CESR and CLEO - Cornell University50 µm pitch 150 MΩ, 150 pF Silicon Sensor 27.0 x 53.2 mm2 511...

Klaus Honscheid, LP 99 1

CESR and CLEO

Lepton Photon 99Klaus HonscheidOhio State University


9.44 9.46

Mass (GeV/c2 )

0

5

10

15

20

25

s (

e+e

- ®

Ha

dro

ns)

(nb

)

¡(1S)

10.00 10.020

5

10

15

20

25

¡(2S)

10.34 10.370

5

10

15

20

25

¡(3S)

10.54 10.58 10.620

5

10

15

20

25

¡(4S)

Where to “B” To measure a key CP parameter (sin(2β)β)β)β)) to ~ 10 % requires:

a few hundred B0→→→→ J/ψψψψKs events+ fully reconstructed, flavor tagged+ BR’s, efficiency, tagging…

30x106 BB events (Y(4S))

e+e- Annihilation

Hadro-Production

σσσσ ~ 100 µµµµb (Tevatron)S/N ~ 1/500

σσσσ ~ 1 nbS/N ~ 1/3


C E S R P e a k L u m i n o s i t y

1993 1994 1995 1996 1997 1998 19990

2

4

6

8

10

Lum

inos

ity

(10

32 c

m-2 s

ec-1

)

CLEO II.V Integrated Luminosity (9 fb-1

)

Nov

Dec Jan

Feb

Mar

Apr

May

Jun

Jul

Aug Sep

Oct

Nov

Dec Jan

Feb

Mar

Apr

May

Jun

Jul

Aug Sep

Oct

Nov

Dec Jan

Feb

Mar

Apr

May

Jun

Jul

Aug Sep

Oct

Nov

Dec Jan

Feb

Start Nov 16, 1995 1996 1997 1998 1999

Inte

grat

ed L

um

inos

ity

(fb-1

)

on 4S Cont. [fb-1]

CLEO II 3.1 1.6CLEO II.5 6.2 2.8

Total 9.3 4.4

CLEO Datasample

CESR Performance

Peak Luminosity: 8.5 x 1032 cm-2 s-1

Integrated 40 pb-1 (Day)Luminosity 750 pb-1 (Month)

4400 pb-1 (Year)


I

II

d t = 3 0 f b 1/ y e a r

y e a r ( % ) = IIy e a r / p k

pk[

(1

/cm

2)

(1

/s)

]

1 03 5

1 03 4

1 03 3

1 03 2

1 03 1

1 03 0

1 02 9

5 6 7 8 9 1 0 2 0 3 0 4 0 5 0

1 1 6 0 8 9 9 - 0 0 2

C E S R ' 9 8' 9 7

' 9 6' 9 2' 9 1

L E P ' 9 2L E P ' 9 7

D O R I S ' 8 9P E P ' 8 4

B E P C ' 9 2

S L C ' 9 2

CESR Performance

Snow

mas

s Yea

r


Superconducting RF• More Power

1 A beam current

• Less Impedance 4 RF cells vs. 20 Reduced Instabilities

• Higher GradientShorter Bunches

• Installed

I n s t a b i l i t y T h r e s h o l d s C u r r e n t s f o r a P o s i t r o n B e a m

To

ta

l

Cu

rr

en

t

(m

A)

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

1 4 , 1 4 , 1 4 1 4 , 1 4 , 2 8 1 4 , 2 8 , 1 4 2 8 , 1 4 , 1 4

A p r 9 7 - 4 N R F ; 0 S R FN o v 9 8 - 2 N R F ; 2 S R FM a y 9 9 - 0 N R F ; 3 S R F

T i m e b e t w e e n B u n c h e s w i t h i n t h e T r a i n [ n s ]

Expect to reach 2 x 1033 cm-2 s-1 sometime next Year.

CESR Upgrades

Superconducting Quads• Better focus

ββββ* from 18 to 13 mm

• Spring 2000


-2.70

-1.44

1.12

-1.04

0.42

0.22

-0.21

1.52

Charged Particle Tracking

Charged Multiplicity ~ 10Typical Momentum ~ 700 MeV/c down to 100 MeV/c

Momentum Resolution = f(Length, Multiple Scattering)

CLEO II CLEO III: 20 cm smaller radius (RICH)Final focus quads

Klaus H

onscheid, LP 99

8

CLEO III Driftchamber

Conical Endplate0.6”Al, 3” pitch8100 cells31 stereo layers

Tapered Inner Section8 rings, 1696 axial cells16 layers


He:Propane Xo > 330 m60:40 Lorentz Angle (@ 1.5 T) < 46o

Ar:Ethane Xo = 165 m50:50 Lorentz Angle (@ 1.5 T) < 69o

Improved efficiencyImproved resolution122 µµµµm -> 112 µµµµm Improved dE/dx

Reduced Multiple Scattering

2.5 mm Rohacell with 20 µµµµm Al skinsXo < 0.15%No support function

Inner Gas Seal

He based Gas MixturesResolution Efficiency

Test Beam Results (CLEO II.5)

