Heavy Quarkonium Roman Mizuk, ITEP RAS session at ITEP, 24 Nov 2009.

transcript

Heavy Quarkonium

Roman Mizuk, ITEP

RAS session at ITEP, 24 Nov 2009

n(2S+1)LJ

n radial quantum number

J = S + LP = (–1)L+1 parity

C = (–1)L+S charge conj.

Charmonium LevelsM

(2S+1)LJ

Open charm threshold (3770)

(4040)

(4160)

(4415)

(potential Models)

c2 c1 c0hchc

(2S+1)LJ

Open charm threshold (3770)

(4040)

(4160)

(4415)

Y(4140)

(potential Models)

c2 c1 c0hchc

n(2S+1)LJ

n radial quantum number

J = S + LP = (–1)L+1 parity

C = (–1)L+S charge conj.

Charmonium Levels

10 XYZ states

XYZ States

Outline

Charmonium

X(3872)

1- - states from ISR

3940 family

BottomoniumObservation of b

Search for Yb

Most of the XYZ from B-factories

+ BES, CDF, D0

e+e– → (4S)Ecms ~ 10.6 GeV

950 + 530 fb-1 in total

6th anniversary!

Phys.Rev.Lett.91 262001, (2003)

Belle citation count

B→Xsγ

X(3872)

PRL91,262001 (2003)

X(3872) was observed by Belle in

B+ → K+ X(3872)′

→ J/ψ π+ π-

recent signals X(3872) → J/ψ π+ π-

X(3872)

Confirmed by CDF, D0 and BaBar.

pp collisions

PRL93,162002(2004)

arXiv:0809.1224 PRD 77,111101 (2008)

PRL103,152001(2009)

Mass & Width

M = 3871.55 0.20 MeV Γ < 2.3 MeV (90% C.L.)

Close to D*0D0 threshold:m = – 0.25 0.40 MeV.

Branching Fractions

Br(X J/ + -) > 2.5%

at 90%C.L.

Absolute Br? missing mass technique

PRL96,052002(2006)

reconstructonly

K+ momentum in B+ c.m.s.

Br(B+ X K+) < 3.210–4

Br(B+ X K+) Br(X J/ + -) =(8.10 0.92 0.66) 10-6

(8.4 1.5 0.7) 10-6

Radiative Decays & J/

CX(3872) = +

X(3872) → J/ + - 0

subthreshold production of

hep-ex/0505037 PRL102,132001(2009)

Decay modes Br relative to J/+-

J/ 0.15 0.05

J/ 0.33 0.12

1.1 0.4

J/ 1.0 0.5

′ J/

CX(3872) = + C+- = – 1. Isospin (+-) = 12. L(+-) = 1

IJPC of 0

PRL96,102002(2006)

hep-ex/0505038

M (+-)

X(3872) → J/+- X(3872) → J/0

X(3872) → J/+-

M (+-) is well described by 0→+- (CDF: + small interfering →+- ).

Angular analyses by Belle and CDF excluded JP =

JPC = 1++ or 2–+

2–+ is disfavored by

JP = 1++ are favorite quantum numbers for X(3872).

0++, 0+-, 0-+,1-+ ,1+-, 1--, 2++, 2-- , 2+-,3--, 3+-

Spin & Parity

2–+ not excluded.

PRL98,132002(2007)

1. Br(X → ′ γ) / Br(X → J/γ) ~ 3 multipole suppression2. Observation of D*0D0 decay centrifugal barrier at the threshold

PRL 97,162002(2006)

B K D0D00

X(3875) X(3872)?

B+& B0 D0D*0K4.9σ

347fb-1

PRD77,011102(2008)

B K D0D*0

605 fb-1

D*→Dγ

D*→D0π0

Flatte vs BW similar result: 8.8σ

arXiv:0810.0358

New Belle vs. BaBar only ~2σ difference

3871.55 ± 0.2

X(3872) Experimental Summary

JPC = 1++ (2–+ not excluded)

Close to D*0D0 threshold: m = – 0.25 0.40 MeV.

