Recent CLEO results on hadron spectroscopy

Recent CLEO results on hadron spectroscopy

Tomasz SkwarnickiSyracuse University

Concentrate on the most recent results (mostly quarkonium spectroscopy).

Epiphany 2005, Krakow Tomasz Skwarnicki 2

Production of b-quark hadrons

SSS S,5S

s

Other states

b

b b

b

e

e

e

e

Soft g

Hard g

Long distance interactions

Short distance interactions

bb spectroscopy bq, (cq, cc) spectroscopy

W

3S ~ 24 keV

4S ~ 24 000 keV

s

c

q


• B physics runs ((4S)) at CLEO ended in mid 2001.

1

10

100

fb-1

/year

0.1

30.001

0.01

History of CLEO/CESR

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

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

BaBar

Belle

• CLEO-c phase 2003 – (2007)

CLEO-c

• Long runs at (5S) (3S), (2S),(1S) in 2001 – 2002.

(5S)

or #

of r

eson

ance

s


CLEO-III data samples

• CLEO “owns” the field of spectroscopy

• Recently more than 10-fold increase in statistics for the narrow resonances over the previous generation of experiments

• Except for a few systematics limited measurements CLEO is no longer competitive in B physics

(1S)

(3S)

(2S)

(in millions of resonance decays)

(4S)

Continuum below (4S)

(in integrated luminosity fb-1)

• Large increase in statistics for 5S with much improved detector leads to a measurement of Bs production rate

(5S)


Superconducting CESR-cwiggler magnet (2.1 T)

Wigglers needed for low energy operations to increase radiation damping(to keep the size of the beams small)

e+e- collider

No.Of

rings

Instantaneous peak luminosity cm-2 s-1

Beauty Threshold Region

CESR(-b) 1 1.2 1033

PEP-II 2 9.2 1033

KEK-B 2 13.9 1033

Charm Threshold Region

SPEAR II 1 6 1029

BEPC 1 5 1030

CESR-c1 wiggler (fall 2002)

12 1031

6 wigglers (fall 2003) 5 1031

12 wigglers (fall 2004) projected

6 1031

Up to 3 1032

BEPC-II (2007) 2 1 1033

CESR-cCESR(-b)

CESR (single ring machine) PEP-II (double ring machine)


CLEO-c data samples

• Proposed CLEO-c program:– 3 / 3 / 1 fb-1 at Ebeam=3770 / 4140 / 3100 MeV for DD / DsDs / J/– Would also like to take some(2S), c data and perform scan of R – Likely to be revised if CESR-c doesn’t reach its projected luminosity soon

• Advantages of threshold production of D(s) mesons:– Fully reconstruct one D(s) meson, then look at the other– No backgrounds (often limiting factor for D studies at B factories and fixed target

experiments)– Measurement of absolute branching fractions

~107 pb-1~6 pb-1We are continuingto run at (3770)

3640 3680 3720 3760 3800 3840


CLEO-c data samples

• (2S) sample smaller (larger) than that of BES (Crystal Ball) with much better detector

(3770)

• (3770) sample much larger than those of Mark III and BES with much better detector

(2S)

(in millions of resonance decays)


CLEO EM Calorimeter COIL (1.5T)

Detector Calorimetercrystals

E resolution at E=100 MeV

Number of inner segments (crystals)

Inner radius(cm)

CLEO-III CsI(Tl) 4.8 MeV 7800 100

CUSB-II BGO 4.2 MeV 72 8

Crystal Ball NaI(Tl) 4.8 MeV 672 25

BES-II Sampling 70 MeV

• Essential for photon spectroscopy– ~8000 CsI(Tl) crystals + photo-diodes– First crystal calorimeter in magnetic

field• In operation since 1990 (CLEO II)

Much better efficiencyin hadronic events

Narrower0 width


CLEO III Tracking• Large drift chamber in 1.5T field (lowered to 1.0T for

CLEO-c)