All B-Factories useHe-based drift chamber gases


MovingDay

EndplateView


CleoXD

Run: 82205Event: 12186

1 mm

p-

p+

K+

p-

p

-K

+

p+

p-

D0

D0-Z e r o L i f e t i m e

e x p ( - t )

t e x p ( - t )

- 5 0 5 1 0

t2e x p ( - t )

D0 L i f e t i m e s

D e c a y

I n t e r f e r e n c e

M i x i n g

Charged Particle Tracking

D*+ ® D0p

+, D0 ® K-p

+

Eve

nts

/0.1

D0 L

ifet

imes

0

500

CLEO II.V

tD0=403.5–4.1fs

~ 0.5% bkgd

st ~ 0.5tD0

D0 Lifetimes


Silicon Vertex Detector

4 Layers of double sided silicon detectors, 300 µµµµm thick.Only active elements and minimal support material in detector fiducial regionNo support structure outside outermost silicon layer.Conical support structure to maximize acceptance.


Read Out Electronics

Flex Cable511 channels50 µµµµm pitch

Front End128 channels50 µµµµm pitch150e + 5.5 e/pF

Back End (SVX-CLEO)128 channels50 µµµµm pitch8-bit ADC, sparsifierserial output

R/C Chips128 channels50 µµµµm pitch150 MΩΩΩΩ, 150 pF

Silicon Sensor27.0 x 53.2 mm2

511 strips per side50 µµµµm r-f 100 µµµµm z

• Up to 5 silicon sensors daisy-chained to one readout.• Radiation hard (100 kRad)• Very low noise, Viking based Front-End chip.• Back-End chip based on SVX II• BeO Hybrids mounted on copper cones (cooling)• S/N > 15:1 (worst case)


Layer 3

Vertex Detector Assembly

Layer 4


How to measure Vcb? HQET: use B→→→→D*l νννν at q2

max

D* at rest (in B frame)

with D*→→→→Dππππ and almost no phasespace the ππππ is as rest as well.

How to find a ππππ at rest?

With good resolution(at low energies)and high granularitytry:

π0’s

w1 . 0 0 1 . 1 0 1 . 2 0 1 . 3 0 1 . 4 0 1 . 5 0

3 3 3 0 9 9 4 - 0 1 64 0

2 0

0

2 0

0

( a ) L i n e a r F i t

( b ) Q u a d r a t i c F i t

x F

(

w

)

x

1

0|

|V

cb

3

Detecting Neutral Particles

CLEO

CLEO


Re-Stacking theCalorimeterEndcap

• CLEO pioneered use of CsI calorimeter• 7800 crystals.• 2% energy resolution at 1 GeV.• 4 mr angular resolution at 1 GeV.• no radiation damage observed.• reduced material in front of endcaps.

Electromagnetic Calorimeter

All B-Factories use CsI calorimeter


CLEO gets RICH• 4σσσσ K/ππππ separation at 3 GeV

• LiF radiator, saw tooth + plane

• N2 expansion volume (16 cm)

• TEA/CH4 based photo detector

• ~250,000 electronic channels

Search for B →→→→ ππππππππand B →→→→ Kππππ• important for CP

• very rare B0→→→→K+ππππ-

=

==

== 1.8 x 10-5

B →→→→ ππππππππ===

== ?

CLEOB0→→→→K+ππππ-

Particle Identification


Particle Identification

420 LiF radiators 300 Plane 120 Saw-tooth 17.5 x 17 x 1 cm3

UV transparent 135-165 nm


Photon Detection

MWPC + Pad Readout~230,000 pads(8 mm x 7.5 mm)TEA/CH4Gas gain ~25,000

8 CaF windows100 µµµµm strips, every 2.5 mm(field shaping)G10 frame (and ribs for flatness)

CaF, LiF Transmission ~ 90%


Arrival atWilson Lab

RICH Assembly

Klaus H

onscheid, LP 99

21

A B r i e f H i s t o r y o f C L E OC L E O I n t e g r a t e d L u m i n o s i t i e s

C L E O I I I

C L E O I I . 5

C L E O I I

C L E O I . 5

C L E O I

C L E O R e l a t e d

C E S R R e l a t e d

1 9 8 0 1 9 8 5 1 9 9 0 1 9 9 5 2 0 0 0 2 0 0 5 2 0 1 0

1 09

1 08

1 07

1 06

1 05

1 04

BB

/ Y

ea

r

b c

M i x i n gb u

b sK , K ,

/

N e wT r a c k i n g

C s I

2 c m B PS i l i c o n

3 . 5 c m B P

H e - p r o p a n e

P a r t i c l e I DN e w

T r a c k i n g

M i c r o b e t a7 B u n c h e s

1 I R

C r o s s i n g A n g l e9 X 3 B u n c h e s

S C I R Q u a d sS C R FI

CESR and CLEO - Cornell University50 µm pitch 150 MΩ, 150 pF Silicon Sensor 27.0 x 53.2 mm2 511...

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Transcript of CESR and CLEO - Cornell University50 µm pitch 150 MΩ, 150 pF Silicon Sensor 27.0 x 53.2 mm2 511...