A Discovery of the tetraquark by the Belle Experiment Sookyung Choi (For the Belle Collabora5on) Gyeongsang Na5onal University JAGIELLONIAN Symposium, Krakow, Poland, June 9 2015 1
Outline X(3872) Charged Charmonium- like states : Z(4430), Z(4200), Charged Bo\omonium- like states : Z b s More charged charmonium- like states : Z c (3895),, more BESIII Z c s 2
Charmonium & Bo\omonium spectrum 3
cc assignments for the XYZ mesons? S Olsen, Front. Phys. 10, 101401 (2015) no unassigned levels for the 1 - - Y(4260) & Y(4360) Y(4360) Y(4260) X(4160) Z(4430) Z 2 (4250) Z(4200) the (5) charged Zs must have a minimal quark content of ccud Z(4050) Close to D*D* threshold X(3940) Y(3915) Z c (3900) X(3872) Close to D*D threshold the X(3940) & X(4160) as the η c (3S) & η c (4S) would imply huge hyperfine splittings for n=3&4 the Y(3915) mass and Γ(Y ωj/ψ) are too high for the χ c0 (2P) Neutral XYZ states Charged Z states 4
The list of XYZ states keeps growing (@2014) S Olsen, Front. Phys. 10, 101401 (2015) 5
Models for XYZ Mesons Tetra- quarks Hybrids u c c u c c u c π c u meson - molecules u c u c diquarkonium (diquark- dian5quarks) (π) c c (π) hadro - quarkonium Ispin triplet & singlet? neutral doublet charged doublet X(3872)YZ should have partner states: Three missing states in any pictures 6
The X(3872) B Kπ + π - J/ψ ψ π + π - J/ψ X(3872) π + π - J/ψ X(3872) aher 11 years (& >1000 cites, by 2014 Nov) 7
What do we know about the X(3872)? Belle BaBar BESIII CMS M X(3872) = 3871.69 ± 0.17 MeV m D 0 + m D* 0 = 3871.80 ± 0.17 MeV B.E. = 100 ± 210 kev Γ X(3872 < 1.2 MeV (90% CL) Y(4260) γx(3872)? 8
CDF PRL 98, 132002: J PC = 1 ++ or 2 - + J PC =1 ++ Belle PRD 84, 052004(R): J PC = 1 ++ or 2 - + 1 - - 1 ++, 2 - + 0 ++ LHCb PRL 110, 222001: J PC = 1 ++
Radia5ve decays of X(3872) : a probe of the nature of X(3872) X(3872) γ ψ, γ J/ψ C=+1 BaBar Belle LHCb From T. Skwarnicki (Moriond QCD 2015) 10
Strong decay X(3872) DD* 2- dim. Fit PRD81, 031103(2010) B K D 0 D *0 605 fb -1 6.4σ B + & D0 BD 0 π D 0 0 D *0 K M =3875.1 +0.7 0.5 414fb -1 B KD 0 D 0 π 0 ±0.5 MeV 347fb -1 D *0 D 0 γ D *0 D 0 π 0 BaBar PRD77, 011102(2008) Belle PRL97, 162002(2006) Both groups saw a high mass value & a Bf(DD*) 10x Bf(π + π - J/ψ) M = 3872.9 + 0.6 0.4 + 0.4 0.5 MeV Agrees with Mass from ππj/ψ mode Γ(BW) = 3.9 + 2.8 1.4 + 0.2 1.1 MeV B(B K X 3872 )xb(x 3872 D *0 D 0 ) = (0.80±0.20± 0.10)x10-4 11
Isospin of the X(3872) No X(3872) charged partner states in B Kπ + π 0 J/ψ (If M(X + ) > m D ++m D* 0 3877 MeV, Γ(X + ) may be wide) Belle PRD 84, 052004(R) & BaBar PRD 71, 031501 B 0 K - π + π 0 J/ψ m D ++m D* 0 B + K 0 π + π 0 J/ψ m D ++m D* 0 M(π + π 0 J/ψ) (GeV) M(π + π 0 J/ψ) (GeV) 12
