A Discovery of the tetraquark by the Belle Experiment
Sookyung Choi (For the Belle Collabora on) Gyeongsang Na onal 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 : Zb’s • More charged charmonium-like states : Zc (3895), … , more BESIII Zc’s
2
Charmonium & Bo omonium spectrum _
3 cc assignments for the XYZ mesons? _ S Olsen, Front. Phys. 10, 101401 (2015)
Z(4430)
no unassigned levels for Y(4360) the (5) charged Zs
- -
the 1 Y(4260) & Y(4360) _ must have a minimal _ Y(4260) Z2(4250) quark content of ccud X(4160) Z(4200)
Z(4050) Close to D*D* threshold
X(3940) Y(3915) Zc(3900) X(3872) Close to D*D threshold
the X(3940) & X(4160) as the Y(3915) mass and the ηc(3S) & ηc(4S) would Γ(Y ωJ/ψ) are too imply huge hyperfine high for the χc0(2P) splittings for n=3&4
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 _ u c Hybrids _ u _ c _ c c
(π)
_ c _ c _ u _ π u _ c _ u c _ u c (π) c meson - molecules diquarkonium hadro - quarkonium (diquark-dian quarks)
Ispin triplet neutral doublet & singlet ? charged doublet X(3872)YZ should have partner states: Three missing states in any pictures 6 The X(3872) BKπ+π-J/ψ
ψ’π+π-J/ψ
X(3872)π+π-J/ψ
X(3872) a er 11 years (& >1000 cites, by 2014 Nov)
7 What do we know about the X(3872)? Belle
BaBar
BESIII
CMS
Y(4260) γX(3872)? MX(3872) = 3871.69 ± 0.17 MeV mD0 + mD*0 = 3871.80 ± 0.17 MeV “B.E.” = 100 ± 210 keV 8 ΓX(3872< 1.2 MeV (90% CL) JPC=1++ Belle PRD 84, 052004(R): JPC = 1++ or 2-+ CDF PRL 98, 132002: JPC = 1++ or 2-+
1-- 1++, 2-+
0++
LHCb PRL 110, 222001: JPC = 1++ Radia ve decays of X(3872) : a probe of the nature of X(3872)
C=+1 X(3872) γ ψ’, γ J/ψ BaBar Belle LHCb
From T. Skwarnicki (Moriond QCD 2015) 10 Strong decay X(3872)DD* PRD81, 031103(2010) B →K D0D*0 2-dim. Fit 605 fb-1 D*0→D0γ 6.4σ B+&D 0BD00 π→0 D0D*0K +0.7 M =3875.1 ±0.5 MeV −0.5 414fb-1 B →KD0D0π0
347fb-1 D*0→D0π0
BaBar PRD77, 011102(2008)
Belle PRL97, 162002(2006)
Both groups saw a high mass value + 0.6 + 0.4 & a Bf(DD*) ≈ 10x Bf(π+π-J/ψ) M = 3872.9 − 0.4 − 0.5 MeV Agrees with Mass from ππJ/ψ mode + 2.8 + 0.2 Γ(BW) = 3.9 − 1.4 − 1.1 MeV
*0 0 -4 B(BK X3872)xB(X3872D D ) = (0.80±0.20± 0.10)x10 11 Isospin of the X(3872)
No X(3872) charged partner states in BKπ+π0J/ψ Belle PRD 84, 052004(R) + + (If M(X ) > mD++mD*0 ≈ 3877 MeV, Γ(X ) may be wide) & BaBar PRD 71, 031501 0
0 - + 0* + 0 + 0 0 D B K π π J/ψ B K π π* J/ψ D +m + +m D + D m m
M(π+π0J/ψ) (GeV) M(π+π0J/ψ) (GeV)
12 Isospin mixing in the X(3872)
X(3872) ρ J/ψ Isospin viola ng decay modes (each other) with similar BFs ω J/ψ
X(3872)D0D*_ 0 ~ 10 x BF(X J/ψππ )
Eric Braaten: “S-wave DD* molecular components must exist” _
D0 D+
D*- _
D* 0
0 _ 0 X(3872) is mostly |D D* > mixture of |I=0 >& |I=1> 13
_ _ CDF: ~85% of pp_ X(3872) is prompt D0: prompt ppX(3872)X ≈ ppψ’X
D0 PRl 93, 162002
prompt
X(3872) & ψ’ have similar produc on characteris cs (i.e. pT- & |y|-dependence, isola on, etc.)
BX(3872)+X _ c D0 c
ψ’ _
D* 0 14 “hybrid” model for the X(3872)
e.g., Takizawa & Takeuchi PTEP 9, 093D01
D0
+ _ D
c
D*- c _
D* 0
XωJ/ψ decays XρJ/ψ decays produc on
15 Charged Charmonium-like states :
Z(4430), Z(4050), Z(4250) , Z(4200) (new) and Z(3885)..