Stepped endplate toaccommodate newmicro- quadrupoles

Deconstruction of CLEO II DRCLEO III DR


CLEO-c Inner Wire Chamber • CLEO-III Silicon Vertex Detector deteriorated due to radiation damage

and had to be replaced• “ZD Inner Chamber” commissioned Aug/Sep 2003 • The only new detector component of CLEO-c

6 stereo layers 53 to 105 mm radius

Detector Magnetic field

p /p resolution at p=1 GeV

dE/dXresolution

CLEO-c 1.0T 0.5% 6.0%

BES-II 0.4T 2.4% 8.5%

Mark-III 0.4T 2.1%

Tracking resolution

• Much improved momentum and dE/dX resolution compared to the previous charm-threshold experiments


CLEO-III RICH• LiF – MWPC (Methane +

TEA) proximity focused RICH

RadiatorsLiF

PhotodetectorsMWPC

(Methane+TEA)

CLEO-c

B physics

Kaon efficiency = 0.80= 0.85= 0.90

First detector operating at charm threshold with excellent particle ID

In operation since 2000


Measurement of fD

Calculate Missing-Massto separate

signal (MM=m=0)from backgrounds:


Measurement of fD

D- KL -

D- -

8 events (1 background event expected)

Based on 6 wiggler data: 60 pb-1 (29k tagged events)

B(D- -) = (3.5±1.4±0.6) 10-4

fD- = (202±41±17) MeV

First statistically compelling evidence for this decay. (BES 2.7±1.7 events hep-ph/0400150)Need much larger statistics to constrain the theory (data taking in progress!)The same type of calculations used for fB needed for extraction of Vtd from B0B0 mixing

hep-ex/0411050 Accepted by PRD


D meson BRs

0.0380±0.0009

0.130±0.008

0.075±0.003

0.092±0.006

0.0141±0.0008

Using double-tag method (Preliminary)

PDG 2004

Future goal: reduce errors to 1-2% for the major modes

No surprises


Heavy Quarkonia bb

S= 0 1 0 1 0 1 L= 0 1 2

?

cc

n 2S+1 L J

S= 0 1 0 1 0 1 0 1 L= 0 1 2 3

n=1

n=2

n=3

n=4

Hyperfine splitting: 1 2S S

Fine splitting:

1 2 1 2

,L S

S r S r S S

n=1

n=2

Hyperfine splitting

Fine splitting

J 1974

’’ 1974

c 1975

c 1980

c’’ 1982 hc

19861992

2002

1977

’’ 1977

’’’ 1979

b 1983

b’ 1982

2 2002’’’ 1977

’IV 1981

2004

CLEO-III

E835CLEO-c

Belle,BaBar,CLEO


Fine and Hyperfine Structure

• nS states are special:– Have no fine structure (L=0 thus J=S)– The only states for which hyperfine structure is predicted to be significant– Observed in charmonium:

• M(J/) – M(c)= (116±2) MeV; M(’) – M(c’)= (48±4) MeV

• If long range spin-spin forces are negligible then for L>0:– MS=0 = M(c.o.g.) = J (2J+1) MJ

S=1 / J (2J+1)– M(hc)=(5 M(c2)+3 M(c1) + M(c0)) / 9 = (3525.3±0.1) MeV ???

n, L

c.o.g

L S

Spin-orbit

1 2 1 2r rS S S S

Tensor

J = L - 1

J = L + 1

J = L1 2S S

Spin-spin

J = L

S = 0 S = 1Fine structureHyperfine structure


Inclusive search for hc

0

’

hc

c

• Require 0 recoil mass to be consistent with the c mass

• Plot 0 recoil mass (should reflect the hc mass)

hc

156 ± 48 events3.3significant

anything


Exclusive search for hc

0

’

hc

c KsK,2K0,2K24,2

• Reconstruct c in one of the exclusive decay modes

• Then follow the same steps as in the inclusive analysis

hc15.0 ± 4.2 events5significant

c mass sidebandsData MC

Signal sample ’ 0 hc 0 c

Optimize c reconstruction on ’ cc


Preliminary CLEO results for hc mass

For comparison: hep-ex/040085Preliminary E835 results:

