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Observation of charged bottomonium -like states -and a few other items-. Stephen Lars Olsen Seoul National University. New Frontiers in QCD (QCD-2011) Yonsei University, Seoul Korea, October 27 ~ 28, 2011. Constituent Quark Model. Λ = (uds). Mesons are quark-antiquark pairs.
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Observation of charged bottomonium-like states -and a few other items- Stephen Lars Olsen Seoul National University New Frontiers in QCD (QCD-2011) Yonsei University, Seoul Korea, October 27 ~ 28, 2011
Constituent Quark Model Λ= (uds) Mesons are quark-antiquark pairs Baryons are quark-quark-quark thriplets Fabulously successful Quarks are probably the most well known particle physics quantity among the general public 2
Are there other color-singlet spectroscopies? Pentaquark: H-diBaryon Glueball Tetraquarkmesons qq-gluon hybrid mesons Other possible “white” combinations of quarks & gluons: u d u d s _ u tightly bound 6-quark state d s S=+1 Baryon u s d Color-singlet multi- gluon bound state D0 _ c _ u loosely bound meson-antimeson “molecule” c tightly bound diquark-diantiquark u _ p _ u c _ _ u _ D*0 c _ _ c c
predicted measured Strategy: Search for a meson that decays to a final state containing a c and c quark, If it is a standard qq meson, it has to occupy one of the unfilled states indicated above. If not, it is exotic. unassigned _ _
“XYZ” mesons Zb(10610) 10608 ± 2 15 ± 3 1+p±hb(1,2P),p±Y(1,2,3S) Y5Sp Zb(10610)± Zb(10610) 10653 ± 2 14 ± 3 1+p±hb(1,2P),p±Y(1,2,3S) Y5Sp Zb(10650)±
The X(3872) Study p+p-J/y produced in BK p+p- J/y decays Polarized along flight direction in B rest frame ???? EB=Ecm/2
The X(3872) in BK p+p-J/y discovered by Belle (140/fb) PRL 91, 262001 (2003) y’p+p-J/y X(3872)p+p-J/y M(ppJ/y) – M(J/y)
X(3872)p+p-J/y with all Belle data 3-dimensional fits M(J/ψπ+π-) EB-Ecm/2 MB B+XK+ B0XK0
diquark-diantiquark? diquark-diantiquark (tetra-quark) model Maianieal PRD71, 014028 Expect two neutral states: Predict : DM(Mx(B+)-Mx(B0)) =8±3 MeV Plus charged partners: X+= Xu= X-= Xd= Isospin relations: u d u d c c c c d u u d c c c c
Two neutral states? B+XK+ B0XK0 Maianieal PRD71, 014028 Predict : DM(Mx(B+)-Mx(B0)) =8±3 MeV
charged partners of the X(3872) ? X+(3872)p+p0J/y : Isospintriplet? 2-dim. Fit B0X+K- Nevts =4.2±7.8 B(B0K-X+)xB(X+p+p0J/y)<3.9 x10-6 Rule out isospin triplet model B+X+K0 No signals B(B+K0X+)xB(X+p+p0J/y)<4.5x10-6 not 2x larger!!
X(3872)p+p-J/y Mass recent results LHCb Belle CDF ~6000 evts! MX = 3871.61 ± 0.16 ± 0.19 MeV MX = 3871.96 ± 0.46 ± 0.10 MeV MX = 3871.85 ± 0.27 ± 0.19 MeV
X(3872) mass(in p+p-J/ychannel only) • =3871.79 ± 0.30 MeV _ MX(3872) –(MD0+MD*0)= -0.12 ± 0.35 MeV
D0D*0 molecule? __ _ D0-D*0 “Binding Energy” small Dm = -0.12 ± 0.35 MeV …coincidence?? an “old” idea
De Rujula, Glashow & Georgi (1976) PRL 38, 317 (1976) _ predictions: DD* JPC=1++ _ (DD*)molrJ/y p+p- Also: L. Okun& M. Voloshin JETP Lett. 23, 333 (1974)
p+p-system in X(3872)p+p-J/ycomes from rp+p- Belle: hep-ex/0505038 CDF: PRL 96 102002 rp+p- lineshape M(p+p- ) p+ r p- X3872 J/y M(p+p- )
CDF results on JPC 1++ fits well with no adjustable parameters 2-+ looks like 1++ for some choice of params, at least with current statistics All JPC values other than 1++ or 2-+are ruled out with high confidence CDF: PRL 98 132002 1++ no adj. params 2- +2 adj. params 1- - O++