16 The Z(4430)+ Found by Belle in 2007
Belle : 660M BB
S-K Choi et al Belle: PRL 100 142001 R. Mizuk et al Belle: PRD 78 072004
5.2σ
+ M(π ψ’) Not seen by BaBar But both Data seems consistent Charged state cannot be Belle published two more results
Latest one uses 17 4D amplitude analysis Quantum numbers of the Z(4430)+ Z(4430)+ π+ψ’ in BΚ-π+ψ’ K Chilikin et al Belle: PRD 88 07402 (2013)
Belle : 772 M BB
6.1σ
M2(π+ψ’) Results from 4D fit 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 BK+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
BKπ+J/ψ with Z(4430) 4.0σ
no Z(4430)
This may support the Z(4430) as an hadro-charmonium other than conven onal tetraquark state
M(Zc(4430))-M(Zc(3900)) = 589 ± 30 MeV Is Z(4430) a radial excita on of the ground M(ψ’) – M(J/ψ) = 589 MeV 22 state of Zc(3900) ? + + + Z(4050) and Z(4250) π χc1 0 - + in B Κ π χc1 PRD 78, 072004 (2008)
> 5 σ
23 Charged Bo omonium-like Zb states and neutral partner state:
+ + 0 Zb(10610) , Zb(10650) and Zb(10610)
24 The Y(4260)
+ - + - found by BaBar in e e → γISRπ π J/ψ hadrons)
- e + (e σ Confirmed by Cleo, Belle and BES
BaBar PRD86, 051102
Ecm (GeV) → Γ(π+π-J/ψ) is large, 10~100 × charmonium
M(π+π-J/ψ) (GeV) Is there a b-quark version of Y(4260)? 25
26 26 26
Energy scan
ϒ ± keV 110 590 ” (5S) “
ϒ ± keV 0.35 1.75 (4S)
1S 4,5S ϒ ππ Γ ) (Y parent
Belle: PRL 100 112001
3S 2S
“5S” 4S
6 6 × ~ Signal
~1/5
σ
th
~1/20 Lum
th
ϒ ϒ π π (1S) ? (4S,5S)
+
-
and ISR correc on applied)
Is there any anomaly in
(Con nuum subtrac on
ϒ ππ , b (nS)
R R
bo omonium “ ” bb mesons
New Measurement of _ Belle PRL 108, 122001 (2012) “ϒ(5S)” π+π- ϒ (1,2,3S) ? 121.4 -1
+ -
Υ(3S)π π ) + - ± π π π ϒ ( 2 M
Υ(2S)π+π-
) ± π ϒ ( 2 M
+ - π+π- Υ(1S)π π
) ± π ϒ ( 2 M
2 + - M (π π ) 27 + - Belle PRL 108, 122001 (2012) “ϒ(5S)” π π ϒ (1S) ? 121.4 -1
Υ(3S)π+π-
) + - ± π π π ϒ ( 2 M
M(ϒ(3S)π±)
Υ(2S)π+π-
M(ϒ(2S)π±) π+π- Υ(1S)π+π-
± M(ϒ(1S)π ) 28 Belle PRL 108, 122001 (2012) - + 121.4 -1 “ϒ(5S)” π Zb1,2 π+ϒ (1,2,3S)
MeV + MeV π 10,660 10,610
ϒ (3S)
ϒ (2S)
ϒ (1S)
+ M(ϒ(nS)π )max 29 Belle PRL 108, 122001 (2012) “ϒ(5S)” π-Z + 121.4 -1 Bo omonium spectrum b1,2 + π hb(1P, 2P)
MeV + MeV π 10,660 10,610
30 Summary of parameter measurements
Belle PRL 108, 122001 * B +m B* B m 2m
B d b
B* Z (10610) Z (10650) d b b b M=10607.2±2.0 MeV M=10652.2±1.5 MeV Γ=18.4±2.4 MeV Γ=11.5±2.2 MeV
31
_ _
Zb(10610)BB* & Zb(10650)B*B* _
“ϒ(5S)” π-(BB*)+ “ϒ(5S)” π-(B*B*)_ +
± Z (10650)± Zb(10610) b
_ _ M(B*B*)
M(BB*) arXiv : 1209.6450
_
Bf(Zb(10610)BB* _
_ =6.2±0.7 Bf(Zb(10650)B*B* Bf(Z (10610) +(bb) _ =2.8±0.4 b π + Bf(Zb(10650)π (bb)
32 0 0 0 Zb search in ϒ(5S) π π ϒ (1,2S)
Belle PRD 88 052016 (2013)
33 More Zc states
34 Discovery chain from Y(4260) to Zb(c)’s
+ - + - by BaBar in e e → γISRπ π J/ψ Y(4260) discovered
Is there a b-quark equivalent?
