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Charm at super Belle. Jolanta Brodzicka (Krakow) Super KEKB Meeting 10 December 2008. Outline. Introduction Leptonic and semileptonic D (s) decays Rare decays Charmonium production in e + e - Spectroscopy: c c and exotics Summary D 0 - D 0 mixing and CPV covered on Thursday.
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Charm at super Belle Jolanta Brodzicka (Krakow) Super KEKB Meeting 10 December 2008
Outline • Introduction • Leptonic and semileptonic D(s) decays • Rare decays • Charmonium production in e+e- • Spectroscopy: cc and exotics • Summary D0-D0 mixing and CPV covered on Thursday
Charm at SuperB Factory • B Factory at Y(4S) is a factory of charm: σ(e+e-→BB)~1.1nb σ(e+e-→cc)~1.3nb • Physics of charmed hadrons • test theoretical calculations (QCD and lattice QCD) • improve precision of CKM related measurements • search for new phenomena within SM and beyond • Can we compete with Charm Factory? * Charm Factory: Cleo (0.6/fb) + BESIII (2-3 years of running)
Leptonic D(s)+ decays • Partial width for P→lν decay P=D+,Ds+ • Leptonic part: Vcd (Vcs) • Hadronic part: decay constants: fD (fDs) (nQCD involved: requires LQCD) • Measurement of fD and fDs (fDs /fD): test of LQCD • Impact on B decays e.g. constraint of ‘mixing side’ of UT: |Vtd/Vts|~ √(Δmd/Δms )(mBd/mBs) fBs/fBd More precise knowledge of fBs/fBd needed! = 0.2060 0.0007(exp)+0.0081(LQCD) -0.0060
PRL 100, 241801 (2008) tagged Ds 32K Mrecoil(DKXγ) signal Ds 169±16±8 M2recoil(DKXγμ) Ds+→μν at Belle • Ds+→μν most accesible: Γ(τν):Γ(μν):Γ(eν)=10:1:10-5 BR(τ→hν)~11% • e+e-→DKX Ds* Ds*→Dsγ X=nπ(γ) • Number of tagged Ds from Mrecoil(DKXγ) → normalization for absolute BF • Number of signal Ds+→μν from M2recoil(DKXγμ) • For 548/fb : uncertainty of ~10% and needs improvement!
Leptonic decays: status • Experiment vs lattice: fD:consistent fDs :~3σ discrepancy • Statistical fluctuation? • LQCD to be reexamined? • H+ or leptoquarks contribute? PRL 100, 241802 (2008) • Belle method established for Ds+→μν: to be used for D+→μν (BF~4*10-4) with sBelle sample
Semileptonic D(s) decays • Partial width of D→P’lν P’=K,π • Form Factor f+(q2) describes hadronic part • Simple pole model: Modified pole model: pole: D* for D0→πlν, D*s for D0→Klν • Ds→φlνΓ=Γ(q2,χ,θl,θV) Form Factors: V(q2), A1(q2), A2(q2) measured: rV= V(0)/A1(0) r2=A2(0)/A1(0) • FF (normalization & q2 dependence) to test LQCD • To tune/check calculations in B sector e.g.: |Vub| from B→πlν accuracy ±3% from BF ±10-14% from Form Factor Goal: test LQCD to 5% q2 =(pν + pl)2
PRL 97, 061804 (2006) mν2 D0→K/πlν at Belle 282/fb • e+e- →Dtag(*) XDsig* Dsig*→D0πs X=nπK • Number of tagged D0 from Mrecoil(Dtag(*)Xπs) (→inclusive D0 sample, normalization) • Number of signal D0→K/πlν from Mrecoil(Dtag(*)XπsK/πl)=mν2 LQCD: 0.040±0.002(stat)±0.005(syst) D0→Klν f+K(0) = 0.695 ± 0.007 ± 0.022 f+π(0) = 0.624 ±0.020 ±0.030 In agreement with CLEO D0→πlν
f+π(q2) for D0→πlν errors for 5/ab Prospects of (semi)leptonic D(s) decays
10-6 10-7 10-8 D0 → μμ ee μe Rare decays • Feasible exp. ground to look for New Physics: rare (loop) decays, mixing, CPV • Leptonic rare/LFV decays: D0→μμ, ee, μe • Belle sensitivity for 690/fb (preliminary MC study) • D0→πll SM~10-6 • radiative decays SM~10-6 -10-4
357/fb Charmonium production in e+e- • NRQCD for prompt ψ production: ψgg ~ψg >>ψcc (LO) • Experiment: • e+e-→J/ψ(cc) dominates: σ(e+e-→J/ψ (cc) )=0.74±0.08+0.09-0.08 pb σ(e+e-→J/ψ non-(cc) )=0.43±0.09±0.09 pb(for 673/fb) • it’s a factory of charmonia with C=+ and J=0 σ*BF>2 [fb] (for 155/fb) • LO + NLO +relativistic corrections can accomodate experimental results • Open questions:NNLO and/or color octet needed?