JPC of the X(3872) Angular distributions for BKX(3872)KrJ/y Partial Wave basis: 775 MeV X(3872)r J/y is right at threshold neglect higher partial waves 3872 MeV 3097 MeV 1++ 2-+ L: S-Wave D-wave S: 1 1,2 L: P-Wave F-wave S: 1,2 1,2 Only 1 amplitude: BLS=B01 1 free parameter: 2 amplitudes: BLS=B11& B12 3 free parameters normalization normalization complex Include relative phase f
JPC of the X(3872) m+ J. Rosner PRD 70, 092023 (2004) qm p+ K c p+ m- c2/dof =1.56/4 c2/dof =4.60/4 1++ fits data well with no free parameters. 2-+ has a free complex parameter; one value gives an acceptable fit c2/dof =0.56/4 c2/dof =5.24/4
_ 1++ cc assignment? cc1 ‘ pinnedto: Mcc2=3930 MeV ‘ • Mass is too low? • 3872 vs 3905 MeV • nr=2 splitting> nr=1 • G(cc1 gy’) ~180 keV • G(cc1 g J/y) ~14 keV • G(cc1 gy’)/G(cc1 g J/y)>>1 • expt’l upper limit: <2.1 ‘ ‘ T.Barneset al PRD 72, 054026 • Gp+p-J/y=(3.4±1.2)GgJ/y ~45 keV huge for Isospin-violating decay c.f.: G(y’p0J/y)≈0.4 keV
X(3872) gy’ ?? Belle 2010: y’ l+l- y’J/yp+p- B+ B+ no signals!! M(gy’) M(gy’) B0 B0 B(B+K+ X3872)xB(X3872gy’) B(B+K+ X3872)xB(X3872gJ/y) < 2.1 (90%)
_ 2-+ cc assignment? hc2 pinned to: My”=3770 MeV • Mass is too high?: • 3872 vs 3837 MeV • G(hc2 gy’) ~0.4 keV • G(hc2 g J/y) ~9 keV • G(hc2 gy’)/G(hc2 g J/y)<<1 Y. Jiaet al arXiv:0107.4541 • Gp+p- J/y=(3.4±1.2)GgJ/y ~30 keV • huge for Isospin-violating decay • c.f.: G(y’p0J/y)≈0.4 keV • BKhc2 violates factorization • BKhc not seen • BKcc2 barely seen _ • hc2 DD* expected to be tiny • Belle & BaBar:: • G(XDD*)/G(Xp+p-J/y)=9.5±3.1 Y. Kalasnikovaet al arXiv:1008.2895 hc2ghc(1S) & pphcmodes expected to dominate _
Belle (May 2010): B+ K+ g J/y calibration reaction 3.6s B+K+cc2: 1st evidence cc1gJ/y M(gJ/y) M(gJ/y) Bf(B+K+cc1)=(49±3)x10-5 Bf(B+K+cc2)=(1.11±0.37)x10-5 B(B+K+cc2) B(B+K+cc1) = 0.022 ±0.007 factorization suppression penalty Belle: arXiv 1105.0177
Narrow width: G<1.2 MeV G= ~ 0.0 best fit below experimental resolution at G = 0.95MeV 90 % inflate by +0.23 MeV for possible biases G<1.2 MeV @ 90% CL Belle prev: G<2.3 MeV
B0→X(3872)K+p- (B→X(3872) K*?) 605 /fb Belle arXiv:0809.1224(2008) 5σ sideband bkgd non-resonant Kπ X(3872)→J/ψπ+π– K*0→Kπ Nsig= 9019 (Nsig=8.2 10.0) Mass(Kπ) No K*Kp signal!! +1.1 - 1.4 B(B0→X(K+π–)non_res) x B(X→J/ψπ+π–) = (8.1±2.0 )x10–6 dominant ! B(B0→XK*0) x B(X→J/ψπ+π–) < 3.4x10–6 @90% CL small !!
BKX(3872) is very different from other BKCharmonium KX(3872) all K* comes from sideband Belle arXiv:0809.0124 M(K) / GeV Kc1 K′ KJ/ BaBar, Phys. Rev. D71(2005)032005 Belle, Phys. Lett. B634(2006)155 Belle arXiv:0809.0124 M(K) M(K) M(K) K* dominates
X(3872)D0D*0 is observed B KD0D*0 D*0→D0γ 605 fb-1 2-dim. Fits + 0.4 − 0.5 + 0.6 − 0.4 M = 3872.9 MeV D*0→D0π0 Agrees with M from ppJ/y mode + 2.8 − 1.4 + 0.2 − 1.1 G(BW) = 3.9 MeV _ Bf(BK X3872)xBf(X3872D*0D0) = (0.80±0.20± 0.10)x10-4 = (9.5±3.1)x Bf(p+p-J/y) PRD81, 031103(2010) See also: BaBarPRD77, 011102(2008) & Belle PRL97, 162002(2006)
Molecular Picture If the X couples to D0 D*0 in an S-wave: ~ 10 fermis!! E. Braaten, J. Stapleton PRD81, 0140189