??? Yes, & it decays to Zb states + - ϒ(5S) π Ζb π+π- ϒ (1S) Are there c-quark versions of Zb’s?
Yes, many Zc’s !!
35 PRL 110, 252002 (2013) Zc(3895) by Belle arXiv:1304.0121 + - - + + - e e (γ)Y(4260)π Zc(3895) π π J/ψ
Z(4430) Y(4360) BESIII data clearly Y(4260) P + Z2(4250) establish J =1 X(4160) From DD* + π Z(4050)
X(3940) Y(3915) Zc(3900) X(3872)
π-
Mass = (3894.5 ± 6.6 ± 4.5) MeV Neutral XYZ states Width = (63 ± 24 ± 26) MeV Charged Z states Fraction = (29.0 ± 8.9)% (stat. error only) Significance = 5.2 σ 36 - + + Y(4260)π Zc(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 Zc states from BESIII
38 Summary of Zc 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(ηc π π ) (GeV) M(ηc π π ) (GeV)
40 X(3872) and other 1+ XYZ states Molecules Level Diagram ? (By S. Olsen Front. Phys. 10, 101401 (2015)
P + The J =1 bo omonium states? (See above ref.)41 Summary Belle discovered many XYZ states . List of XYZ mesons keeps growing, however, their nature is s ll in a mystery.
Remains opportuni es for LHCb and BelleII. 10 years a er the X(3872)’s discovery, this is the most highly cited B-factory _
paper and BE = ( mD *0_ + mD0) - MX(3872) gets smaller, and now the BE= 0.1 +- 0.2MeV Models for the X(3872)YZ suggest the existence of addi onal 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 conven onal charmonium interpreta on But s ll non-resonant interpreta on ( resca ering) possible. NEW charged state Z(4200) + is observed in BJ/ψ π+ K- decay. The quantum number is 1+. Evidence of the Z(4430)+ π+J/ψ is found. + + 0 Zb(10610) , Zb(10650) and Zb(10610) are the first candidate of ispin triplet in Belle.
Many Zc states are recently discovered from BESIII (Belle) : including two sets of Isospin triplet states Zc(3900) and Zc(4020). 42 Back-up slides
43 …
+ - M = 3872.0±0.6±0.5 MeV X(3872)ρJ/ψπ π J/ψ X(3872) / γχc1
3 C=+ X(3872) ≠ 1 D2 (ψ2) M ≈ m 0+m 0 X(3872) D D* 44 The Belle experiment
TOF counter
Peak luminosity recorded at KEKB: L=2.1 x 1034/cm2/sec with crab cavi es
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 Collabora on) 46 0 + - B →X(3872)K π PRD91, 051101 (R) (2015)
0 + – + – B(B →X(K π )K*+NR) B(X→J/ψπ π ) = (7.9±1.3±0.4) x 10–6
+ 0 – + – (B(B →X(K 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) PRL 112, 222002 (2014)
K* vetoed
4-dim amplitude analysis BKπ+ψ’
48 + Argand plot for Zc(4200)
Clearly shows Resonance-like change Much larger errors and impossible to of the amplitude Draw any conclusion yet.
Unlike LHCb, Belle have two plots for two helicity amplitudes including
higher waves. For S-wave, H1 = H0 49 Belle PRD 82, 091106R (2010) Energy scan to search for anomalous structure Total 29.8 -1
Rϒ(nS)ππ =
Rb =
BaBar PRL 102, 012001 (2009)
10.865 ± 0.008 GeV
+ - Recall Y(4260) with anomalous Γ(J/ψ π π ) ⇒ Is there a ϒb equivalent close to ϒ(5S) 50 _ _ B-B* & B*-B* molecules??
± Z (10610)± B Z (10650) B*
b b b b _
b _ b _ _ B* B* _ _ B-B* “molecule” B*-B* “molecule” M –(M +M ) = + 2.7 ± 2.1 MeV Zb(10610) B B* M –2M = + 2.0 ± 1.8 MeV Zb(10650) B* Slightly unbound threshold resonances??
Belle: M=10607.2±2.0 MeV M=10652.2±1.5 MeV Γ=18.4±2.4 MeV Γ=11.5±2.2 MeV
PDG: MB + MB* = 10604.5±0.6 MeV MB* + MB* = 10650.2 ± 1.0 MeV 51 BESIII collected 5 / 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 0 Zc(3900) ? ( a neutral isospin partner state)
0 Zc(3900)
First hint from
54 0 Search for Zc(3900)
0 Zc(3900)
This establishes the Isospin triplet of Zc(3900) 55