1

Bottomonium and bottomonium–like states

Alex BondarOn behalf of Belle Collaboration

Cracow Epiphany Conference “Present and Future B-physics”(9 - 11, January, 2012, Cracow, Poland )

2

Observation of hb(1P) and hb(2P)

Outline

(5S) Zb(10610)+ -

Zb(10650)+ -

(1S)+ -

(2S)+ -

(3S)+ -

hb(1P)+ - b(1S) + -

hb(2P)+ -

arXiv:1103.3419accepted by PRL

at BB* and B*B* thresholds molecules

Observation of Zb

arXiv:1105.4583

final state w/ hb(nP) and (nS)

angular analysis

accepted by PRL

Observation of hb(1P) b(1S) arXiv:1110.3934

arXiv:1110.2251

3

PRL100,112001(2008) (MeV)

102

PRD82,091106R(2010)Anomalous production of (nS) +-

1. Rescattering (5S)BB(nS)?Simonov JETP Lett 87,147(2008)

2. Similar effect in charmonium?

shapes of Rb and () different (2)

to distinguish energy scan

(5S)

line shape

of Yb

Y(4260) with anomalous (J/ +-)

assume Yb close to (5S)

4

hb(1P) & hb(2P)

Observation of

5

Trigger

Y(4260)Yb search for hb(nP)+- @ (5S)

CLEO observed e+e- → hc +– @ ECM=4170MeV

PRL107, 041803 (2011)

(hc +–) (J/ +–)

4260

Hint of rise in (hc+-)

@ Y(4260) ?

Y(4260)

6MM(+-)

Introduction to hb(nP)

(bb) : S=0 L=1 JPC=1+

MHF test of hyperfine interaction

For hc MHF = 0.00 0.15 MeV,

expect smaller deviation for hb(nP)

_

Expected mass (Mb0 + 3 Mb1 + 5 Mb2) / 9

(3S) → 0 hb(1P)

BaBar

3.0

arXiv:1102.4565PRD 84, 091101

Previous search

7MM(+-)

Introduction to hb(nP)

(bb) : S=0 L=1 JPC=1+

MHF test of hyperfine interaction

For hc MHF = 0.00 0.15 MeV,

expect smaller deviation for hb(nP)

_

Expected mass (Mb0 + 3 Mb1 + 5 Mb2) / 9

(3S) → 0 hb(1P)

BaBar

3.0

arXiv:1102.4565PRD 84, 091101

Previous search

8

(5S) hb +- reconstructionhb → ggg, b (→ gg) no good exclusive final states

reconstructed

“Missing mass” M(hb) = (Ec.m. – E+-)2 – p+-

* *2 Mmiss(+-)

(1S) (2S) (3S)hb(2P)hb(1P)

9

Results 121.4 fb-1

hb(1P) 5.5

hb(2P) 11.2

Significance w/ systematics

10

Hyperfine splitting

hb(1P) (1.7 1.5) MeV/c2

hb(2P) (0.5 +1.6 ) MeV/c2-1.2

Deviations from CoG (Center of Gravity) of bJ masses

consistent with zero, as expected

Ratio of production rates

Mechanism of (5S) hb(nP) +- decay violates

Heavy Quark Spin Symmetry

for hb(1P)

for hb(2P)no spin-flip

=

spin-flip

Process with spin-flip of heavy quark is not suppressed

11

Resonant structure of

(5S)hb(nP) +-

12

Resonant structure of (5S) hb(1P) +-M

(hb–

), G

eV/c

2

phase-space MC

M(hb+), GeV/c2

13

Resonant structure of (5S) hb(1P) +-

Results

MeV2 = non-res.~0

Fit function

~BB* threshold_

~B*B* threshold__1 = MeV

MeV/c2M2 =

M1 = MeV/c2

a =

= degrees

Significance(16 w/ syst)18

121.4 fb-1

M(h

b–

), G

eV/c

2

phase-space MC

M(hb+), GeV/c2

fit Mmiss(+–)

in M(hb) bins

M(hb), GeV/c2

h b(1

P)

yiel

d /

10M

eV

Zb(10610), Zb(10650)

