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The 5-th International Conference on Quarks and Nuclear Physics. Hadron Spectroscopy from B Factories. Galina Pakhlova ITEP&Belle Collaboration. Beijing, September 21-26, 2009. B-factories e + e – → (4S) and nearby continuum: E cms ~ 1 0 .6 GeV L ~ 10 34 /cm 2 /s
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The 5-th International Conference on Quarks and Nuclear Physics Hadron Spectroscopy from B Factories Galina Pakhlova ITEP&Belle Collaboration Beijing, September 21-26, 2009
B-factories e+e–→(4S) and nearby continuum: Ecms ~ 10.6 GeV L ~ 1034/cm2/s 950 + 530 fb-1 in total Charm hadrons from B-meson decays, initial state radiation (ISR), double cc production, continuum production and γγ fusion Galina Pakhlova, ITEP
Charm meson spectroscopy Galina Pakhlova, ITEP
q charmed mesons c Charmed mesons Heavy-light system Qq Q = c quark q = u, d, s light quarks cu = D(*)+, cd = D(*)0charmed mesons cs=Ds(*)± charmed strange mesons • L = 0 S-wave ground states • D&D* Mark1 • L = 1 P-wave exitations, jq= 1/2 or 3/2 • jq= 3/2 are narrow and easy to find • D1(2420) & D2(2460) ARGUS&CLEO • jq= 1/2 are broad • D0(2400) & D1(2430) Belle in B→Dππ (Dalitz plot analysis) masses and widths are in good agreement with expectations n(2S+1)LJ n radial quantum number Sc spin of c-quark Sqspin of q light quark L relative orbital ang. mom. L = 0, 1, 2 ...correspond to S, P, D jq= Sq + L J = Sc + Sq + L P = (–1)L+1parity Galina Pakhlova, ITEP
D*sJ(2860)± D*K s D*s1(2700)± DK Ds1(2460)± D*s0(2317)± js = 3/2 js = 1/2 L = 1 L = 0 c Charmed strange mesons • L = 0 S-wave ground states • Ds+Cleo 83, Ds*± Slac 84 • L = 1 P-wave excitations, jq= 1/2 or 3/2 • jq= 3/2 are narrow • Ds1(2536)& Ds2(2573) ARGUS 89&Cleo94 • jq= 1/2 presented real surprise • D*s0(2317)+, Ds1(2460)+BaBar 03, Cleo 03 • extremely narrow • ~100 MeV lighter than expected , below D(*)K threshold • conventional decay modes are forbidden • only electromagnetic isospin violated decays are allowed • Now the theory can explain this mass shift • Higher mass excitations • D*sJ(2700)+→ DK, in e+e → DKX BaBar 06 • D*s1(2700)+→ DK, in B → DDK Belle 08 • DsJ(2860)+→ DK, in e+e → DKX BaBar 06 are they the same state? Mass and width agree well Belle measured J=1 Galina Pakhlova, ITEP
confirmed in D*K Ds1(2700) confirmed in D*K Ds2(2573) DsJ(2860) arXiv: 0908.0806 DsJ(3040) 470fb-1 newin D*K Ds1(2700) DsJ(2860) M(D*K) M(D0K+) Ds2(2573) Ds1(2700) DsJ(2860) M(D+Ks0) New study of inclusive D(*)K frome+e→D(*)KX Ds1(2700) and DsJ(2860) havenatural JP=1,2+,3... DsJ(3040) not seen in DK: unnatural JP=0,1+,2 ... Interpretations: n=2 radial excitations? L=2 orbital excitations? Galina Pakhlova, ITEP
Charmonium spectroscopy Galina Pakhlova, ITEP
