I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 1

The Y(5S) at CLEOIntroduction

Bs Reconstruction at the Y(5S)

CLEO PRL 96, 022002 (2006)

B Reconstruction at the Y(5S)

CLEO PRL 96 152001 (2006)

Inclusive Ds production at the Y(5S)

CLEO PRL 95 261801 (2005) + update CLEO Conf 06-16

Inclusive phi production at the Y(5S)

CLEO Conf 06-16Ian ShipseyPurdue UniversityFor the CLEO Collaboration

I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 2

• The Y(5S) discovered by • CLEO & CUSB in 1985.

massive enough to decay into :

• Knowledge of Bs production at Y(5S) essential for assessing the potential of Bs physics at a high luminosity e+e collider.

• A clean source of BS decays is valuable to interpret New Physics found directly at the LHC.

* * *

* * *

* * *

, , ,

, , , ,

, ,s s s s s s

BB BB B B

BB BB B B BB

B B B B B B

Introduction

( (5 ) (10.865 0.008) GeV

(110 13) MeV

M Y S

(5 )S

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Y(5S) Brief History

• CLEO & CUSB scan in 1985 0.07 fb-1 & 0.12 fb-1

taken on peak

CLEO PRL54 381, 1985

CUSB PRL54, 377, 1985

•CUSB fit to modified potential model

Y(5S) Y(6S)?

But no conclusive evidence for Bs production at Y(5S)

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Return to Y(5S) • New Data

– CLEO III 2003 0.42 fb-1 at 10881 MeV– BELLE 2005 1.86 fb-1 at 10869 MeV (Talk of Drutskoy)– BELLE June 2006 19 fb-1 at 10869 MeV (to be analysed)

• Analysis differences between Y(5S) and Y(4S):

– The ratio of resonance to continuum is larger at the Y(4S) – Same continuum data used for both Y(5S) and Y(4S). But continuum data

is almost 300 MeV in CME below Y(5S) and is usually taken at different times. So the continuum subtraction becomes a significant systematic error

– Cross sections measured in 1985 have been re-measured– CLEO: (0.301±0.002±0.039) nb – BELLE: (0.305±0.002±0.016) nb – Excellent agreement

( (5 )) ~ 0.3nb ( (4 )) ~ 1nbe e S e e S ( ) ~ 3e e qq nb

I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 5

• An extension of B meson reconstruction technique used at the Y(4S) – –

beamBss EEBBSYs :)5(

*

* *(5 ) :s

s s beamBY S B B E E

beamBbeamBss EEEEBBSYss ,:)5( *

*

2 2bc beam candidateM E P

beamcandidate EEE

ss BB

*ss BB

**ss BB

MC

* * *s

bc

*

, , reconstruct at

different locations in M plane

without need to reconstruct the

in

s s s s s

s s

B B B B B B

E

B B

CLEO Result 1: Observation of the Bs @Y(5S) Exclusive reconstruction of the Bs

CLEO PRL 96, 022002 (2006.)

Case 1

Case 2

Case 3

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4 events Y(5S) Bs* Bs*:

3 BsJ/ ,

1 BsJ/.

CLEO Result 1: Observation of the Bs @Y(5S)

s sB B

*s sB B

* *s sB B

/ modesJ

* *s sB B is dominant

/ , /S sB J B J

I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 7

10 events Y(5S) Bs* Bs*:

Bs Ds(*) /(4 Ds modes)

* * 0.040.03

*s

( ) (0.11 0.02)nb (>5 )

m(B ) (5413.6 1.0 3.0)MeV

s se e B B

~ 2/3 of cross section expected to be ordinary B me sons

s sB B * *s sB B

*s sB B

(*)sD

modes

* *s sB B is dominant

* *s s

Belle: most

events also

B B

SD modes (*)S SB D /

+14-12(37 4)% of resonant cross section

(*) (*)

0.140.12

( (5 ) )

0.37 0.04

s s s

s

f B Y S B B

f

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CLEO Result 2:Ordinary B mesons @ Y(5S)

• The Y(5S) resonance can decay into a variety of states with ordinary B mesons:

• 7 possibilities:

The center of the signal band for ordinary B mesons

The center of the signal band for Bs mesons

)(BB

*BB **BBBB

ssBB *ssBB **

ss BB

)(BM )( sBM

* * *

* * *

, , ,

, , ,

BB BB B B

BB BB B B BB

MC

Ordinary B decay modes occupy a differentregion on the ΔE-Mbc plane& have distinct decay modes

Use same analysis techniqiuedeveloped for Bs mesons in previous analysis.

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With more BB final states (7) Mbc plane is slightly more complicated.

* * *4 states: , , ,

easily distinguished: monochromatic or

narrow p interval

BB BB B B BB

Ordinary B Mesons @ Y(5S)

DataMC

BD(*)( or ) & B J/ K(*)

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Ordinary B Mesons @ Y(5S)

Use BD(*)( or ), B J/ K(*)• Production largest for B*B*,

consistent with models– BB/B*B* < 22% @ 90% cl– BB*/B*B* = (24±9±3)%

• BS* mass– M(BS*)-M(B*)=(87.6±1.6±0.2) MeV– M(Bs*)=(5411.7 ± 1.6 ± 0.6) MeV– M(BS*)-M(BS)=(45.7±1.7±0.7) MeV

consistent, as expected from Heavy Quark Symmetry with

– M(B*)-M(B) =45.78±0.35 MeV

1-D projection beam constrained mass with suitable cuts on E

B*B*

BB*BB BB(*)

BB

CLEO

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Ordinary B mesons @ Y(5S)

Determine yield from

BD(*)( or ) & B J/ K(*)with B invariant massTotal of 53±9 events

=0.177±0.030±0.016 nb,

59% of resonance cross section combine with

the sum = (0.286 ±0.040) nb saturates (within the stats.)