Br(X(3872) J/ 0) > 2.5% (90% C.L.)

M = 3871.55 0.20 MeV , Γ < 2.3 MeV (90% C.L.)

Decay modes Br relative to J/ 0

J/ 0 1

J/ 1.0 0.5

J/ 0.17 0.05

1.1 0.4

D*0D0 ~10

JPC = 1++ c1′

X(3872) is not conventional charmonium.

Is there cc assignment for X(3872)?

JPC = 2–+ η c2

Expected to decay into light hadronsrather than into isospin violating mode.

Br( c1′ → J/ )Br( c1′ → J/ +-)

measure 0.170.05

expect 30

~100 MeV lighter than expected

[cq][cq]

Tetraquark?Maiani, Polosa, Riquer, Piccini; Ebert, Faustov, Galkin; …

No evidence for X–(3872) J/ –0 excludes isovector hypothesis

X(3872)–

M(J/π–π0) M(J/π–π0)

X(3872)–

PRD71,031501,2005

PRD71,014028(2005)

1. Charged partners of X(3872).2. Two neutral states ∆M = 8 3 MeV,

one populate B+ decay, the other B0.

Predictions:

Charged partner of X(3872)?

X(3872) Production in B0 vs. B+

No evidence for neutral partner of X(3872) in B0 decays.

B0→XK0s

arXiv:0809.1224 605 fb-1

PRD 77,111101 (2008) [413 fb-1]

MX = (2.7 ± 1.6 ± 0.4) MeV

Two overlapping peaks in J/ +- mode?

No evidence for two peaks m < 3.2 MeV at 90% C.L.

Tetraquarks are not supported by any experimental evidence for existence of X(3872) charged or neutral partners.

PRL103,152001(2009)

D*0D0 molecule?

MX = 3871.55 0.20 MeV(MD*0 + MD0) = 3871.80 0.35 MeV

Weakly bound S-wave D*0D0 system

Swanson, Close, Page; Voloshin; Kalashnikova, Nefediev; Braaten; Simonov, Danilkin ...

Bound state

J/+-D0D00

Virtual state

m = – 0.25 0.40 MeV

a few fm

Predict different line shapes for J/+- and D*0D0 modes:

D0D*0 molecule

Kalashnikova, Nefediev arXiv:0907.4901

Analysis of dataBound or virtual?c1 admixture?

~2 experimental difference reverses conclusion

Present statistics are insufficient to constrain theory?

Br(X(3872) J/ )Br(X(3872) J/ ) ~1

Large isospin violation due to 8 MeV differencebetween D*+D- and D*0D0 thresholds.

Br(X(3872) )Br(X(3872) J/ ) ~3

Similar ratio is expected for c1 decays c1 admixture?

State c1 admixture

Belle data bound ~ 30%

BaBar data virtual ~ 0

Large production rate in B decays and in pp c1 ?

theorists here should agree on the proper form & thenexperimenters should use it in a proper unbinned fit

There are other similar analyses which differ in the fit functions:

Braaten, StapletonZhang, Meng, Zheng

arXiv: 0907.31670901.1553

Br(B0 →XK*0) Br(X→J/ψπ+π–) < 3.4 10–6 at 90% C.L.

~90 events

Very weak K

*(892)

Br(BJ/ K*0)

Br(BJ/ KNR)~4

B → X(3872) K

arXiv:0809.1224 605 fb-1

X(3872) sideband

non-resonant Kπ

Mass(Kπ)

Br(B0 →X(K+π–)non_res) Br(X→J/ψπ+π–) = (8.1±2.0+1.1–1.4) 10–6

DD* molecular models for the X(3872) attribute its production& decays charmonium to an admixture of c1′ in the wave fcn.

But BKX(3872) is very different from BK charmonium.