c c Conventional Charmonium in Quark Model • Above open charm threshold • five conventional states are measured • broad states are expected n(2S+1)LJ n radial quantum number S total spin of q-antiq L relative orbital ang. mom. L = 0, 1, 2 ...correspond to S, P, D J = S + L P = (–1)L+1parity C = (–1)L+Scharge conj. • Below open charmthreshold • all expected charmonium statesare observed • most are narrow Galina Pakhlova, ITEP
Exotic charmoniumlike states Multiquark states Molecular state two loosely bound charm mesons quark/color exchange at short distances pion exchange at large distance Tetraquark tightly bound four-quark state Charmonium hybrids States with excited gluonic degrees of freedom Hadro-charmonium Specific charmonium state “coated” by excited light-hadron matter Threshold effects Virtual states at thresholds Charmonium states with masses shifted by nearby D(*)D(*) thresholds March 1976 November 1976 Search for exotics: states with ... • JPC forbidden for charmonium • Extremely narrow width • Non-zero charge [cucd], strangeness [cdcs] or both [cucs] • Obvious sign of multiquark states ─ ─ ─ Exotics more easier to identify among cc and bb states ─ ─ Galina Pakhlova, ITEP
CP X(3872) B→Xsγ 479 Belle citation count 451 330 Phys.Rev.Lett.91262001, (2003) 6th anniversary! Galina Pakhlova, ITEP
X(3872) observation PRL91,262001,2003 first PRD71,071103,2005 PRD73,011101,2006 PRL93,162002,2004 10s Tevatron: in pp collisions • prompt production • B decays (16.1±4.9±1.0)% • similar to (2S) ─ M(J/π+π–) PRL93,072001,2004 X(3872)first seen in B →K J/π+π– • MX close to D0D*0 threshold • (not clear below or above) • M = 3871.4±0.6 MeVPDG07 • MX – MDD* = (–0.40.7) MeV/c2 • surprisingly narrow: • Γtot < 2.3 MeVat 90% CL • M(ππ) tends to kinematic limit • ππ=? Isospin violation! Galina Pakhlova, ITEP
Fit toM(ππ) favorsL = 0; PX = +1 JPC of the X(3872) hep-ex/0505038 PRL96,102002(2006) PRL 102, 132001 (2009) 3.6σ 3.5σ 424fb–1 X(3872)→J/γ X(3872)→(2S)γ • X(3872)→J/ observation fixesCX= +1 • confirms that intheX→J/ψππdecay(ππ)=ρ • Γ(X→J ) / Γ(X→J/ π+π–) = 0.14 ± 0.05small • X → J/ωobservation • Br (X → J/ω) / Br (X→J/π+π–) = 1.0 0.4 0.3 • large isospin violation • Unlike conventional charmonium CDF 790fb-1: PRL98, 132002(2007) X → J/ ππangular analysis JPC = 1++or2–+ • JPC = 2–+disfavored by X(3872) decay to both J/γ and (2S)γ • The most likely JPC = 1++ • Relatively large Br(X → (2S) γ) is inconsistent with a pure D0D*0 molecular interpretation for X(3872) • Favors cc - D0D*0 mixing modelsSwanson PLB 598, 192 (2004) Br(B±→XK±) Br(X→J/γ) = (2.8 ± 0.8 ± 0.2) · 10–6 Br(B±→XK±) Br(X→(2S)γ) = (9.9 ± 2.9 ± 0.6) · 10–6 Galina Pakhlova, ITEP
