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Tau-charm physics at B factories. Stephen L. Olsen, Univ of Hawai’i Chinas workshop-2006 June 11-18, Beijing. 馬 鵬. BaBar and Belle. e + (3.5 GeV/c). e - (8 GeV/c). Peak luminosity 1.08 10 34 cm –2 s –1 Integrated luminosity 363 fb –1. Peak luminosity 1.62 10 34 cm –2 s –1
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Tau-charm physics at B factories Stephen L. Olsen, Univ of Hawai’i Chinas workshop-2006 June 11-18, Beijing 馬 鵬
BaBar and Belle e+ (3.5 GeV/c) e- (8 GeV/c) Peak luminosity 1.081034 cm–2s–1 Integrated luminosity 363 fb–1 Peak luminosity 1.621034 cm–2s–1 Integrated luminosity 602 fb–1 • Main purpose: Study CP violation in asymmetric e+e - (4S) BB • Both experiments have far exceeded their design goals • Approx. 1 ab-1 integrated flux combined
B Factories are t-charm factories On ECM (GeV) ~5M charm particles/fb-1 t+t-0.89 nb ~2M t’s/fb-1
t-physics at B factories • Mt • Spectral functions • Non-strange & strange • Rare decays • Forbidden decays
mt away from threshold Lafferty Charm 2006
Precision t measurements t- p-p0nt 79 fb-1
Strange spectral function Path to world-best measurements of |Vus| and ms Belle
Rare t decays Huge signals for t5pn decays limits on t7(8)pn decays
LFV decays, t- m- g, ℓ-ℓ-ℓ+, etc Lafferty Charm 2006
LFV limits from BaBar & Belle Lafferty Charm 2006 X10-7
constraints from tmg limits Lafferty Charm 2006
constraints from tmh limits Lafferty Charm 2006
Charm physics • Charmed particle spectroscopy • Rare decays • Form-factors • DDbar mixing
Sources of charm at B-factories c • Continuum • D*-tagged • Recoil tags • B decays • Radiative return c c D d u p q D y D
Old new charmed-strange particles BaBar BaBar
BDs DsJ decays are spin filters J=0 J=?; m=0 J=0 B DsJ Ds DsJ(2460) DsJ(2317)J=0 DsJ(2460)J=1 Belle
Masses coincide? See tak by Dmitrasinovic @ Charm 2006
New new charmed-strange particles DsJ(2860)D0K+ BaBar
Baryons, baryons, baryons.. Belle Belle c+- c+0 c++ Feeddown from c(2880)+ Signal c+sideband ISOTRIPLET!
Rare FCNC charm decays FCNC decays only occur in loop diagrams in SM: New physics can introduce new particles into loop Some models increase BF(cull) to 10-6—10-5 18 Paul D. Jackson Charm 2006
Unblinded Mass Distributions D+p+e+e– D+p+µ+µ– No signal for FCNC charm decays found Ds+K+e+e– Ds+K+µ+µ– Limits on yields extracted with unbinned likelihood fits Largest “signal” is ~1.5s in Lc+p+µ+µ–decays Lc+p+e+e– Lc+p+µ+µ– 24 Paul D. Jackson Charm 2006
Branching Fraction Limits (preliminary) Upper limits on BF (x10-6) at 90% CL Improved limits in 17 modes, more than order magnitude in 12 modes 26 Paul D. Jackson Charm 2006
Recoil-tagged Charmed mesons K p recoil p D*- K recoil pslow D0 „inverse“ fit recoil K/p+ e/µ- n p p additional primary mesons IP 3.5 GeV e+ e- 8 GeV D* g p mass-constrained vertex fits D Ktag p signal side tag side L. Widhalm Charm06
Form Factors – Comparison with Models Belle modified pole model D0 Kln lattice calculation ISGW2 model fit results simple pole D0 pln modified pole (poles fixed at theo. values) L. Widhalm Charm2006
CLEO-c untagged with v-reconstruction Simple Pole Model Modified Pole Model I Shipsey Charm2006 D0→-e+ D0→-e+ Preliminary
DDbar mixing limits Covered by A Schwartz
Charmonium production in B decays J = 0 or 1 j=½ j=½ Spectator model says Jcc= 0 or 1 should dominate exclusive BK(cc) decays.
charmonium states All sub-open-charm threshold states have been identified Discovered at B factories
Allowed decays all have Bf~10-3 hcK 0.9 x10-3 J/yK 1.0 x10-3 J/yK* 1.4 x10-3 J/yK12701.8 x10-3 y’K 0.7 x10-3 y’K* 0.9 x10-3 cc0K 0.6 x10-3 cc1K 0.7 x10-3 BK cc(J=2) still not seen
XYZ particles • X(3872) • p+p- J/y in BKp+p-J/y • Z(3930) • DD in gg DD • Y(3940) • wJ/y in BK wJ/y • Z(3940) • DD* in e+e- J/y DD* • Y(4260) • p+p-J/y in e+e-g p+p- J/y
gg Z(3931) DD at Belle sin4q (J=2) 4111 evts (5.5) M=3931 4 2 MeV =208 3 MeV Matches well to cc2’ expectations
X(3940) e+e-J/y + DD* e+e-J/y + X Seen in DD* but not DD; this impliescc1’ or hc” but e+e-J/y +cc0 not seen
Is the X(3940) the hc”? 3940 Mass is about 150 MeV too low
X(3872) BK p+p-J/y y’p+p-J/y X(3872)p+p-J/y S.K. Choi et al PRL 91, 262001 M(ppJ/y)
C=+1 is established X(3872)gJ/y seen in: M(pp) looks like a r (CDF) Belle X(3872)”w”J/y seen in Belle &
X(3872) has no obvious cc assignment hc” Mass & width way too small Angular dist. wrong 3872 cc1’ Mass & G(gJ/y) way too small Mass & width too small Angular dist wrong cc0’ h2 pp hc is allowed ppJ/y is isospin forbidden
Y(3940) in BK wJ/y M≈3940 ± 11 MeV G≈ 92 ± 24 MeV G(Y3940 wJ/y)> ~7 MeV (an SUF(3)-violating decay) M(wJ/y) MeV S.K. Choi et al. (Belle) PRL94, 182002 (2005)
Is the Y(3940) the cc1’ ? Y(3940) w J/y enhanced by FSI ? w D Y FSI D* J/y It seems strange (to me) that an SU(3)-violating process can “short out” an SU(3)-allowed process If the Z(3930) is the cc2’ (which seems likely) the Y(3940) mass is too high for the cc1’
Y(4260) 10.58 GeV M=4259 8 MeV G = 88 23 MeV 4.26 GeV not seen in s(e+e-hadrons) at Ecm =4.26 GeV Y(4260) BES s(e+e-hadrons) scc~5nb J/ sideband B. Aubert et al. (BaBar) hep-ph/0506081 J.Z. Bai et al. (BESII) PRL 88 101802 Well above DD & DD* threshold but wide & found in a suppressed mode??
CLEO-c results on the Y(4260) PRL 96 162003 (2006) 58 12 pb G(Y4260)ppJ/y > ~1.8 MeV >10x higher than what we are used to
Is the Y(4260) a hybrid? Expect distortions of p+p-J/y line shape DD0*0 DD0’0 DD1 No sign of YDD** “turn-ons”