e+e-→J/ψηc 693/fb M(DD) M(DD*) X(3940) M(D*D*) X(4160) Charmonium production in e+e- • Experimental role is still leading To do with sBelle: • Precise measurements of e+e-→J/ψ(cc) and ψ(2S)(cc) (x-sections, production/helicity angle) • Study of e+e-→ηc(cc), χcJ(cc), ηc(2S)(cc) • e+e-→J/ψD(*)D(*) : new states in D(*)D(*) system • high statistic measurement of mass/width/shape • angular analysis of X states needed
m(DD) predicted measured Charmonium spectrosocpy
ηc(1S) mass: 2980.3±1.2 MeV ηc(1S) width: 26.7±3.0 MeV Charmonia below DD • ηcηc’: mass, width, line shape measurement • Precise measurements of hyperfine splittings: m(ηc)– m(ψ) →test of models and LQCD (hyperfine splitting underestimated) Effect of ηc line shape? Only in M1 transition ψ→γηc? • ηc’: KsKπ is only known decay; PDG08: m=3637±4 MeV Γ=14±7 MeV • B→Kηc and ηc→KsKπ at Belle with 500/fb m and Γ accuracy: ηc: σ(m)~2MeV σ(Γ)~3MeV ηc’: σ(m)~6MeV σ(Γ)~9MeV • sBelle: precision + other decay modes
Charmonia below DD • hc(1P) finally observed by Cleo: ψ(2S)→π0hc hc→γηc • m(hc) = 3525.20 ± 0.18 ± 0.12 MeV • hyperfine splittng χc(3PJ) – hc(1P1)~0 challenge for theory • Confirmation of hc at sBelle? • B→hcK hc→ηcγ factorization violating mode Belle with 253/fb: BF<3.8*10-5 @90%C.L assuming BF(hc→ηcγ)=0.5 • e+e-→ηchc , χc0hc : in recoil of C=+1 charmonia ηc , χc0 reconstructed with BF~O(10-3) → 5/ab needed
DD ? Y(4350) (4160) DD* Y(4008) Y(4260) D*D* (4415) (4040) Y(4660) DDπ Λc+Λc– Charmonia above DD • Parameters of vector states: ψ(3770), ψ(4040), ψ(4160), ψ(4415) • From fit to inclusive hadronic x-section by BES • Belle: access to 1-- states through ISR • Fits to exclusive x-sections: strong model dependence. Fits to be attempted with more precise x-section measurements. • Missing components requiring sBelle data: DD*π, D*D*π, DsDs, DsDs*, Ds*Ds* • Insight into Y family
e+e-→p+p-J/y Y(4260) Y(4008) e+e-→p+p-y’ Y(4360) Y(4660) 1-- Y family Exotic family? • Large Γ(Y→ψππ)~O(MeV) • Small Γ(D(*)D(*)): qualitative conclusion • Not enough empty 1-- cc slots to fill More ISR studies using sBelle data: • Conclusion on Y(4008)? • Y→ψπ0π0 check of isospin relation • Y→DD1(2420), D*D*0 →DD*π test of molecular scenario • Y→DD1(2420), J/ψη,J/ψη’, χcJω test of hybrid scenario
B KD0D*0 D*→Dγ D*→D0π0 B0→XK0 Ns=30±7 B+→XK+ Ns=125±14 605/fb M(J/ψπ+π-) M(J/ψπ+π-) m(X)=3872.6+0.5-0.4±0.4MeV Γ=3.9+2.5-1.3+0.8-0.3 MeV Action items for X(3872) 605/fb Studies of B→X(3872)K: • X(3872)→D0D*0 : mass, width, line shape • X(3872)→D0D0π0 • X→J/ψπ+π- width • X→J/ψπ0π0 check isospin relation • X→J/ψπ+π- π0 isospin violating mode • X→J/ψπ+π0 critical for 4-quark scenario • X→J/ψγ signal 14±4 (4σ) for 256/fb X→ψ’γ, χc1γ problematic for molecular scenario
Z+(4050) Z+(4248) Z+(4430) M(χc1π+) M2(ψ’π+) Z± cc-like states Further studies with sBelle data: • Precision mass/width • Spin-parity determination • Search for Z0→ψπ0 , χc1π0 test of [cu][cd] tetraquark scenario • Z→D*D1(2420)→D*D*π test of molecular scenario • Search for new Z±’s: Z→DD, D*D, D*D* Z→J/ψπ+ ,ηcπ+ ,... Results of Dalitz plot fit for: B→ Kψ’π+ and B→ Kχc1π+ –̶̶̶̶̶̶ –̶̶̶̶̶̶ for model without Z(s) –̶̶̶̶̶̶ –̶̶̶̶̶̶ for model with Z(s)
Summary • A lot of charm studies with Belle data • Good prospects for more with Super Belle: precision (semi)leptonic D(s) decays access to rare decays understand charmonium production identify XYZ states study of baryons/mesons
Hadronic x-sections • From CLEO: scan at 3.97-4.26GeV in 12 points • Total hadronic x-section above DD from BES • Belle: sum of all measured exclusive contributions (3770) (4160) Y(4008) Y(4350) (4415) Y(4260) Y(4660) (4040) Durham Data Base