Charged and neutral partners of X(3872)? PRD71,031501,2005 B0 B- X(3872)– X(3872)– M(J/π–π0) M(J/π–π0) diquark-antidiquark models Xu and Xdfrom B0and B+ decays ΔMX = 8 ± 3 MeV Maiani et al PRD71, 014028 MX=(2.7 ±1.6 ±0.4 )MeV/c2 MX=(0.18 ± 0.89 ±0.26 )MeV/c2 Br(B0 →XK0)/Br(B+ →XK+) = 0.41 ± 0.24 ±0.05 0.82 ± 0.22 ±0.05 Br(B0 →XK0) Br(X →J/)= (6.65 ± 1.63 ± 1.00) · 10–6 B+→XK+ B+→XK+ 12.8 605 fb-1 8.6σ 413 fb-1 PRD77,111101 (2008) arXiv:0809.1224 B0→XK0s B0→XK0s 2.3σ 5.9 Precise mass measurement : Mx = (3871.46 ± 0.37 ± 0.07) MeV/c2 NO evidence of X–(3872) J/–0 excludes isovector hypothesis X(3872)→J/ψπ+π– Galina Pakhlova, ITEP
One state or two states?X(3872)→J/ψπ+π– arXiv:0906.5218 2.4 fb–1 disfavors diquark-antidiquark models Mass (X(3872)→J/ψπ+π– ) New the most precise mass measurement! new average (3871.46±0.19) MeV/c2 MD0 + MD*0 (3871.81±0.36) MeV/c2 Precision needs to be improved Δm = 0.35 ± 0.41 MeV/c2 Compare the expected width of one/two state hypotheses to the measured width in the data Mass difference between two possible states m < 3.6 MeV/c2 at 95% CL Galina Pakhlova, ITEP
X(3872) ≠ X(3875)? PRD77,011102,2008 PRL97,162002,2006 6.4σ B+& B0D0D*0K 4.9σ B KD0D0π0 347fb-1 arXiv:0810.0358 D*→Dγ B KD0D*0 605 fb-1 D*→D0π0 1.4σ 2 σ Disfavor tetraquark hypothesis! Flatte ala Hanhart et al, PRD76, 034007 (2007) vs phase-space modulated BWsimilar result PDG E.Braaten et al. arXiv: 0907.3167 … in a narrow decaying DD* molecular system the width of D* distorts the decay line shape. Fitting DDπ or DD* by BW does not give reliable values for either the mass or width… Galina Pakhlova, ITEP
B0 →X(3872)K+π– 5σ X(3872) sideband X(3872)→J/ψπ+π– arXiv 0809.1224 non-resonant Kπ 605 fb-1 K*0→Kπ M(Kπ) Kπχc1 arXiv 0809.1224 PRD 71 032005 KπJ/ψ Kπψ(2S) PRD 74 072004 M(Kπ) M(Kπ) M(Kπ) Br(B0 →XK*0)Br(X→J/ψπ+π–) < 3.4×10–6 90% CL Br(B0 →X(K+π–)non res) Br(X→J/ψπ+π–) = (8.1±2.0+1.1–1.4)10–6 non-resonant Kπ dominates! unlike B0 →K+π–charmonium Galina Pakhlova, ITEP
Interpretations of X(3872) • Conventional charmonium • JPC=1++ corresponds to c1(23P1) • expected Γ(c1′J/) / Γ(c1′J/ ) ~ 30, measured ratio < 0.2 • ~ 100MeV/c2lighter than expected D0D*0 molecular state: (the most popular option) N.A. Tornqvist, E.S .Swanson, F.E. Close and P.R. Page, M.B. Voloshin, E. Braaten et al. • MX ~ MD0 + MD*0 is not accidental • JPC=1++ (D0D*0 in S-wave) • DD* decay • Small X(3872) → J/ψγ is expected Problems: • too large X(3872) → ψ(2S)γ • too small binding energy: D0andD*0too far in space to be produced in high energy pp collisions Possible solution:Mixture of DD* molecule and 23P1 charmonium state? Tetraquark (cq)(cq): L. Maiani, A.D. Polosa, V. Riquer, F. Piccini; D. Ebert, R.N. Faustov, V.O. Galkin • 3 states (cu)(cu), (cd)(cu), (cd)(cd) with a few MeV mass splitting • no evidence of neither neutral doublet nor charged partner Hybrid (ccg)F.E. Close and P.R. Page Threshold cuspD.V. Bugg Galina Pakhlova, ITEP