BaBar PRD 71 032005

Belle arXiv 0809.0124

Belle PRD 74 072004

Belle F.Fang Thesis

KX3872

e+e– → 1–– final states via ISR

s=E2cm-2EEcm

1– –

ISR physics at B-factories Continuous ISR spectrum: access to the whole s interval em suppression compensated by huge luminosity

comparable sensitivity to energy scanning (CLEOc, BES)

Initial State Radiation

e+e– → γISR J/+– Y(4260), Y(4008)?

PRL 95 ,142001(2005)

233 fb-1

PRD74, 091104R (2006)

13.3 fb-15.4σ

PRL 96, 162003 (2006)

11σ(2S)

PRL 99, 182004 (2007)

550 fb-1

Y(4260)

Y(4008)7.4

Y(4260)

One or two states in e+e– → γISR J/+–?PRL 99, 182004 (2007)

550 fb-1

454 fb-1

preliminary

< 0.7 90% CL

7.5±0.9±0.8

Γee Br(J/+–), eV

Solution1 Y(4008) Solution2

Solution1 Y(4260) Solution2 Y(4008)

Y(4008)7.4

arXiv:0808.1543

Y(4260)

e+e– → γISR +–

Y(4325) 8σ

Y(4660) 5.8

670 fb-1

PRL 99, 142002 (2007) PRL 98, 212001 (2007)

Y(4660) ?

Y(4325)

298 fb-1

Y(4360) Y(4660) 6.1σ

PRD78,014032(2008)

Combined fit

Only 1 unassigned 1– – cc level

Y(4660)

Y(4325)Y(4260)

Y(4008)

Durham Data Base

325) y

360) ψ

No evidence for Y 1-- → hadrons

X.H. Mo et al, PL B640, 182 (2006)

( → J/+-) = 0.104 ± 0.004 MeV (→ J/+-) = 0.044 ± 0.008 MeVMuch larger than measured

charmonium widths:

(Y(4260) → J/+-) > 0.508 MeV @ 90% CL

e+e– →

(e+e–→open charm)D*D*

Λc+Λc

PRD77,011103(2008)

PRL100,062001(2008)

PRL98, 092001 (2007)

PRL101,172001(2008)

DD*π arXiv:0908.0231

0908.0231[hep-ex]

DD*πY(4260) ψ(4415)

M(DD*)

Y(4260) is DD1 molecule/ccg hybrid? DD1 [→DD*π] decay should dominate but no signal found

Y(4008), Y(4260), Y(4360), Y(4660) don’t match peaks in D(*)D(*) Xsection

Y(4660) mass is close to Λc+Λc

– peak

ICHEP2008 Galina Pakhlova, ITEP

PRL 99,142002(2007)

ee→ΛΛ via ISR

PRD73,012005(2006)

ee→pp via ISR

PRL 99,142002(2007)

ee→ΛΛ via ISR

PRD73,012005(2006)

ee→pp via ISR

• no peak-like structure

• X(4630) = Y(4660) = = charmonium state 53S1 or 43D1 J.Segovia, A.M.Yasser, D.R.Entem, F.Fernandez

• Charmonium state 63S1 B.Q.Li and K.T.Chao

• Threshold effect E.Beveren, G.Rupp

•Y(4660) =ψ(2S)f0(980) bound state F.K.Gou,C.Hanhart, S.Krewald,U.G.Meissner

• Point-like baryons R.B.Baldini, S.Pacetti, A.Zallo

• X(4630) = Y(4660) D.V.Bugg

• X(4630) = Y(4660) = = tetraquark D.Ebert, R.N.Fausov, V.O. Galkin

• X(4630) ≡ Y(4660)? JPC=1– –

e+e–→Λc+Λc

– γISR

Phys.Rev.Lett.101,172001(2008) Interpretations for X(4630)

PRL 97, 242001 (2006)

6.2σ B–→Λc+p π–─

PRL 97, 242001 (2006)