1414

Resonant structure of (5S) hb(2P) +-

Significances(5.6 w/ syst)6.7

M(h

b–

), G

eV/c

2

phase-space MC

M(hb+), GeV/c2

fit Mmiss(+–)

in M(hb) bins

121.4 fb-1

M(hb), GeV/c2

h b(1

P)

yiel

d /

10M

eV

non-res.~0

hb(1P)+- hb(2P)+-

non-res. set to zero

degrees

MeV/c2

MeV/c2

MeV

c o

n s

i s t

e n

t

MeV2 =

1 = MeV

MeV/c2M2 =

M1 = MeV/c2

a =

= degrees

MeV

15

Resonant structure of

(5S)(nS) +-

(n=1,2,3)

16

(5S) (nS) +-

+-(n = 1,2,3)

(1S)

(2S)

(3S)

reflections

Mmiss (+-), GeV/c2

17

(1S)

(2S)

(3S)

(5S) (nS) +- (n = 1,2,3)

Mmiss (+-), GeV/c2

purity 92 – 94% +-

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(5S) (nS) +- Dalitz plots

(1S) (2S) (3S)

19

(5S) (nS) +- Dalitz plots

(1S) (2S) (3S)

Signals of Zb(10610) and Zb(10650)

20

heavy quark spin-flip amplitude is suppressed

Fitting the Dalitz plots

Signal amplitude parameterization:

S(s1,s2) = A(Zb1) + A(Zb2) + A(f0(980)) + A(f2(1275)) + ANR

ANR = C1 + C2∙m2(ππ)

Parameterization of the non-resonant amplitude is discussed in [1] M.B. Voloshin, Prog. Part. Nucl. Phys. 61:455, 2008.

[2] M.B. Voloshin, Phys. Rev. D74:054022, 2006.

A(Zb1) + A(Zb2) + A(f2(1275))

A(f0(980))

– Breit-Wigner

– Flatte

(5S) Zb, Zb (nS) – no spin orientation changeS-waveS-wave

Spins of (5S) and (nS) can be ignored

Angular analysis favors JP=1+

Non-resonant

2121

Results: (1S)π+π-

M((1 S)π+), GeV M((1S)π-), GeV

signals

reflections

22

Results: (2S)π+π-

reflections

signals

M((2S)π+), GeV M((2S)π-), GeV

23

Results: (3S)π+π-

M((3S)π+), GeV M((3S)π-), GeV

24

M1 = 10607.22.0 MeV

1 = 18.42.4 MeV

M2 = 10652.21.5 MeV

2 = 11.5 2.2 MeV

Summary of Zb parameters

Average over 5 channels

25

M1 = 10607.22.0 MeV

1 = 18.42.4 MeV

M2 = 10652.21.5 MeV

2 = 11.5 2.2 MeV

Zb(10610) yield ~ Zb(10650) yield in every channel

Relative phases: 0o for and 180o for hb

Summary of Zb parameters

Average over 5 channels

M(hb), GeV/c2

h b(1

P)

yiel

d /

10M

eV

= 180o = 0o

26

Angular analysis

27

Angular analysis

Example : (5S) Zb+(10610) - [(2S)+] -

(0 is forbidden by parity conservation)Color coding: JP= 1+ 1- 2+ 2-

Best discrimination: cos2 for 1- (3.6) and 2- (2.7);

non-resonant combinatorialcos1 cos2 rad

cos1 for 2+ (4.3)

i (i,e+), [plane(1,e+), plane(1, 2)]Definition of angles

28

Summary of angular analysis

All angular distributions are consistent with JP=1+

for Zb(10610) & Zb(10650).

All other JP with J2 are disfavored at typically 3 level.

