CLEOc and CESRc A New Frontier of Electroweak

CLEO-c and CESR-c: A New Frontier of Electroweak And QCD Physics CLEO-c Do. Do, Do K- + K+ K- + Kamal Benslama Seminar at the University of Montreal November 14, 2002 CESR-c

The CLEO Collaboration • Membership: • ~20 Institutions • ~155 physicists • ~1/2 DOE, 1/2 NSF • Currently expanding… • Publication history 1980 • ~320 papers • diverse physics: Albany Caltech CMU Cornell Florida Harvard Illinois Kansas Minnesota Ohio State Oklahoma Purdue Rochester SLAC SMU UCSD UCSB Syracuse Vanderbilt Wayne State

CESR

The CESR Storage Ring

The Storage Ring

CESR and CLEO u. Symmetric e+e- accelerator at or near (4 S) (PB ~ 300 Me. V/ c) the (4 S): e+e- (4 S) BB ( ~ 1 nb) e+e- qq, (q = u, d, c, s) ( ~ 3 nb) u. On 3 running at OFF (4 S) for continuum bkg subtraction u 1/ u. CLEO III collected ON: 6. 9 fb-1 OFF: 2. 3 fb-1

What is CESR-c and CLEO-c ? • Modify for low-energy operation: add wigglers for transverse cooling • Expected machine performance: One day scan of the ’: (1/29/02) Ecm L (1032 cm-2 s-1) 3. 1 Ge. V 2. 0 3. 77 Ge. V 3. 0 4. 1 Ge. V 3. 6 • Ebeam ~ 1. 2 Me. V at J/

CLEO III Detector CLEO-c Detector 93% of 4 p/p = 0. 35% @1 Ge. V d. E/dx: 5. 7% @min. I 83% of 4 87% Kaon ID with 0. 2% fake @0. 9 Ge. V 1. 5 T now, . . . 1. 0 T later 93% of 4 E/E = 2% @1 Ge. V = 4% @100 Me. V Trigger: Tracks & Showers Pipelined Latency = 2. 5 ms Data Acquisition: Event size = 25 k. B Thruput < 6 MB/s 85% of 4 For p>1 Ge. V

Cleo. III Tracking u Silicon (r = 2 - 12 cm) v 4 Layers, double sided v Suffering from rad damage u Drift Chamber (DR) (r = 12 – 82 cm) v 47 anode layers, 9796 cells v Inner part axial, outer part all stereo

Central Drift Chamber Average hit resolution 85 m Sweet spot ~ 55 -65 m • D K mass resolution ~ 5. 5 Me. V • Ks mass resolution ~ 3. 1 Me. V • p/p = 0. 35% @1 Ge. V • d. E/dx: 5. 7% @min. I

d. E/dx in the Drift Chamber • Cleo. III d. E/dx vs Momentum showing the , K and p bands. • The K/ separation from d. E/dx, in standard deviations.

Inner Tracking (2 < r < 12 cm) • Now: 4 Layer Silicon Detector • Double sided wafers, • 125000 channels • 1. 6% X 0 thickness • early radiation damage: Layers 1 & 2 rf eff • Proposed: 6 layer drift chamber • all stereo ( 10 -150 tilt) • 300 channels: smaller evt size • 1. 1% inner wall + 0. 1% gas • improves p/p (less material) • worsens z 0 (stereo) • preserves mass resolution • no effect on pattern recognition • build from spare parts

(rad) Silicon Radiation Damage • Efficiency losses exhibit wafer geometry, not detector geometry. • rphi side only. Z side so far shows no eff loss.

Wire vertex Chamber

RICH Detector

RICH u. Thinnest (19 cm) <0. 12% X 0 u. Proximity u. Solid Focusing Radiator (Li. F) v 45 o saw tooth outer face (40%) v. Rest flat radiator u 15. 7 cm N Expansion Gap u. MWPC photon detector u. Photosensitive gas = TEA (Triethylamine) abs=0. 5 mm, <165 nm u 3 s K/p separation at 2. 65 Ge. V/c Performance with Bhabhas (only RICH tracking): single resolution Flat radiator N resolution/track 14. 0 mrad 10. 2 5. 3 mrad Sawtooth radiator 12. 2 mrad 12. 0 4. 2 mrad

Cherenkov Images Flat radiators Sawtooth

The RICH Smiles + e e

PID using the RICH • Likelihoods are defined as where CB line shape (Gaussian with power law tail on the high side) - constant 2 K 2 = -2 log(LK/L ) • Likelihood method folds in photon count and Cherenkov angle measurement together

Number of events Efficiency vs fakes study K K m. D 0(Ge. V)/c 2 • cut on 2 K 2 • fit m(D 0) 2 K 2 x

Cs. I Calorimeter • 93% solid angle coverage - uniform resolution in barrel & E. C. • E/E = 4% @ 100 Me. V 2% @ 1 Ge. V • ~5. 5 Me. V 0 mass resolution

Typical Hadronic Event (From online event display)

Look What RICH did to our Data !