6.2σ B–→Λc+p π–─

• dibaryon threshold effect?• like in B→pΛπ, J/ψ→γpp

DD DD* D*D*

Λ+c Λ–

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

States near 3940 MeV

M = 3942 +7 ± 6 MeV

tot = 37 +26 ±12 MeV

Nsig = 52 +24 ± 11 evts

PRL 100, 202001

e+e- J/ DD*

M(DD*)M≈3940 ± 11 MeV≈ 92 ± 24 MeV

PRL94, 182002

M = 3929±5±2 MeV

tot = 29±10±2 MeV

Nsig = 64 ± 18 evts

PRL 96, 082003

X(3940) Y(3940) Z(3930)

not seen in J/ not seen in DD* Probably the c2’probablydifferent

BaBar: PRL 101, 082001

M≈3914 ± 5 MeV≈ 33 ± 10 MeV

New peak in J/

M: 3914 3 2 MeV, : 23 10 +2 -8 MeV,

Nres = 55 14 +2 -14 events

Signif. = 7.7,

Background only fit

The 4 states near 3940

X(3940)Y(3940)

Z(3930)

Mass(GeV)

This X(3915)

Width(GeV)

Range: ((stat.)(sys.))

Good overlap withBaBar “Y(3940)” values

X(3940)c

Only JP=0- or 0+ charmonium is produced in pair with J/.

Radial excitations are not suppressed

e+e- → J/ + ccMissing mass technique

M = 3942 ±6 MeV

tot =37 ±12 MeV

+7−6

+26 −15

X(3940) → DD*

M= 4156 15 MeV

tot = 139 21MeV

+25−20

+111 −61

X(4160) → D*D*

M(DD*) M(D*D*)

Exclusive reconstruction of cc

Double charmonium production

cc assignments for X(3915), X(3940) & X(4160)?

3940MeV4160MeV

•Y(3915) = co’? (J/) too large?•X(3940) = c”? mass too low?•X(4160) = c’’’? mass way too low?

c’’’

3915MeVc0’

States decaying into J/

PRL102, 242002 (2009)

D*D*ssDD**ss molecule? molecule? [cs[cscscs] tetraquark?] tetraquark?

M = 4143.0 ± 2.9 ± 1.2 MeV

= 11.7+8.3-5.0 ± 3.7 MeV

Y(4140) J/ by CDFB+ Y(4140) K+

14±5 ev>3.8

2sBEE J/ψM

Preliminary Preliminary 9.15.7 9.44.4

Br(B+→Y(4140)K+) Br(Y→J/)

CDF (9.0 ± 3.4 ± 2.9)10-6

Belle <6 10-6 at 90% CL

M(X(4350))=4350.6+4.6-5.1± 0.7 MeV

Γ=13.3+17.9-9.1 ± 4.1 MeV

JP=0+: ΓγγBr(X(4350)) →J/) =6.4+3.1-2.3 ± 1.1 eV

JP=2+: ΓγγBr(X(4350)) →J/) =1.5+0.7-0.5 ± 0.3 eV

•No Y(4140)•Another structure:

Study of J/

825fb-1

8.8+4.2-3.2 ev

3.2-3.9

Z(4430)+ and Z1(4050)+ & Z2(4250)+

Smoking guns for charmed exotics:

K*(1430) → K+-

K*(892) → K+-

B → K ′

M2(K+-)

The Z(4430)± ±’ peak

±’)

BK +’

Z(4430)

M () GeV

evts near M(’)4430 MeV

±’)

M2() GeV2

“K* Veto”

Shows up in all data subsamples

But…

BaBar doesn’t see a significant Z(4430)+

“For the fit … equivalent to the Belle analysis…we obtain mass

& width values that are consistent with theirs,… but only ~1.9from zero; fixing mass and width increases this to only ~3.1.”