Isospin mixing in the X(3872) X(3872) ρ J/ψ ω J/ψ Isospin viola5ng decay modes (each other) with similar BFs X(3872) D 0 D* 0 ~ 10 x BF(X J/ψππ ) Eric Braaten: S- wave DD* molecular components must exist D 0 D + D* - D* 0 X(3872) is mostly D 0 D* 0 > mixture of I=0 >& I=1> 13
CDF: ~85% of pp X(3872) is prompt D0: prompt pp X(3872)X pp ψ X D0 PRl 93, 162002 prompt X(3872) & ψ have similar produc5on characteris5cs (i.e. p T - & y - dependence, isola5on, etc.) D 0 B X(3872)+X c c ψ D* 0 14
hybrid model for the X(3872) e.g., Takizawa & Takeuchi PTEP 9, 093D01 D 0 D + D* - c c D* 0 X ωj/ψ decays X ρj/ψ decays produc5on 15
Charged Charmonium- like states : Z(4430), Z(4050), Z(4250), Z(4200) (new) and Z(3885).. 16
Belle : 660M BB The Z(4430) + Found by Belle in 2007 S- K Choi et al Belle: PRL 100 142001 R. Mizuk et al Belle: PRD 78 072004 5.2σ M(π + ψ ) Charged state cannot be Not seen by BaBar But both Data seems consistent Belle published two more results Latest one uses 4D amplitude analysis 17
Quantum numbers of the Z(4430) + Z(4430) + π + ψ in B Κ - π + ψ K Chilikin et al Belle: PRD 88 07402 (2013) Belle : 772 M BB 6.1σ Results from 4D fit M 2 (π + ψ ) 4485 MeV 18 1 + is favored over 0 - by 3.4 σ 18
Is Z(4430) + a resonance or resca\ering effect? Taken from T. Skwarnicki (Moriond QCD 2015) LHCb 19
The Z(4200) + New from Belle: 4- dim analysis of B K + π - J/ψ K Chilikin et al Belle: PRD 90 112009 (arxiv: 1408.6457 ) (2014) 20
New state Z(4200) + π - J/ψ 6.2 σ 13 +1 132 +1 1 + is favored over 0 - by 6.1σ and 2 - by 4.4 σ 21
Z(4430) + π - J/ψ B Kπ + J/ψ with Z(4430) 4.0σ no Z(4430) This may support the Z(4430) as an hadro- charmonium other than conven5onal tetraquark state M(Z c (4430))-M(Z c (3900)) = 589 ± 30 MeV M(ψ ) M(J/ψ) = 589 MeV Is Z(4430) a radial excita5on of the ground state of Z c (3900)? 22
Z(4050) + and Z(4250) + π + χ c1 in B 0 Κ - π + χ c1 PRD 78, 072004 (2008) > 5 σ 23
Charged Bo\omonium- like Z b states and neutral partner state: Z b (10610) +, Z b (10650) + and Z b (10610) 0 24
The Y(4260) σ(e + e - hadrons) found by BaBar in e + e - γ ISR π + π - J/ψ Confirmed by Cleo, Belle and BES BaBar PRD86, 051102 Γ(π + π - J/ψ) is large, 10~100 charmonium E cm (GeV) M(π + π - J/ψ) (GeV) Is there a b- quark version of Y(4260)? 25
bo\omonium bb mesons New Measurement of R b, R ϒ(nS)ππ Is there any anomaly in ϒ(4S,5S) π + π - ϒ (1S)? (Con5nuum subtrac5on and ISR correc5on applied) Lum ~1/20 th σ ~1/5 th Signal ~ 6 2S 3S 4S 5S Belle: PRL 100 112001 parent Γ(Y 4,5S ππϒ 1S ) ϒ(4S) ϒ(5S) 1.75 ± 0.35 kev 590 ± 110 kev Energy scan 26
