X. C. Lou, Snowmass Charm Physics Potentials at B-factories XinChou Lou, University of Texas at Dallas Introduction Physics Topics: branching fractions, leptonic decays, mixing Extrapolations from CLEO-B Initial State Radiation Production of Charm Events at B-Factories Measurements with ISR Charm at B-factories Summary
X. C. Lou, Snowmass Introduction BaBar projection 32 fb -1 by end of August 2001 ~400 fb -1 by end of 2004 CLEO-c plan Data-taking in Spring 2003 around charm thresholds, a few fb -1 Physics soon after Super B-factory after 2010? Look at physics of BaBar and CLEO-c in near term Super B-factory longer term
X. C. Lou, Snowmass CLEO-B Extrapolations Leptonic D s decays, f Ds 4.8 fb -1 CLEO, PRD 58,032002(1998) Method current f Ds =(280 29 28 34) MeV (7 stat 10 sys 12 B )% with 400 fb -1 (<1 (3-6) 2)% (4-7)% main sys. error: PID, tracking Model Dependent 2.5 fb -1 clns current (21.5 stat 13.4 sys )%=24% main sys. errors: random and eff. BR with 400 fb -1 (1.7 3)% 3.5% main sys. Error: tracking Model Dependent
X. C. Lou, Snowmass CLEO-B Extrapolations 4.7 fb -1 CLEO, PRD 62,072005(2000) methods:, B-decays, SL/Lifetime current B=(5.0 0.5 0.12)% (10 stat 15 12 8 8 5)% main sys. errors: p tag, modeling, Dp bkg, c /D spectra, c /D ID with 400 fb -1 (1.1 (2-5) 2)% (3-6)% main sys. error: same as above, tracking Model Dependent 1.79 fb -1 CLEO PRL 72, 2328 (1994) continuum data with measured current (3.2 5.4 5.0)% 8.6% main sys. errors: R +, eff., B(D 0 K ) with 400 fb -1 (2 1.5 1.5)% 3% main errors: R +, eff., B(D 0 K ) Model Dependent
X. C. Lou, Snowmass CLEO-B Extrapolations Mixing 9 fb -1 CLEO Conf 01-1 Standard Model 10 -8, Beyond SM 10 -(3-4) Method current best limits (5-9) (E791, ALEPH) Sentivity with 400 fb -1 data: for r mix (BaBar Phys. Book) Moder D ( ) r W ( ) N 0 ( 10 6 ) Sensivity ( ) KK K K
X. C. Lou, Snowmass The ISR Method at B-factories M. Benayoun et. al. Spectroscopy at B-factories Using Hard Photon Emission Modern Phys. Lett. A Vol. 14, No. 37, (1999) form factors, R scan, Upsilon states X. C. Lou and W. Dunwoodie Physics with ISR Events Produced at B-factory Experiments Presented at Hadron 99, Sept, 1999 Nucl. Phys. A675, 253 (2000) charmed hadrons, charmonia, exotics
X. C. Lou, Snowmass Production of Charm near Thresholds via ISR ISR production cross section ISR = 0 1 f(s,k) (s´)dk J. P. Alexander et. al. SLAC-PUB-450 Narrow resonance approximation (s´) = (3 /s´) ee 0. ( s´-M R ) 2 + 0 2 /4 Example: e + e - (2S) ISR = 13.3 1.1 pb provides a way to determine leptonic width ee
X. C. Lou, Snowmass Observation of ISR (2S) signal by B A B AR (8.9 fb -1 ) 208 ±15 events M( )-M( ) (GeV) M( ) (GeV) events Momentum (GeV)Fitted Momentum (GeV) DPF 2000
X. C. Lou, Snowmass Estimate of ISR Charm Rates Production interact. (GeV) fraction of sampling fun. cross-section (Coupled-channel model) produced events in 400 fb -1 of data ( 1000) (all) 3.94 ~1 nb~670 (charged + neutral) 4.0 ~6 nb~6, ~0.4 nb~450 J/ (2S) ~3.096 ~3.767 ~38 pb ~13 pb 15,200 5,200 Source: J. M. Izen, W. Dundoodie, X. C. Lou, MKIII
X. C. Lou, Snowmass Estimate of ISR Signal Events Decays Produced events in 400 fb -1 of data ( 1000) B.R. Det. Eff. (%) Events reconstructed Relative stat. error (%) Super B-factory ? (%) D s branching fraction ~ D s leptonic decays ~ (f Ds ) 0.5 ? (f Ds ) D + leptonic decay ~2, ~2, ,230 ~1.3~ c branching fraction ~ ~9~1 J/ (2S) leptonic width 15,200 5, , Source: J. M. Izen, X. C. Lou
X. C. Lou, Snowmass Charm Cross-sections near Thresholds all D total 6 nb all D s total 1 nb all c total 0.4 nb MKIII
X. C. Lou, Snowmass Summary Much improved charm measurements with CLEO methods and 400 fb -1 of data around Upsilon(4S) B.R. measurements will be systematics limited New ISR technique brings potentials for B-factory experiments charm physics before CLEO-c turns out physics results continuous e + e - data below Upsilon(4S) over all The ISR approach at a Super B-factory may enable exploration of physics between 10 > s > 0 GeV at ~10 33 cm -2 s -1