Belle PRL: (4.1±1.0±1.4)x10-5

Reanalysis of Belle’s BK’ data using Dalitz Plot

techniques

2-body isobar model for K’

K2*’

Our default model

K*(890) ′

K*(1410) ′

K0*(1430) ′

K2*(1430) ′

K*(1680) ′

Results with no KZ+ term

fit CL=0.1%

1 2 3 4 5

Results with a KZ+ term

fit CL=36%

1 2 3 4 5

Compare with PRL results

Signif: 6.4Published results

Mass & significance similar,width & errors are larger

With Z(4430)

WithoutZ(4430)

Belle: = (3.2+1.8+9.6 )x10-5 0.9-1.6

BaBar:

No big contradiction

K* veto applied

Systematics Z(4430)+ significance

The Z1(4050)+ & Z2(4250)+ +c1 peaks

PRD 78,072004 (2008)

Dalitz analysis of B0K-+c1

M (J) GeV

E GeV ???

BKc1 Dalitz-plot analyses

Default Model

K*(890)c1

K*(1410)c1

K0*(1430)c1

K2*(1430)c1

K*(1680)c1

K3*(1780)c1

Fit model: all low-lying K*’s (no Z+ state)

a b c d g

C.L.=310-10

Fit model: all K*’s + one Z+ state

a b c d g

C.L.=0.1%

Are there two?

a b c d

? ?? ?

Fit model: all K*’s + two Z+ states

a b c d g

C.L.=42%

Two Z-states give best fit

Projection with K* veto

Systematics of B0 → K- π+ c1 fit

Significance of Z1(4050)+ and Z2(4250)+ is high.

Fit assumes JZ1=0, JZ2=0; no signif. improvement for JZ1=1 &/or JZ2=1.

M=1.04 GeV; G=0.26 GeV

Bottomonium

Discovery of ηb

PRL 100, 06200 (2008)

non-peaking background subtracted

γISRχbJ

Y(3S)→γηb

120M Y120M Y(3S)(3S)

100M Y100M Y((22S)S)

arXiv:0903.1124

Y(2S)→γηb

non-peaking background subtracted

ηb3.5σ

MeV8.19.9392 6.48.4

MeV7.29.9388 1.33.2

M(ηb) = (9390.4 ± 3.1) MeV/c2

M(Υ(1S)) - M(ηb) = 69.9 ± 3.1 MeV/c2

Theory ~ 60 MeV/c2

•Decay modes of ηb are not known

•Search for Y(3S), Y(2S)→γηb

with e+e → Υ(3S), Υ(2S) •Monochromatic line in photon energy spectrumProblem: peaking backgrounds

• Υ(nS) → χbJγsoft, χbJ → Υ(1S) γhard • e+e→ γISRΥ(1S)

Y(5S) & Y(6S)arXiv:0810.3829

7.9fb1

arXiv:0809.4120

3.9fb1

Both inclusive and exclusive dipion cross-sections are inconsistent with PDG Y(5S) &Y(6S) parameters

Energy scan above Υ(4S) to search for counterpart of Y(4260) in bottomonium sector: study cross section ofe+e → Υ(nS)π+π, (n=1, 2, 3)

Fit to inclusive cross section e+e→hadrons coherent Y(5S) +Y(6S) + continuum

(5S) ≠ Υb at 3 level

SummaryX(3872): at D*0D0 threshold, narrow, isospin violating mode is not suppressed.

1-- family: Y(4008), Y(4260), Y(4360), Y(4660) – no room in charmonium table, big (Y→ +-), no decays to hybrid favorite D**D

3940 family: X(3940), Y(3940), X(4160) – no clear charmonium assignment.

Z± family: Z(4430)+ confirmed with Dalitz analysis; observation of Z1(4050)+, Z2(4250)+ → c1+.

Yb: is not equal to (5S) at 3 level.b: observed.

or Y(4325)

or Y(3915)

Summary

In contrast”(3770) only above-open-charm threshold state with an established +-J/ mode

•Discovered 1977 (Lead Glass wall)

•2003 1st evidence for ”+-J/ (BESII)

•2006 ”+-J/ established (CLEOc)

Bf=(1.9+-0.3)x10-3; (+-J/) 50keV

~30 yrs later

PRL96, 082004 (2006)

PRB 605, 63 (2005)

Rapidis et al PRL39, 526 (1977)

~230 evts

~25 evts

3rd generation expt

Back-up

• In (4S) decays B are produced almost at rest.