ϒ(5S) π + π - ϒ (1,2,3S)? Belle PRL 108, 122001 (2012) 121.4 c - 1 π + π - M 2 (ϒπ ± ) Υ(3S)π + π - Υ(2S)π + π - M 2 (ϒπ ± ) π + π - Υ(1S)π + π - M 2 (ϒπ ± ) M 2 (π + π - ) 27
ϒ(5S) π + π - ϒ (1S)? Belle PRL 108, 122001 (2012) 121.4 c - 1 Υ(3S)π + π - π + π - M 2 (ϒπ ± ) M(ϒ(3S)π ± ) Υ(2S)π + π - π + π - Υ(1S)π + π - M(ϒ(2S)π ± ) M(ϒ(1S)π ± ) 28
ϒ(5S) π - Z + b1,2 Belle PRL 108, 122001 (2012) 121.4 c - 1 π + ϒ (1,2,3S) π + 10,610 MeV 10,660 MeV ϒ (3S) ϒ (2S) ϒ (1S) M(ϒ(nS)π + ) max 29
Bo\omonium spectrum ϒ(5S) π - Z b1,2 + Belle PRL 108, 122001 (2012) 121.4 c - 1 π + h b (1P, 2P) π + 10,610 MeV 10,660 MeV 30
Summary of parameter measurements m B +m B* 2m B* Belle PRL 108, 122001 B d b B* d b Z b (10610) M=10607.2±2.0 MeV Z b (10650) M=10652.2±1.5 MeV Γ=18.4±2.4 MeV Γ=11.5±2.2 MeV 31
Z b (10610) BB* & Z b (10650) B*B* ϒ(5S) π - (BB*) + ϒ(5S) π - (B*B*) + Z b (10610) ± Z b (10650) ± M(BB*) arxiv : 1209.6450 M(B*B*) Bf(Z b (10610) BB* Bf(Z b (10610) π + (bb) =6.2±0.7 Bf(Z b (10650) B*B* =2.8±0.4 Bf(Z b (10650) π + (bb) 32
Z b 0 search in ϒ(5S) π 0 π 0 ϒ (1,2S) Belle PRD 88 052016 (2013) 33
More Z c states 34
Discovery chain from Y(4260) to Z b(c) s by BaBar in e + e - γ ISR π + π - J/ψ Y(4260) discovered Is there a b- quark equivalent???? Yes, & it decays to Z b states Are there c- quark versions of Z b s? ϒ(5S) π + Ζ b - π + π - ϒ (1S) Yes, many Z c s!! 35
Z c (3895) by Belle e + e - (γ)y(4260) π - Z c (3895) + π + π - J/ψ PRL 110, 252002 (2013) arxiv:1304.0121 Y(4360) Y(4260) X(4160) X(3940) Z(4430) Z 2 (4250) π + Z(4050) Y(3915) Z c (3900) X(3872) BESIII data clearly establish J P =1 + From DD* π - Neutral XYZ states Charged Z states Mass = (3894.5 ± 6.6 ± 4.5) MeV Width = (63 ± 24 ± 26) MeV Fraction = (29.0 ± 8.9)% (stat. error only) Significance = 5.2 σ 36
Y(4260) π - Z c (3900) + π π + J/ψ BESIII: PRL 110, 252001 arxiv:1303.5949 Mass = (3899.0±3.6±4.9) MeV Width = (46±10±20) MeV Fraction = (21.5±3.3±7.5)% Significance > 8 σ 37
Z c states from BESIII 38
Summary of Z c states discovered in the BESIII experiment From Xu Xinping, C. Yuan (QWG2014) 39
Z(3900) 0 & Z(4020) 0 search at Belle From Anna Vinokurova at CHARM2015 arxiv : 1501:06351 JHEP.. M(η c π + π - ) (GeV) M(η c π + π - ) (GeV) 40
X(3872) and other 1 + XYZ states Molecules Level Diagram? (By S. Olsen Front. Phys. 10, 101401 (2015) The J P =1 + bo\omonium states? (See above ref.) 41