Probabilities at which different JP hypotheses are disfavored compared to 1+

procedure to deal with non-resonant contribution is approximate,no mutual cross-feed of Zb’s

Preliminary:

29

Heavy quark structure in Zb

Wave func. at large distance – B(*)B*

A.B.,A.Garmash,A.Milstein,R.Mizuk,M.Voloshin PRD84 054010 (arXiv:1105.4473)

• Why hb is unsuppressed relative to • Relative phase ~0 for and ~1800 for hb

• Production rates of Zb(10610) and Zb(10650) are similar

• Widths –”–

• Existence of other similar states

Explains

Predicts

0110

0110

2

1

2

12

1

2

1'

QqbbQqbbb

QqbbQqbbb

Z

Z

Other Possible Explanations

• Coupled channel resonances (I.V.Danilkin et al, arXiv:1106.1552)• Cusp (D.Bugg Europhys.Lett.96 (2011),arXiv:1105.5492)• Tetraquark (M.Karliner, H.Lipkin, arXiv:0802.0649)

30

Observation of

hb(1P)b(1S)

31

Introduction to b

Godfrey & Rosner, PRD66 014012 (2002)

hb(1P) → ggg (57%), b(1S) (41%), gg (2%)

hb(2P) → ggg (63%), b(1S) (13%), b(2S) (19%), gg (2%)

Expected decays of hb

Large hb(mP) samples give opportunity to study b(nS) states.

Experimental status of b

M[b(1S)] = 9390.9 2.8 MeV (BaBar + CLEO)

M[(1S)] – M[b(1S)] = 69.3 2.8 MeV

Width of b(1S): no information

pNRQCD: 4114 MeV Lattice: 608 MeVKniehl et al., PRL92,242001(2004) Meinel, PRD82,114502(2010)

(3S) b(1S)

32

Method

reconstruct

b(mS)

(5S) Zb -+

hb (nP) +

Decay chain

Use missing massto identify signals

M(b)

M(hb)

true +-

fake

fake +-

true

true +-

true

MC simulation

33

Method

reconstruct

b(mS)

(5S) Zb -+

hb (nP) +

Decay chain

Use missing massto identify signals

M(b)

M(hb)

true +-

fake

fake +-

true

true +-

true

MC simulation

Mmiss(+- )

Mmiss(+-) – Mmiss(

+-) + M[hb]

34

Method

reconstruct

b(mS)

(5S) Zb -+

hb (nP) +

Decay chain

Use missing massto identify signals

M(b)

M(hb)

MC simulation

Mmiss(+- )

Mmiss(+-) – Mmiss(

+-) + M[hb]

Approach:fit Mmiss(

+-) spectra

in Mmiss(+-) bins

hb(1P) yield vs. Mmiss(+-)

search for b(1S) signal

35

Results

b(1S)

13

potential models : = 5 – 20 MeV

Godfrey & Rosner : BF = 41%

BaBar (3S) b(1S)

BaBar (2S)

CLEO (3S)

BELLE preliminary

pNRQCD Lattice

N.Brambilla et al., Eur.Phys.J.C71(2011) 1534 (arXiv:1010.5827)

MHF [b(1S)] = 59.3 1.9 +2.4 MeV/c2–1.4

36

Observation of two charged bottomonium-like resonances in 5 final states

M = 10607.2 2.0 MeV = 18.4 2.4 MeV

M = 10652.2 1.5 MeV = 11.5 2.2 MeV

First observation of hb(1P) and hb(2P)

Hyperfine splitting consistent with zero, as expectedAnomalous production rates

arXiv:1103.3419accepted by PRL

arXiv:1105.4583,

arXiv:1110.2251,accepted by PRL

Summary

(1S)π+, (2S) π+, (3S)π+, hb(1P)+, hb(2P)+

Angular analyses favour JP = 1+ , decay pattern IG = 1+Masses are close to BB* and B*B* thresholds – molecule?

Observation of hb(1P)b(1S)The most precise single meas., significantly different from WA,decreases tension w/ theory

Will Zb’s become a key to understanding of all other quarkonium-like states?

arXiv:1110.3934

Zb(10610) Zb(10610)

37

Back up

38

(5S)

(6S)

(?S)

IG(JP)

B*B*

BB*

BB

0-(1+) 1+(1+) 0+(0+) 1-(0+) 0+(1+) 1-(1+) 0+(2+) 1-(2+)

12GeV

11.5GeV

Zb Wb0Wb1 Wb2

hbb

b

b

b

0110

0110

2

1

2

12

1

2

1'

QqbbQqbbb

QqbbQqbbb

Z

Z

1100

1100

2

3

2

1

2

1

2

3

0

'0

QqbbQqbbb

QqbbQqbbb

W

W

22

1'1

)(

)(

1111

JQqbbb

JQqbbb

W

W

arXiv:1105.5829

Xb

0-(1-)

390110

0110

2

1

2

12

1

2

1'

QqbbQqbbb

QqbbQqbbb

Z

Z

1100

1100

2

3

2

1

2

1

2

3

0

'0

QqbbQqbbb

QqbbQqbbb

W

W

40

Coupled channel resonance?I.V.Danilkin, V.D.Orlovsky, Yu.Simonov arXiv:1106.1552

No interaction between B(*)B* or is needed to form resonance

No other resonances predicted

B(*)B* interaction switched on individual mass in every channel?