• ∆E = Ei - ECM/2 Signal peaks at 0.

• Mbc = { (ECM/2)2 - (Pi)2}1/2 Signal peaks at B mass (5.28GeV).

∆E, GeV

Mbc, GeV

Reconstruction of B decays

B0J/ KS

Improvement to M(D0)?

ii KEMME

Best single measurement from CLEOc:

MD0 = 1864.847±0.150 (stat) ±0.095 (syst) MeV

CLEOc uses invariant mass:

large MD0

dominatesthe error

small 0not a bigcontrib.

& only uses D0KS(K+K-) decays:

iiinv pEM 22 )()(

well known

±2x16keV±22keV

0.1 MD0

measured

Bf0.002319 evtsstat errordominates

M(D0) measurement @ BESIII

ibeambc pEM 22 )(

Use “beam constrained mass @ ”:

need toknow Ebeam preciselyUse backscattered laser beam at

the unused X-ing region to measureEbeam (&MD0) to better than ±100 keV

Approved, funded,& under construction

Interpretation 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) or 43D1(4661)

J.Segovia, A.M.Yasser, D.R.Entem, F.Fernandez Phys.Rev.D78:114033,(2008).

Charmonium hybrids The lightest hybrid is expected by LQCD around 4.4 GeV The dominant decays Y(4260)→D(*)D(*)π, via virtual D**

Zhu S.L.; Close F.E.; Kou E. and Pene O.

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 thresholds Lui X.

Formalism

B0 → c1K+-, c1 → J/, J/ → +-

described by 6 variables: M(c1), M(K), (c1), (c1), (J/), (J/)

Justification: efficiency is ~constant in (c1), (J/)

after integration over (c1), (J/) interference terms drop out.

Efficiency vs. (c1) Efficiency vs. (J/)

different parts

of Dalitz

range = (0, 2) range = (0, 2)

perform Dalitz analysis w/o considering angular variables, assume no interference between different c1 helicity states.

Formalism (2)

Amplitude

, K*(892), K0(1430), K2(1430), K*(1680), K*3(1780),

Z+ → +c1

Fit function

Signal component

c1 helicity

Binned likelihood fit

(see next slide for details on amplitude of Z+)

E s.b.Efficiency

B meson and R resonance decay form-factors Angular part

Amplitude of Z

c1 rest frame

c1 spin quantization axisin B → c1 K*(→K) decays

c1 spin quantization axisin B → Z(→c1) K decays

cosTransformation of basis vectors

The same relation for amplitudes

Comparison with BaBar

BaBar paper: Belle and BaBar data are statistically consistent.

peak in M(π+ψ) is present also in BaBar data with similar to Belle shape:

BaBarBelle

Comparison with BaBar

BaBar paper: Belle and BaBar data are statistically consistent.

peak in M(π+ψ) is present also in BaBar data with similar to Belle shape:

BaBarBelle

Why different significances are reported? (6.4σ Belle vs. 1.9–3.1σ BaBar)

assumption about background is crucial.

BaBar method is a simplification of amplitude analysis with a lot of (unphysical?) freedom in description of background.

Dalitz analysis is preferable.

Result of Dalitz fitscaled down by 1.18 to account for smaller statistics @ BaBar.

• Z(4430)+ signal in BK’ persists with a more complete amplitude analysis.– signif. ~6, product Bf ~3x10-5 (with large errors)

• No significant contradiction with the BaBar results – signif. = 2~3, Product Bf<3x10-5

• Z1(4050) & Z2(4250), seen in BKc1, have similar properties (i.e. M & ) & product Bf’s– signif. (at least one Z+)>10; (two Z+ states)>5

Summary on Z±

Heavy Quarkonium Roman Mizuk, ITEP RAS session at ITEP, 24 Nov 2009.

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