Y(4660) Y(4260) Y(4325) Y(4008) c X(4630) e+ e+ e– s=E2cm-2EEcm 1– – c e+e−→ 1– – final states via ISR Galina Pakhlova, ITEP
e+e–→J/ψπ+π–γISR Y(4260) ... Y(4008)? arXiv:0808.1543 NEW Y(4260) 344±39 ev Y(4008) 454 fb-1 Br(J/ψπ+π–)Γee , eV Solution1 Y(4008)Solution2 < 0.7 90% CL Solution1 Y(4260)Solution2 7.5±0.9±0.8 Absence of open charm production is inconsistent with conventional charmonium Galina Pakhlova, ITEP
e+e–→ψ(2S) π+π–γISR Y(4360), Y(4660) ... PRL 98, 212001 (2007) PRD 78, 014032 (2008) Y(4360)→ψ(2S)ππ Y(4660)? PRL 99, 142002 (2007) Y(4360) Y(4660) 6.1σ 298 fb-1 Y(4660) 5.8σ Y(4360) 8σ 670 fb-1 2-BW fit with interference Solution1Solution2 Br(ψ(2S)π+π–)Γee , eV Y(4360) Y(4660) Combined fit to BaBar&Belle data on e+e–→(2S) π+π–γISR Best measurements of Y(4360) and Y(4660) Assume all the cross sections are due to Y(4360) and Y(4660) added coherently Absence of open charm production is inconsistent with conventional charmonium Galina Pakhlova, ITEP
4660 4350 4260 4008 Potential models & Y states No room for Y states among conventional 1– – charmonium 33S1 = (4040) 23D1 =(4160) 43S1 =(4415) masses of predicted 33D1 (4520) 53S1 (4760) 43D1(4810) are higher (lower) Galina Pakhlova, ITEP
e+e–→Λc+Λc–γISR &X(4630) Phys.Rev.Lett.101,172001(2008) e+e–→Λc+Λc–γISR • no peak-like structure • X(4630) ≡ Y(4660)?JPC=1 • dibaryon threshold effect? • like in B→pΛπ, J/ψ→γpp • X(4630) = Y(4660)D.V.Bugg • X(4630) = Y(4660) = charmonium state53S1 or43D1 • J.Segovia, A.M.Yasser, D.R.Entem, F.Fernandez • charmonium state63S1B.Q.Li and K.T.Chao • Threshold effect E.Beveren, G.Rupp • Point-like baryons R.B.Baldini, S.Pacetti, A.Zallo • X(4630) = Y(4660) =tetraquark D.Ebert, R.N.Fausov, V.O. Galkin Galina Pakhlova, ITEP
D*D* Y(4260) Y(4008) ψ(4040) PRL98, 092001 (2007) ψ(4160) Y(4360) DD* PRD77,011103(2008) DD ? DDπ PRL100,062001(2008) ψ(4415) arXiv:0908.0231 DD*π New PRL101,172001(2008) Y(4660) Λc+Λc– Y states vs inclusive & exclusive cross sections e+e–→hadrons • Peak positions forM(J/) &M((2S))significantly different • Y(4260)mass corresponds to dip ininclusive andD*D*cross sections • Y(4008) mass coincides with DD* peak • Around Y(4360)mass all measured cross sections are smooth • Y(4660) mass is close to Λc+Λc–peak • Signigicant “peak-like” enhancement near 3.9 GeV in ee→DD coupled channel effect? or something else? Galina Pakhlova, ITEP
Interpretations of Y states Y(4360) &Y(4660) are conventional charmonium with shifted masses Y(4360) = 33D1 , Y(4660) = 53S1 G.J Ding, J.J.Zhu, M.L.Yan, Phys.Rev.D77:014033 (2008) A.M.Badalyan, B.L.G.Bakker, I.V.Danilkin, Phys.Atom.Nucl.72:638-646,(2009) 43S1 ≠ ψ(4415) =43D1(4661); Y(4360)=43S1(4389) , Y(4660)=53S1 (4614)or43D1(4661) J.Segovia, A.M.Yasser, D.R.Entem, F.Fernandez Phys.Rev.D78:114033,(2008). Charmonium hybrids Zhu