41

Cusp?D.Bugg Europhys.Lett.96 (2011) (arXiv:1105.5492)

Amplitude Line-shape

Not a resonance

42

Tetraquark?

M ~ 10.5 – 10.8 GeV Tao Guo, Lu Cao, Ming-Zhen Zhou, Hong Chen, (1106.2284)

M ~ 10.2 – 10.3 GeVYing Cui, Xiao-lin Chen, Wei-Zhen Deng, Shi-Lin Zhu, High Energy Phys.Nucl.Phys.31:7-13, 2007(hep-ph/0607226)

M ~ 9.4, 11 GeV M.Karliner, H.Lipkin, (0802.0649)

43

Selection

Require intermediate Zb : 10.59 < MM() < 10.67 GeV

Zb

Hadronic event selection; continuum suppression using event shape; 0 veto.R2<0.3

reconstruct

b(mS)

(5S) Zb -+

hb (nP) +

Decay chain

bg. suppression 5.2

44

Mmiss(+-) spectrum

requirement of intermediate Zb

Update of M [hb(1P)] :

Previous Belle meas.:hb(1P)

3S

1S

(2S)

MHF [hb(1P)] = (+0.8 1.1)MeV/c2

MHF [hb(1P)] = (+1.6 1.5)MeV/c2

arXiv:1103.3411

45

Results of fits to Mmiss(+-) spectra

no significant structures

b(1S)hb(1P) yield

Reflection yield

(2S) yield

Peaking background?MC simulation none.

46

Calibration

B+ c1 K+ (J/ ) K+Use decays

match energy of signal & callibration channelscosHel (c1)> – 0.2

hb(1P) b(1S)

cosHel > – 0.2

MC simulation

c1 J/

Photon energy spectrum

47

Calibration (2)

data

Correction of MC

E s.b. subtracted

fudge-factorfor resolution

M(J/), GeV/c2

–0.4mass shift –0.7 0.3 +0.2 MeV

1.15 0.06 0.06

Resolution: double-sided CrystalBall function with asymmetric core

48

Bs

Integrated Luminosity at B-factories

> 1 ab-1

On resonance:(5S): 121 fb-1

(4S): 711 fb-1

(3S): 3 fb-1

(2S): 24 fb-1

(1S): 6 fb-1

Off reson./scan : ~100 fb-1

530 fb-1

On resonance:(4S): 433 fb-1

(3S): 30 fb-1

(2S): 14 fb-1

Off reson./scan : ~54 fb-1

(fb-1) asymmetric e+e- collisions

49

(5S)

Belle took data atE=10867 1 MэВ

2M(Bs)

BaBar PRL 102, 012001 (2009)

(6S)(4S)

e+e- hadronic cross-section

main motivationfor taking data at (5S)

(1S)

(2S)(3S)

(4S)

2M(B)

e+ e- ->(4S) -> BB, where B is B+ or B0

e+ e- -> bb ((5S)) -> B(*)B(*), B(*)B(*), BB, Bs(*)Bs

(*), (1S) , X …

_

_ _ _ __

50

Residuals(1S)

Example of fit

Description of fit to MM(+-)Three fit regions

1 2 3

Ks generic

(3S)

kinematicboundary

MM(+-)

M(

+-

)

MM(+-)

BG: Chebyshev polynomial, 6th or 7th order Signal: shape is fixed from +-+- data“Residuals” – subtract polynomial from data points

KS contribution: subtract bin-by-bin

Results: Y(5S)→Y(2S)Y(5S)→Y(2S)ππ++ππ--

51

Results: Y(5S)→Y(2S)Y(5S)→Y(2S)ππ++ππ--

52