Could reach the 4-5s level for individual theoretically-clean modes Precision measurement of unitarity angle a Fundamental constraint on the UT Discovery of if it has SM branching fraction Isospin analysis in allows better than 10o measurement Precision measurement of unitarity angle g Fundamental tree-level constraint on phases and amplitudes originating from any new physics beyond the SM Pioneering measurements with 10-15o accuracy Determine to 5-10o precision Precision measurement of with inclusive & exclusive semileptonc B meson decays Fundamental tree-level constraint on amplitudes and phases originating from any new physics beyond the SM Inclusive decays reach 6.5% precision Exclusive decays reach 8% precision Jan 25, 2006 BABAR Status and Plans

Global CKM fit: 2008 95% contours Jan 25, 2006 BABAR Status and Plans

Summary: Physics plans for BABAR Goal for 2005-2006: double current data set Delay in Run 5 can be overcome by summer 2006 with extended running period, with substantial reduction in errors on CP violation asymmetries in rare decay modes Error on average of Penguin modes should reach 0.06 Goal for 2007-2008: double again to ~1 ab-1 Individual Penguin modes with errors in range 0.06-0.12 Suite of fundamental Standard Model measurements with substantially improved levels of precision Beyond 2008 might offer exciting opportunities if New Physics has been seen by B Factories & LHC Sensitivity to New Physics through rare decays, CP violation, & large data sample with a significant discovery potential Full program of flavor physics/CP violation measurements provide fundamental constraints on future New Physics discoveries Jan 25, 2006 BABAR Status and Plans