S.L.; Close F.E.; Kou E. and Pene O. The lightest hybrid is expected by LQCD around 4.2 GeV The dominant decays Y(4260)→D(*)D(*)π, via virtual D** Hadro-charmonium Specific charmonium state “coated” by excited light-hadron matter S.Dubinskiy, M.B.Voloshin, A.Gorsky Multiquark states [cq][cq] tetraquark Maiani L., Riquer V., Piccinini F., Polosa A.D. DD1 or D*D0 molecules Swanson E.; Rosner J.L., Close F.E. S-wave charm meson thresholdsLui X. Galina Pakhlova, ITEP
New arXiv:0908.0231 Upper Limit Y(4260) ψ(4415) ψ(4415) UL at 90% CL Exclusive e+e− D0D*–+cross-section • No evident structures: only UL’s !!! • Baseline fit: • RBW for (4415)&threshold function for non-resonant contribution without interference between amplitudes • To obtain limits on XD0D*–+, X=Y(4260), Y(4360), Y(4660), X(4630) perform four fits each with one of the X states, (4415) and non-resonant contribution • Fix masses and total widths from PDG Interference could increase these UL’s by factors of 2−4 depending on the final state (for destructive solutions) σ(e+e–→ψ(4415))×Br(ψ(4415)→D0D*–π+)< 0.76 nb at 90% CL Br(ψ(4415)→ D0D*–π+) < 10.6 % at 90% CL Galina Pakhlova, ITEP
DD DD* D*D* DDπ DD*π Λ+c Λc Sum of all exclusive contributions • Only small room for unaccounted contributions • Charm strange final states • Limited inclusive data above 4.5 GeV • Charm baryons final states Galina Pakhlova, ITEP
X Z Y Y? 3940 family Galina Pakhlova, ITEP
Z(3940) in γγ→DD PRL96,082003(2006) Z Z→DD 5.3σ 395fb-1 Helicity distribution e+ J=2 e+ γ D J=0 γ D e– e– only 0++, 2++ M= (3929±5±2) MeV/c2 Гtot = (29±10±2) MeV Production mechanism, helicity distribution, measured Γγγ indicate Z(3940) to be c2′ = 23P2 conventional charmonium state! for J = 2 × B(ZDD) = (0.18 ± 0.05 ± 0.03) keV Galina Pakhlova, ITEP
X(3940) and X(4160) ine+e− →J/ D*D(*) PRL100, 20200 (2008) • Possible assignments are JPC=0–+ • X(3940) = 31S0 = ηc(3S) • X(4160) = 41S0 = hc(4S) • decay to open charm final states like conventional charmonium • production mechanism fix C=+1 • known states produced in e+e− →J/ cc have J=0 • not seen in DD decay, exclude JPC=0++ • For bothX(3940)andX(4160)the masses predicted by the potentialmodels are~100250 MeVhigher M = 3942 ±6 MeV tot =37 ±12 MeV +7 −6 +26 −15 6.0 X(3940) → DD* 670 fb-1 +25 −20 M= 4156 15 MeV tot = 139 21 MeV +111 − 61 5.5 X(4160) → D*D* Galina Pakhlova, ITEP
Y(3940) → J/ PRL 94, 182002 (2005) B→YK Y→J/ 8.1σ 253fb-1 PRL 101, 082001 (2008) B →YK 348fb-1 B0→YK0S ArXiv:0810.0358 PRL 98, 082001 Mass above DD threshold but J/partial widthis too large for conventional charmonium X(3940) ≠ Y(3940) @ 90% CL NB0/NB+ = 0.27+0.28–0.23+0.04–0.01 ~3σbelow isospin expectations Galina Pakhlova, ITEP