X(3872)-J/y relative sizes drms(208Pb nucleus)≈5.5 fm + + drms(J/y) ≈ 0.4 fm + + + 208Pb + + + J/y + + + + + drms(X3872) ~ 5 fm + + + + + + X(3872) Volume(J/y) Volume(X3872) ≈ 10-3 _ • Overlap of the cc necessary to form the J/y in X p+p-J/y decays is rare • How can such a fragile object be produced in H.E. pp collisions? heavy ion collisions?? _ -- arXiv 0906.0882: sCDF(meas)>3.1±0.7nb vsstheory(molecule)<0.11nb C. Bignaminiet al, PRL 103, 162001:
X(3872) as a probe for Heavy Ion physics? _ • Size is huge (but it is produced in pp collisions) • 4 valance quarks unique probe for quark number scaling
JPC = 1- - Y(4260) meson Zb(10610) 10608 ± 2 15 ± 3 1+p±hb(1,2P),p±Y(1,2,3S) Y5Sp Zb(10610)± Zb(10610) 10653 ± 2 14 ± 3 1+p±hb(1,2P),p±Y(1,2,3S) Y5Sp Zb(10650)±
Radiative return B-factory energies g ss cc bb 3~5 GeV 10.58 GeV Ecm(GeV)
233 fb-1 e+e- gisr Y(4260) at BaBar p+p- J/y BaBar PRL95, 142001 (2005) fitted values: M=4259 8 +2 MeV G = 88 23 +6 MeV -6 -9 Y(4260) ~50pb
Y(4260) confirmed by Belle BaBar values: M=4247 12 +17 MeV G = 108 19 ±10 MeV -32 M=4259 8 +2 MeV G = 88 23 +6 MeV -6 -9 C.Z Yuan et al (Belle) PRL 99, 182004
Not seen in e+e- hadrons J.Z.Bai et al (BES), PRL 88, 101802 (2006) s(e+e- hadrons) s(e+e- m+m-) _ No sign of Y(4260)D(*)D(*) 4260 speak(Y(4260)+p-J/)~50 pb Huge by charmonium standards ~3nb BES data G(Y4260p+p- J/y) > 1.0 MeV@ 90% CL X.H. Mo et al, PL B640, 182 (2006)
DD DDπ D*D* DD* DD*π DsDs +DsDs* +Ds*Ds* ΛcΛc Exclusive cross sections contribution to the total cross section Contributions ofD+D*–,D*+D*–, D0D–π+ and D0D*–π+ are scaled following isospin symmetry
peaks in e+e- gISR p+p-y’ e+e-gISRp+p-y’ BaBar M=4324 24 MeV G = 172 33 MeV M(p+p-y’) Peak is 4324 MeV, distinct from 4260 MeV
4325 MeV p+p-y’ peak also seen Two peaks! (both relatively narrow) (& neither consistent with 4260 MeV) X.L. Wang et al (Belle) PRL 99, 142002 (2007) M=4361 9 ±9 MeV G = 74 15 ±10 MeV M=4664 11 ±5 MeV G = 48 15 ±3 MeV 4260 BaBar values M=4324 24 MeV G = 172 33 MeV 548 fb-1
At least three peaks for only one unassigned 1- - level 4664MeV 33D1 4361MeV 4260MeV _ If these are mesons, they must be more complex than simply cc
Zb mesons Zb(10610) 10608 ± 2 15 ± 3 1+p±hb(1,2P),p±Y(1,2,3S) Y5Sp Zb(10610)± Zb(10610) 10653 ± 2 14 ± 3 1+p±hb(1,2P),p±Y(1,2,3S) Y5Sp Zb(10650)±
XYZ counterparts with b-quarks? What about here? W.S. Hou PRD 74, 017504 (2006)
_ “bottomonium” bb mesons 2MB = 10358.7 MeV (4S) p+p- (1S) ?
Belle: G(4S)p+p-(1S) (4S) (1S) p+p- 2S 3S 4S 477 fb-1 52±10 evts
(5S) p+p- (1S) ? 2MB = 10358.7 MeV
Belle:G(5S)p+p-(1S) ~1/20th the data ~1/5ththe cross-section 23.6 fb-1 vs477 fb-1 325±20 evts! >6 times as many events! K.F. Chen et al (Belle) PRL 100, 112001 (2008)
“(5S)” is very different from other states Anomalous production of (nS)+- (MeV) Belle PRL100,112001(2008) X10--2 Recall Y(4260) with anomalous (J/+-) Is there a Yb equivalent close to (5S)
Comparison of s(e+e-p+p-) vss(e+e- hadrons) (5S)p+p- (5S)hadrons ~2s discrepancies in the peak mass and width 5S: Belle PRD82,091106R(2010) Nature of (5S) is puzzling and not yet understood
Look at p+p-recoil mass in (5S)+-+ X 121.4 fb-1 hb(1P) X=(1S) (2S) hb(2P) (3S) MM(+-) spectrum hb(1,2P)JPC=1+- 1st observations MM(+-) residuals
MM(0) hb(1,2P) _ (bb) : S=0 L=1 JPC=1+- Expected mass (Mb0 + 3 Mb1 + 5 Mb2) / 9 MHF test of hyperfine interaction Deviations from CoG of bJmasses hb(1P)(1.6 1.5) MeV/c2 hb(2P)(0.5 +1.6 ) MeV/c2 -1.2 Agrees with expectations Previous search BaBar 3.0 (3S) → 0 hb(1P) arXiv:1102.4565