Belle discovered many XYZ states. Summary List of XYZ mesons keeps growing, however, their nature is s5ll in a mystery. Remains opportuni5es for LHCb and BelleII. 10 years aher the X(3872) s discovery, this is the most highly cited B- factory paper and BE = (m D* 0+ m D 0) - M X(3872) gets smaller, and now the BE= 0.1 +- 0.2MeV Models for the X(3872)YZ suggest the existence of addi5onal states Z(4430)+ from Belle is confirmed and J P is conclusively 1 +. Argand plot (LHCb) shows resonance behavior Charge and quantum numbers rule out conven5onal charmonium interpreta5on But s5ll non- resonant interpreta5on (resca\ering) possible. NEW charged state Z(4200) + is observed in B J/ψ π + K - decay. The quantum number is 1 +. Evidence of the Z(4430) + π + J/ψ is found. Z b (10610) +, Z b (10650) + and Z b (10610) 0 are the first candidate of ispin triplet in Belle. Many Z c states are recently discovered from BESIII (Belle) : including two sets of Isospin triplet states Z c (3900) and Z c (4020). 42
Back- up slides 43
M = 3872.0±0.6±0.5 MeV X(3872) ρj/ψ π + π - J/ψ X(3872) / γχ c1 M X(3872) m D 0+m D* 0 C=+ X(3872) 1 3 D 2 (ψ 2 ) 44
The Belle experiment TOF counter Peak luminosity recorded at KEKB: L=2.1 x 10 34 /cm 2 /sec with crab caviges 45
QCD hybrid? c c lightest 1 ++ hybrid ~4.4 GeV excited- state hybrids ground- state hybrids charmonium L Liu et al., JHEP 1207, 126 (2012) (Hadron Spectrum Collabora5on) 46
B 0 X(3872)K + π - PRD91, 051101 (R) (2015) B(B 0 X(K + π ) K*+NR ) B(X J/ψπ + π ) = (7.9±1.3±0.4) x 10 6 (B(B + X(K 0 π ) K*+NR ) B(X J/ψπ + π ) = (10.6±3.0±0.9) x 10 6 ) [both K*and (K+π ) NR ] 47
Results by Adding Z + (LHCb) K* vetoed 4- dim amplitude analysis B Kπ + ψ PRL 112, 222002 (2014) 48
Argand plot for Z c (4200) + Clearly shows Resonance-like change of the amplitude Much larger errors and impossible to Draw any conclusion yet. Unlike LHCb, Belle have two plots for two helicity amplitudes including higher waves. For S-wave, H 1 = H 0 49
Belle PRD 82, 091106R (2010) Energy scan to search for anomalous structure R ϒ(nS)ππ = Total 29.8 c - 1 R b = BaBar PRL 102, 012001 (2009) 10.865 ± 0.008 GeV Recall Y(4260) with anomalous Γ(J/ψ π + π - ) Is there a ϒ b equivalent close to ϒ(5S) 50
B- B* & B*- B* molecules?? B Z b (10610) ± Z b (10650) ± b B* b b B- B* molecule B* b B* B*- B* molecule M Zb (10610) (M B +M B* ) = + 2.7 ± 2.1 MeV M Zb (10650) 2M B* = + 2.0 ± 1.8 MeV Slightly unbound threshold resonances?? Belle: M=10607.2±2.0 MeV Γ=18.4±2.4 MeV M=10652.2±1.5 MeV Γ=11.5±2.2 MeV PDG: M B + M B* = 10604.5±0.6 MeV M B* + M B* = 10650.2 ± 1.0 MeV 51
BESIII collected 5 /ƒ above 4GeV for XYZ study BESIII Y(4260) γx(3872) 52
CLEOc data at 4.17 GeV: 1304.3036 M = 3885±5±1 MeV Γ = 34±12±4 MeV 81 ± 20 events 6.1σ 53
Z c (3900) 0? ( a neutral isospin partner state) Z c (3900) 0 First hint from 54
Search for Z c (3900) 0 Z c (3900) 0 This establishes the Isospin triplet of Z c (3900) 55