CLEOIII Rare B Analysis u Signal characteristics: v. Two stiff back-to-back particles v. Simple, robust analysis. v. Statistics limited, not systematics u Backgrounds: v. Entirely from “continuum” v. Continuum background characterized by event shape variables

Continuum Background Continuum occasionally produces high momentum, back-to-back, 48% u 35%K , 17%KK. , 75% from , , u Roughly 25% from u Primary handle is in global event shape characteristics Signal Spherical event Shape Continuum 2 -jets Structure

Analyses Strategy Study backgrounds (using Monte and OFF-resonance data) Carlo PS: u I would prefer Neural Network Monte Carlo Experiments: Study possible biases u Apply the fit to data tinu Maximum likelihood fit con u nal Reconstructions variables sig u um u

Reconstruction Variables v. Beam constrained mass v. Energy difference ~ 2. 5 Me. V (3. 0 Me. V if p 0 ) Resolution is mode dependent, but generally ~ 20 -25 Me. V ( 2 worse if p 0 ) vd. E/dx v. RICH

Reconstruction Variables Signal is isotropic, continuum is jetty Use shape variables v. Sphericity angle v. R 2 (Fox Wolfram moment) v. Momentum flow in nine cones around the sphericity axis Combine the variables in a Fisher discriminant

Maximum Likelihood Method and are the yields to be determined v PDF shapes for signal are determined from MC v PDF shapes for continuum are determined from OFF-resonance data

Maximum Likelihood Fit u Fit variables: u Fit component fractions: u Outputs: plus background, at the maximum of the Likelihood function. Efficiency: Use of Maximum Likelihood fit doubles the efficiency of the analysis compared to a normal counting analysis u u Systematics: All shapes are systematically varied to study effects. u Correlations: typically at few % level, except - where kinematics leads to ~ 20% correlation.

How well does CLEO III work? 1 st results from CLEO III data at Lepton-photon 2001 Yield BR(B K )(x 10 -6) B K CLEOIII CLEO(1999) Good agreement: between CLEOIII & CLEO II & with Ba. Bar/Belle.

FINAL Re sults VERY Soon

The CLEO-c Program 2 0 0 2 Prologue: Upsilons ~1 -2 fb-1 ea. 2 0 0 3 Act I: (3770) -- 3 fb-1 30 M events, 6 M tagged D decays 2 0 0 4 Act II: √s ~ 4100 -- 3 fb-1 1. 5 M Ds. Ds, 0. 3 M tagged Ds decays 2 0 0 5 Y(1 S) , Y(2 S), Y(3 S)… Spectroscopy, Matrix Elements, ee 10 -20 times existing world’s data (310 times MARK III) (480 times MARK III, 130 times BES II ) Act III: (3100) -- 1 fb-1 1 Billion J/ decays (170 times MARK III 20 times BES II)

Why run on threshold Resonances ? • Charm events produced at threshold are extremely clean • Large , low multiplicity • Pure initial state: no fragmentation • Signal/Background is optimum at threshold • Double tag events are pristine –These events are key to making absolute branching fraction measurements • Neutrino reconstruction is clean • Quantum coherence aids D mixing and CP violation studies A typical Y(4 S) event:

Tagging Technique • Pure DD or Ds. Ds production Many high branching ratios (~1 -10%) High reconstruction eff 6 M D tags Two chances 300 K Ds tags high net efficiency ~20% ! D K tag. S/B ~ 5000 Beam constrained mass Ds KK tag. S/B ~ 100

Why CLEO-c ? Why Now ? • We expect great advances in flavor and electroweak physics during the next decade: – Tevatron (CDF, D 0, BTe. V, CKM). – B-Factories (Ba. Bar, Belle). – LHC (CMS, ATLAS, LHC-b). – Linear Collider (? ). • What could CLEO-c possibly have to offer this program? To score nice goals we Absolutely need an excellent player who can make the Perfect passes at the perfect time CLEO-c