γγX(3915) ωJ/ψ preliminary BW + background e+ e+ N = 55 ±14+2–14 events γ J/ 7.7 σ X fit with no BW term γ ω e– e– M(ωJ/ψ) J = 0, 2 only M = 3914 ±3± 2 MeV/c2 Γ = 23± 10+2–8 MeV • 2σ difference with Z(3930) mass • good agreement with BaBar’s Y(3940) mass seen in ωJ/ψ for JP = 0+× B(X(3915)ωJ/ψ) = (69 ± 16+7–18) eV ωJ/ψpartial width ~ 1 MeV is quite large for conventional charmonium Galina Pakhlova, ITEP
Hidden strange & hidden charm Galina Pakhlova, ITEP
PRL102, 242002 (2009) 14±5 events 3.8σ 2.7 fb-1 M(J/ψφ) – M(J/ψ) Preliminary B→J/ψφK 7.5+4.9–4.4 events 1.9σ M(J/ψφ) B→J/ψφK, Y(4140)J/ψφ M = 4143.0± 2.9 ±1.2 MeV/c2 Γ = 11.7+8.35.0 ±3.7 MeV Br(B+→YK+) × Br(Y→J/φ) = (9.0 ±3.4 ± 2.9) × 10–6 M~2M(D*s) : D*sD*s molecule? [cscs] tetraquark? M(J/ψφ) fit with Y(4140) parameters fixed Y(4140) is not confirmed Br(B+→YK+) × Br(Y→J/φ) < 6 × 10–6 @ 90% CL Galina Pakhlova, ITEP
γγ φJ/ψ 825fb-1 8.8+4.2–3.2 events e+ e+ 3.9σ γ J/ Y φ γ Y(4140) Preliminary e– e– J = 0, 2 only M = (4150.6± 5.1 ±0.7) MeV/c2 Γ = (13.3+17.9–9.1 ± 4.1) MeV No Y(4140)→J/ψφ signal in γγ fusion New Y(4350)? excited P-wave charmonim? D*sD*s0 molecule? for JP=0+× B(Y(4350) φJ/ψ) = (6.49+3.2–2,3 ± 1.1) eV for JP=2+× B(Y(4350) φJ/ψ) = (1.5+0.7–0.5 ± 0.3) eV Galina Pakhlova, ITEP
Z±(4430) …Z1±...Z2± Galina Pakhlova, ITEP
Z(4430)+ first charged charmoniumlike state ??? M2((2S)), (GeV2 ) PRL 100, 142001 (2008) 548 fb-1 K*(1430) K*(890) M2(K), (GeV2 ) 6.5 M(p+y(2S)) Cannot be conventional charmonium or hybrid B → KZ, Z(4430)+ → π+ψ(2S) K=K–,K0s ; ψ(2S) →ℓ+ℓ–, π+π–J/ψ after K* veto Fit: S-wave BW + phase space like func M = (4433 ± 4 ± 2) MeV Γ = (45+18-13+30-13) MeV Br(B→KZ) × Br(Z→ψ(2S)π) = (4.1 ± 1.0 ± 1.3) ×10-5 Br±/Br0=1.0 ± 0.4 Shows up in all data subsamples • Could the Z(4430) be due to a reflection from the Kπchannel? • S- P- & D-waves cannot make a peak (+ nothing else) Galina Pakhlova, ITEP
413fb–1 S-wave P-wave D-wave PRD79:112001 (2009) 4430 M2(K0π–) M2((2S)), (GeV2 ) M2(K+π–) BaBar search for the Z(4430)– B–0 →J/ψπ–K0+ ; B–0 →ψ(2S)π–K0+ • Detailed study of K π– reflections into the J/ψπ– and ψ(2S) π– masses (S, P, D waves) to describe background for both J/ψ and ψ(2S) modes • Fit to J/ψπ– and ψ(2S) π– distributions: background + BW (free mass & width). Observe ~2σ fluctuations below/above background in J/ψ and ψ(2S) modes • At M = 4430 MeV/c2 & Γ = 45 MeV Br(B0→Z–K+, Z–→ψ(2S)π–) < 3.1 x 10-5 @ 95% CL “For the fit … equivalent to the Belle analysis…we obtain mass & width values that are consistent with theirs,… but only ~1.9σ from zero; fixing mass and width increases this to only ~3.1σ…” Galina Pakhlova, ITEP
