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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
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Charm Physics Potentials at B-factoriesXinChou 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 2001
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 2001
Leptonic Dsdecays, fDs 4.8 fb-1 CLEO, PRD 58,032002(1998) Method currentfDs=(280 29 28 34) MeV (7stat10sys 12Bfp)% with 400 fb-1(<1 (3-6) 2)% (4-7)% main sys. error: PID, tracking Model Dependent CLEO-B Extrapolations • 2.5 fb-1clns95-1387 • current(21.5stat13.4sys)%=24% • main sys. errors: random g and eff.BR • with 400 fb-1(1.73)%3.5% • main sys. Error: tracking • Model Dependent X. C. Lou, Snowmass 2001
4.7 fb-1 CLEO, PRD 62,072005(2000) methods: , B-decays, SL/Lifetime current B=(5.0 0.5 0.12)% (10stat15 12 8 8 5)% main sys. errors: p tag, modeling, Dp bkg, Lc/D spectra, Lc /D ID with 400 fb-1(1.1 (2-5) 2)% (3-6)% main sys. error: same as above, tracking Model Dependent CLEO-B Extrapolations • 1.79 fb-1 • CLEO PRL 72, 2328 (1994) • continuum data • with measured • current(3.25.4 5.0)%8.6% • main sys. errors: R+, eff., B(D0Kp) • with 400 fb-1(21.5 1.5)%3% • main errors: R+, eff., B(D0Kp) • Model Dependent X. C. Lou, Snowmass 2001
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)10-3 (E791, ALEPH) • Sentivity with 400 fb-1 data: for rmix (BaBar Phys. Book) X. C. Lou, Snowmass 2001
M. Benayoun et. al. Spectroscopy at B-factories Using Hard Photon Emission Modern Phys. Lett. A Vol. 14, No. 37, 2605-2614 (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 The ISR Method at B-factories X. C. Lou, Snowmass 2001
Production of Charm near Thresholds via ISR • •ISR production cross section • sISR = 01f(s,k)s(s´)dk • J. P. Alexander et. al. SLAC-PUB-450 • •Narrow resonance approximation • s(s´) = (3p/s´)GeeG0. • ( s´-MR)2+G02/4 • Example: e+e- y(2S) sISR=13.3 1.1 pb • provides a way to determine leptonic width Gee X. C. Lou, Snowmass 2001
Observation of ISR y(2S) signal by BABAR (8.9fb-1) DPF 2000 events 208 ±15 events M(mmpp)-M(mm) (GeV) M(mm) (GeV) mmpp Momentum (GeV) Fitted mmpp Momentum (GeV) X. C. Lou, Snowmass 2001
Estimate of ISR Charm Rates Source: J. M. Izen, W. Dundoodie, X. C. Lou, MKIII X. C. Lou, Snowmass 2001
Estimate of ISR Signal Events Source: J. M. Izen, X. C. Lou X. C. Lou, Snowmass 2001
Charm Cross-sections near Thresholds all D stotal 6 nb all Ds stotal 1 nb all Lc stotal 0.4 nb MKIII X. C. Lou, Snowmass 2001
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 ~1033 cm-2•s-1 X. C. Lou, Snowmass 2001