CESR and CLEO. Lepton Photon 99 Klaus Honscheid Ohio State University. Klaus Honscheid, LP 99 1

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1 CESR and CLEO Lepton Photon 99 Klaus Honscheid Ohio State University Klaus Honscheid, LP 99 1

2 Where to B To measure a key CP parameter (sin(2β) β)) to ~ 10 % requires: a few hundred B 0 J/ψK s events + fully reconstructed, flavor tagged + BR s, efficiency, tagging 30x10 6 BB events (Y(4S)) e + e - Annihilation 25 s (e + e - Hadrons)(nb) (1S) (2S) (3S) σ ~ 1 nb S/N ~ 1/3 (4S) Mass (GeV/c 2 ) Hadro-Production σ ~ 100 µb (Tevatron) S/N ~ 1/500 Klaus Honscheid, LP 99 2

3 CESR Performance 10 C E S R P e a k L u m in o s Luminosity (10 32 cm -2 sec -1 ) Peak Luminosity: 8.5 x cm -2 s -1 Integrated 40 pb -1 (Day) Luminosity 750 pb -1 (Month) 4400 pb -1 (Year) CLEO Datasample CLEO II.V Integrated Luminosity (9 fb -1 ) on 4S Cont. [fb -1 ] CLEO II CLEO II Total Integrated Luminosity (fb -1 ) Start Nov 16, 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 Klaus Honscheid, LP 99 3

4 CESR Performance d t = 3 0 f b I 1 / y e a r [(1 /c 2 m p k )(1 /s )] P E P '8 4 L E P '9 2 B E P C '9 2 C E S R '9 8 '9 7 '9 6 '9 1'9 2 D O R I S '8 9 L E P '9 7 Snowmass Year S L C ' y e a r (% ) = II II y e a / r p k Klaus Honscheid, LP 99 4

5 CESR Upgrades Superconducting RF More Power 1 A beam current Less Impedance 4 RF cells vs. 20 Reduced Instabilities Higher Gradient Installed Shorter Bunches T o t a l C u r r e n t ( m A ) In s ta b ility T h re s h o ld s C u rre n ts fo r a P o s it , 1 4, , 1 4, , 2 8, , 1 4, 1 4 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 A p r N R F ; N 0 o v S 9R 8 F - 2 N R F M; 2 a y S 9R9 F - 0 N R F ; 3 S R F Superconducting Quads Better focus Spring 2000 β* from 18 to 13 mm Expect to reach 2 x cm -2 s -1 sometime next Year. Klaus Honscheid, LP 99 5

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7 Charged Particle Tracking Charged Multiplicity ~ 10 Typical 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 Honscheid, LP 99 7

8 CLEO III Driftchamber Tapered Inner Section 8 rings, 1696 axial cells 16 layers Klaus Honscheid, LP 99 8 Conical Endplate 0.6 Al, 3 pitch 8100 cells 31 stereo layers

9 Reduced Multiple Scattering Inner Gas Seal 2.5 mm Rohacell with 20 µm Al skins X o < 0.15% No support function Resolution Efficiency He based Gas Mixtures He:Propane X o > 330 m 60:40 Lorentz Angle (@ 1.5 T) < 46 o Ar:Ethane X o = 165 m 50:50 Lorentz Angle (@ 1.5 T) < 69 o Test Beam Results (CLEO II.5) Improved efficiency Improved resolution 122 µm -> 112 µm Improved de/dx All B-Factories use He-based drift chamber gases Klaus Honscheid, LP 99 9

10 Moving Day Endplate View Klaus Honscheid, LP 99 10

11 Charged Particle Tracking CleoXD Run: Event: K p + 1 mm p - D 0 p + p - p + - D 0 Z ero L ifetim p - K + ex p (-t) D e c a y D* + D 0 p +, D 0 K - p + tex p (-t) I n t e r f e r e n c e Events/0.1 D 0 Lifetimes s t ~ 0.5t D 0 CLEO II.V t D 0= fs ~ 0.5% bkgd D 0 Lifetimes t 2 ex p (-t) M i x i n g D 0 L ifetim es Klaus Honscheid, LP 99 11

12 Silicon Vertex Detector 4 Layers of double sided silicon detectors, 300 µm thick. Only active elements and minimal support material in detector fiducial region No support structure outside outermost silicon layer. Conical support structure to maximize acceptance. Klaus Honscheid, LP 99 12

13 Read Out Electronics Flex Cable 511 channels 50 µm pitch Front End 128 channels 50 µm pitch 150e e/pf Silicon Sensor 27.0 x 53.2 mm strips per side 50 µm r-f 100 µm z R/C Chips 128 channels 50 µm pitch 150 MΩ, 150 pf Back End (SVX-CLEO) 128 channels 50 µm pitch 8-bit ADC, sparsifier serial output 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) Klaus Honscheid, LP 99 13

14 Vertex Detector Assembly Layer 4 Layer 3 Klaus Honscheid, LP 99 14

15 Detecting Neutral Particles How to measure V cb? HQET: use B D*l ν at q 2 max D* at rest (in B frame) with D* Dπ and almost no phasespace the π is as rest as well. How to find a π at rest? x F ( w 3 V ) x 1 0 c b ( a ) L i n e a r F i t ( b ) Q u a d ra tic F it CLEO w With good resolution (at low energies) and high granularity try: π 0 s CLEO Klaus Honscheid, LP 99 15

16 Electromagnetic Calorimeter 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. All B-Factories use CsI calorimeter Re-Stacking the Calorimeter Endcap Klaus Honscheid, LP 99 16

17 Particle Identification Search for B ππ and B Kπ important for CP very rare B 0 K + π - == 1.8 x 10-5 B ππ==? CLEO B 0 K + π - CLEO gets RICH 4σ K/π separation at 3 GeV LiF radiator, saw tooth + plane N 2 expansion volume (16 cm) TEA/CH 4 based photo detector ~250,000 electronic channels Klaus Honscheid, LP 99 17

18 Particle Identification 420 LiF radiators 300 Plane 120 Saw-tooth 17.5 x 17 x 1 cm 3 UV transparent nm Klaus Honscheid, LP 99 18

19 Photon Detection MWPC + Pad Readout ~230,000 pads (8 mm x 7.5 mm) TEA/CH 4 Gas gain ~25,000 8 CaF windows 100 µm strips, every 2.5 mm (field shaping) G10 frame (and ribs for flatness) CaF, LiF Transmission ~ 90% Klaus Honscheid, LP 99 19

20 RICH Assembly Arrival at Wilson Lab Klaus Honscheid, LP 99 20

21 Klaus Honscheid, LP B B / Y e a r I A B r i e f H i s t o r y o f C C L E O I n t e g r a t e d L u m in o s it ie s C L E O R e la te d C E S R R e la te d b c M i x i n g b u N e w T r a c k i n g C L E O I.5 C L E O I M i c r o b e t a 7 B u n c h e s C L E O II P a r tic le ID N e w T r a c k i n g C L E O III 2 c m B P S ilic o n b s H e - p r o p a n e K, K, / C L E O S C II.5 IR Q u a d s C s I S C R F 3. 5 c m B P 1 I R C r o s s i n g A n g l e 9 X 3 B u n c h e s