Compare to total cross section

• Translates to fS=0.41±0.10±0.10

Invariant mass

(*) (*)

0.140.12

( (5 ) )

Ordinary B (1 )

0.41 0.10 0.09

0.37 0.04

s s s

s

s

s s

f B Y S B B

f

f

B f

* * 0.040.03( ) (0.11 0.02)nb s se e B B

( (5 )) (0.301 0.002 0.039)nb e e S

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Model Dependent BS Fractions, fS

• Method use inclusive yield• Choose a particle that has very different

decay rates from B & BS

– Ex: DS

5( (5 ) ) 2 ( ) (1 ) ( (4 ) )

S s s S Ss sB Y S D X N B B D X B Y Xf Df S

(*) (*)( (5 ) )s s sf B Y S B B

measure measureModel estimate based on quark level diagrams and measured ordinary B decay rates

B(BS→DS X) =(92±11)%

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Y(5S)Y(4S)

Y(4S)

Y(5S)

continuum

(21.2 1.8 5.5)% hep-ex/0605110sf

8.84.2(21.8 3.4 )%sf

Measurement of fS

from Ds Yields -data

(Belle)

(CLEO)

Result4

,

& ( ) (3.5±0.4)%

(from hep-ph/0605134)

S

S

Use D

B D

x ( |p|/Ebeam )

Bra

nchi

ng F

ract

ion

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Measurement of fS Using Yields

• Here we need B(BS → X)• Use CLEO-c inclusive yields for

B(Do → X)=(1.0±0.10±0.10)% B(D+ → X)=(1.0±0.10±0.20)%

B(DS → X)=(15.1±2.1±1.5)% Preliminary [hep-ph/0605134 ]

• From B(B → X)=(3.5±0.3)%, ascertain that most of ’s arise from B →D & DS→

• Predict that B(BS → X)=(14.9±2.9)%

Result4

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Measurement of fS Using Yields -data• CLEO inclusive yields, for x<0.5, R2<0.25

+14.6s - 6.1f =(27.5±3.2 )%

Y(5S)Y(4S)

x ( |p|/Ebeam )

Bra

nchi

ng F

ract

ion

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Measurement of B(Y(5S) BS(*)BS (*)) Using DS & Mesons

74

CLEOaverage

of , , inclusive

& ordinary B

exclusive

(26 )%

s

s

D

f

[1] CLEO [PRL 95, 261801 (2005)]

[2] CLEO [PRL 96 152001(2006)] (e+e- Y(5S)) = (0.301± 0.002 ± 0.039)nb

SUMMARY

+14-12

S

In good agreement

with

=(37 4)%

CLEO exclusive

B reconstruction

sf

310310

I. Shipsey Heavy Quark Physics ICHEP06 7/27/06 17

5.04.6

, incl.,

ordinary B excl.

(22.6 )%

s

s

D

f

Summary of fS Measurements

• Plot: statistical & systematic uncertainties added linearly

• Average takes into account correlated syst. uncertainties on Y(5S) cross-section

• model dependencies on Inclusive yields

+11-9

S

=(31 6)%

B reconstructiom

not in average

sf

Plot adapted form Stone SuperB Workshop SLAC 6/2006

+0110-09

S

0.31 006

CLEO B reconstructiom

Combine with Belle

+14-12

S

In good agreemnt with

=(37 4)%

CLEO exclusive

B reconstruction

sf

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Summary 1st Observation of the Bs at the Y(5S) and determination of the

composition of BsBs final states. Bs*Bs* dominates • 1st determination of the composition of ordinary BB final

states at Y(5S). B*B*:BB*:BB ~ 3:1:<1, – Upper limits for BB ,B(*)B(*)and BBBs*Bs BsBs.

• Both Bs & B compositions consistent with predictions• M(Bs*)=(5411.7 ± 1.6 ± 0.6) MeV world’ best measurement.• M1 Mass splitting: M(BS*) - M(BS) = (45.7 ± 1.7 ± 0.7) MeV as expected by HQS:Inclusive yields of Ds and phi mesons measured for the first time Bottom line: between about ¼ (0.07 nb) & 1/3 (0.11 nb) of Y(5S) decays to BS

(*) BS(*)

These estimates are model dependent and indicate that anextended Y(5S) run at a B factory would be fruitful.

Belle results from 1.8/fb run are in broad accord with the above results

* * 0.040.03

* *

( ) (0.177 0.030 0.016)nb ( ) (0.11 0.02)nb

( ) (0.287 0.04)nb ( (5 )) (0.301±0.002±0.039)nb

s s

s s

e e BBX e e B B

e e BBX B B e e S

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Additional Slides

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Y5S

Y4S

(21.2 1.8 5.5)% hep-ex/0605110sf

Result3

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Comparisons with Models

• UQM predicts R~0.4, fS=38%, BS*BS* large

• QHM predicts R~0.7, fS=21%, BS*BS* large

• Other models:– Martin & Ng, Z

Phys. C 40, 133 (1988)

– Byers [hep-ph/9412292

Unitarized Quark Model

..... ..

.. ...... . .. .. .

Y(5S)

Quark Hybrid Model

Y(5S)

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Model of DS Production

• Must assume knowledge of B(BS→DS X)

• Account for fragmentation that reduces DS rate from BS, CLEO & BELLE use same model B(BS→DS X) =(92±11)%