Disapprove E760 evidence for pp hc J ~13 pp c events in the peak~3.3 significance for hc

M(hc) = 3525.8±0.2±0.2 MeV

E835

• Inclusive analysis: M(hc)= (3524.8±0.7) MeV• Exclusive analysis: M(hc)= (3524.4±0.9) MeV• Together:

M(hc)= ( 3524.7 ± 0.6 ± 1.0 ) MeV M(c

cog) - M(hc) = ( 0.6 ±1.2 ) MeV• Consistent with zero• In any case small as expected

• The analysis is still in progress and numbers will change slightly before they are published


Search for X(3872) in fusion and ISR• Reconstruct exclusive J/, J/ events in CLEO-

III high energy data (15 fb-1)Untagged fusionJPC=0±+,2±+,…

Initial State RadiationJPC=1

_ _

No signal found

hep-ex/0410038Accepted by PRL


Search for X(3872) in fusion and ISRAssuming B(B± → K± X) ≈ B(B± → K± ψ’) → B(X → π+ π- J/ψ) ≈ 0.02our limits imply:

(2J+1)X(3872)) < 0.65 keV

• ¼ that for χc0 and χc2

• Ackleh &Barnes prediction for 11D2 state: (2J+1)(11D2) keVee(X(3872)) < 0.42 keV• comparable to ψ(3770)• ½ that of ψ(4040)


Determination of B((nS) )Measure yields on and off the resonance peaks

• Much larger samples than previously available

• Much better detector than previously available (tracking, calorimeter, muon system)


• Compared to the previous measurements:– Good agreement for (1S)– Substantial disagreement for (2S), (3S)

Determination of B((nS) )CLEO-III

hep-ex/0409027Accepted by PRL


Determination of tot((nS))

B((nS) ) are important for determination of tot((nS))

and CLEO-III values for B and PDG values for B

• Important change for many comparisons of data (Bx) vs theory (x): Bx=x/tot


Photon transitions – E1

123

456

7891011

1213,14,15

16,1718

J=210

J=210

BR * tot E1

E M(n3PJ)

• Electric Dipole Transitions

g g gHadrons (…0..)

g g g

123

5,46

(2S)

21 3

65,4

(2S)87 9

65,4

1211,10

1514,13

16,1718

(3S)

22 3

E1 f f iQ iL r Le n n E

g g

cc

bb


Photon transitions – E1

123

789

J=210

J=210

(2S)

(2S)

cc

bb(3S)

1

1 2

2

3

3 879

hep-ex/0408133 Accepted by PRD

hep-ex/0408133 Accepted by PRL

16,1718

(3S)

18

16,1733S1 13P0


Comparison to previous measurements - examples(2S) bJ(1P2) (3S) bJ(2P2)

Good agreementon Ei.e.mbJ

Disagreements on B((3S) bJ(2PJ))

Improvedprecision


Fine splitting of P-states• Tests of relativistic corrections to the mass spectrum

01

12

mmmm

r

r(1P) 0.570.010.01

r(2P) 0.580.010.01

r(1P) 0.4900.0020.003

bb

cc

Nearly equal, against most of theoretical predictions.}

The results favor confining potential of effective scalar type

(=0.8 for pure Coulomb potential)


Relativistic effects in transition rates• In non-relativistic approximation E1 matrix

elements are spin (J) independent2

E1 E13 3(2 1) (2 1)

( )f f i i JL L

Jr

B in n fE E

(J=2)/(J=1)b(2P): (J=0)/(J=1)

(J=0)/(J=2)

1.000.010.050.760.020.070.760.020.09

(J=2)/(J=1)b(1P): (J=0)/(J=1)

(J=0)/(J=2)

1.010.020.080.820.020.060.810.020.11

(J=2)/(J=1)c(1P): (J=0)/(J=1)

(J=0)/(J=2)

1.500.020.050.860.010.060.590.010.05

Ratio of 3(2 1)( ( 1) )J

JB nS n P

E

Consistent with the NRexpectations

Relativistic effects in J=0are expected to be the largest

Smaller c-quark massand substantial 2S-1D1

mixing}cc

bb


E1 matrix elements• Large relativistic

corrections (triangles) needed to describe E1 rates in charmonium.