Reanalysis of B →Kπψ(2S) data using Dalitz Plot techniques 1 3 2 4 A B M2(ψ(2S)π), (GeV2 ) C M = (4443+15–12+17–13) MeV/c2 Γ= (109+86–43+57–52) MeV 5 PRD 80, 031104 (2009) 3 K* veto applied Mass & significance similar, width & errors are larger M2(K), (GeV2 ) With Z(4430) 6.4s PRL 100, 142001 (2008) M = (4433 ± 4 ± 2) MeV/c2 Γ = (45+18-13+30-13) MeV Br(B0→Z–K+, Z–→ψ(2S)π–) < 3.1x10-5 @ 95% CL without Z No big contradiction M2(K), (GeV2 ) • Fit B0→ψ(2S)π+K– amplitude by coherent sum of RBW contributions • all known Kπ resonances • all known Kπ resonances+ ψ(2S) resonance Galina Pakhlova, ITEP
Z+1,2→χc1π+ PRD78,072004 (2008) ??? M2(χc1π), (GeV2 ) K*(1680) K*(1780) K*(1430) K*(890) M2(K), (GeV2 ) J1=0, J2=0 two Z’s without Z’s Z1 Z2 • B0→χc1π+K–; χc1 →J/ψγ • Dalitz analysis: fit B0→χc1π+K– amplitude by coherent sum of RBW contributions • known Kπ resonances • K*’s + one (c1 π) resonance • K*’s + two (c1 π) resonances M1= (4051±14+20–41) MeV/c2 Γ1= (82+21–17+47–22) MeV M2= (4248+44–29+180–35) MeV/c2 Γ1= (177+54–39+316–61) MeV • Hypothesis of two Z’sresonances is favored over one Z resonance at 5.7 • Spin of Z1,2 isnot determined: J=0 and J=1 result in comparable fit qualities Cannot be conventional charmonium or hybrid Galina Pakhlova, ITEP
Bottomonia Galina Pakhlova, ITEP
b b Bottomonium • Υ(nS) confirmed, χbJ(1, 2P) observed • ηb(nS), hb(nP) are not observed yet • Among them the ground state ηb(1S) expected 35-100 MeV below Υ(1S) Galina Pakhlova, ITEP
Y(3S)→γηb γISR χbJ 10σ non-peaking background subtracted 120M Y(3S) PRL 100, 06200 (2008) Y(2S)→γηb ηb γISR χbJ 3.5σ non-peaking background subtracted 100M Y(2S) arXiv:0903.1124 Discovery of ηb • Decay modes of ηbare not known • Search for Y(3S), Y(2S)→γηb • withe+e→ Υ(3S),Υ(2S) • Monochromatic line in photon energy spectrum • Problem: peaking backgrounds • Υ(nS) → χbJγsoft, χbJ Υ(nS) →γhard • e+e→ γISRΥ(1S) M(ηb) = (9390.4 ± 3.1) MeV/c2 M(Υ(1S)) - M(ηb) = 69.9 ± 3.1 MeV/c2 Theory ~ 60 MeV/c2 Galina Pakhlova, ITEP
arXiv:0810.3829 7.9fb1 arXiv:0809.4120 Fit to inclusive cross section e+e→hadrons coherent Y(5S) +Y(6S)+continuum 3.9fb1 Y(5S) & Y(6S) Energy scan above Υ(4S) to search for counterpart of Y(4260) in bottomonium sector: study cross section of e+e→Υ(nS)π+π, (n=1, 2, 3) New bottomoniumlike state or anoumalous large Υ(5S) → Υ(nS)ππdecay Both inclusive and exclusive dipion cross-sections are inconsistent with PDG Y(5S) &Y(6S) parameters Galina Pakhlova, ITEP
Conclusion Y(3940) Z(4430) X(3872) Y(3915) Z(3930) Z1 Z2 X(4160) Y(4260) X(3940) X(4360) Y(4660) Y(4350) Y(4350) Y(4140) Galina Pakhlova, ITEP
Hard work have been done by BaBar&Belle teams • Dozens new states have been observed • Not all of them can be presented in a 30’ talk • charmed baryons, light mesons are missed here • PDG almost double its volume after 10 years of BaBar&Belle running • Theorists work also hard, but many states remain unexplained • New Super B-factories could help to resolve most of XYZ puzzles … but likely (hopefully) add more … Galina Pakhlova, ITEP
Thank You Galina Pakhlova, ITEP