• Corrections small in bottomonium.

• Small matrix element 33S1 13PJ difficult to predict (cancellations)

Date ofpublication 33S1 13PJ

33S1 23PJ

S.Godfrey

23S1 13PJ

-+

McC

lary

83

Gro

tch

84 23S1 13PJ

23S1 13PJ

33S1 23PJ

33S1 13P0

<1P 0|r

|3S>

“Spin averaged” matrix elements

bb

bb

cc


Photon transitions – M1

4

A way to reach singlet states

Crystal Ball claimed observation of all M1 transitions in charmonium ~20 years ago (Direct: “1”, “2”, Hindered: “4”)

1

2

365

• Magnetic Dipole Transitions

3

g g

2

4

(2S)

(2S)

4

2

(3S)

5

6

3

3

2 2

M3

1 2

DIRECT

1

tiny

HINDERED

l

0

arge

f i

f i

f i

i f

i f

Q

Q

n n

n

L L

n L n L

n L n

E

E

n

L

mE

en n

cc

bb


Search for b(11S0)

• No signal found for this or any other M1 transition in the Upsilon system

Hindered M1

E1

E1

E123PJ13S1 M1

33S111S0

M123S111S0(2S)

(3S)

cc

bb

4

6

(4)

(6)


M1 matrix elements

• Even recent calculations only marginally consistent with our upper limit on 33S1 11S0

13S1 11S0

23S1 11S0

23S1 11S0

33S1 21S0

33S1 11S0

allowed range

Lahd

e 03

Ebe

rt 0

3

Date ofpublication


Inclusive (2S) X J/(1S), J/(1S) +-

cut cutcut cut

MCLog

scal

e !

• Large statistics, good agreement with MC precision measurement of B((2S) X J/(1S))


Exclusive (2S) X J/(1S), J/(1S) +-


(2S) X J/(1S), J/(1S) +-

• Preliminary results presented at QWG workshop Oct 2004

• Improved results are being prepared for publication.


Exclusive hadronic (2s) decays

Log scale!

• A lot of theoretical complications e.g.:

– Interference with continuum– s and relativistic

corrections• Happy with agreements

within a factor of ~2



• (2s) Dalitz plot distinctively different than continuum or J/(1S)

BESJ/

CLEO(2S)



Linear scale


Continuum production of PV at 3.67 GeVhep-ex/0407028

Epiphany 2005, Krakow Tomasz Skwarnicki 42Summary• First statistically compelling measurement of fD-

• Observe highly significant (2S)0hc,hc c signal with the hc mass consistent with the c.o.g. of the cJ states

• Non-observation of X(3872) and ee X(3872). • Precision measurements of B((nS) ). The results for

(2S),(3S) significantly different from the PDG values, impacting estimates of the total widths of these states.

• Precision measurements of photon transitions from (2S),(2S),(3S). More sensitive tests of relativistic corrections in the potential model calculations.

• Precision measurements of inclusive and exclusive transition rates for (2S) X J/(1S). Some significantly different from the previous measurements.

• Many new insights into B((2S)X)/B(J/(1S) X) for 2- and multi-body exclusive final states.

• First measurements of continuum productions of 2-body pseudo scalar-vector final states at 3.67 GeV. Ratios of cross-sections in rough agreement with SU(3) except for K*0K0

Recent CLEO results on hadron spectroscopy

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