Precision Standard Model Tests Absolute hadronic charm branching ratios with 12% errors. f. D+ and f. Ds at ~2% level. Semileptonic decay form-factors (few % accuracy). Contribution to CKM Measurements

Absolute Branching Ratios ~ Zero background in hadronic modes Set absolute scale for all heavy quark meas. Decay Mode PDG 2000 ( B/B %) D 0 K 2. 4 D+ K Ds f 7. 2 25 CLEOc ( B/B %) 0. 5 1. 9

The importance of absolute Charm BRs Vcb from zero recoil in B D* + CLEO LP 01 Stat: 3. 1% Sys 4. 3% theory 4. 6% Dominant Sys: slow, form factors & B(D K ) d. B/B=1. 3%

Decay Constants: |f. D|2 |VCKM|2 Ds m t (Now: ± 35%) Br(Ds m+ D m KLm t (Now: ± 100%)

Importance of measuring f. D & f. Ds: Vtd & Vts �� 1. 8% ~15% (lattice) 1 ~5% (lattice) Lattice predicts f. B/f. D & f. Bs/f. Ds with small errors if precision measurements of f. D & f. Ds existed (they do not) could substitute in above ratios to obtain precision estimates of f. B & f. Bs and hence precision determinations of Vtd and Vts Similarly f. D/f. Ds checks f. B/f. Bs

Comparison between B factories & CLEO-C CLEO-c 3 fb-1 Current Statistics limited abcdefghi Ba. Bar 400 fb-1 Systematics & Background limited

Semileptonic Form Factors. |VCKM|2 |f(q 2)|2 Absolute magnitude & shape of form factors is a great test of theory. B i. e. HQET D b c u d l l 1) Measure D form factor in D l (CLEO-c): Calibrate LQCD to 1%. 2) Extract Vub at Ba. Bar/Belle using calibrated LQCD calc. of B form factor. 3) Precise (5%) Vub is a vital CKM cross check of sin 2. 4) Absolute rate gives direct measurements of Vcd and Vcs.

Semileptonic Decays |VCKM|2 |f(q 2)|2 Low Bkg! U = Emiss - Pmiss Decay Mode PDG 2000 ( B/B %) CLEOc ( B/B %) D 0 Kl 5 D 0 l 16 D+ l 48 Ds fl 25 Plus vector modes. . . 1. 6 1. 7 1. 8 2. 8

Semileptonic d. B/B, Vcd, & Vcs D 0 l D 0 Kl PDG CLEOc Vcs /Vcs = 1. 6% (now: 11%) Vcd /Vcd = 1. 7% (now: 7%) Use CLEO-c validated lattice + B factory B r/ / /lv for ultra precise Vub

How can CLEO-c Contribute to CKM Measurements ? An illustration using a variant of the 95% Scan method. Allowed regions of the - plane using: • current experimental results and • conservative theoritical uncertainties Allowed regions of the - plane using: • current experimental results and • theoritical uncertainties of O(1%) • 2% decay constants and 3% semileptonic form factors

CLEO-c: Probes of new Physics Mixing sensitivity at the 1% level. CP violation sensitivity at the 1 -2% level. • Rare Decays. Sensitivity: 10 -6

Charm Mixing K- e+e ” D 0 D 0 + Quantum coherence + K- Ratio of Rates: K- NO DCSD + K+ To 1 st order, where x = M/ y = /2

CP Violation K+ At the (3770) K e+e ” D 0 D 0 JPC = 1 e e+ i. e. CP+ + Suppose both D 0’s decay to CP eigestates f 1 and f 2: These can NOT have the same CP : CP(f 1 f 2) = CP(f 1) CP(f 2) (-1)l = CP- + Ex: - (since l = 1) Observing this is evidence of CP

Compare to B Factories Statistics limited. Systematics & background limited.

Probing QCD • and Spectroscopy –Masses, spin fine structure –Leptonic widths for S-states. Calibrate and test theoretical tech. –EM transition form factors • run on resonances winter ’ 01 -summer’ 02 • ~ 4 fb-1 total Uncover new states of matter Glueballs G=|gg Hybrids H=|gqq Study fundamental states of theory Requires detailed understanding of ordinary hadron spectrum in 1. 5 -2. 5 Ge. V mass range.

Gluonic Matter • Gluons carry color charge: should bind! • But, like Elvis, glueballs have been sighted too many times without confirmation. . • CLEO-c: find it or debunk it! huge data set modern detector 95% solid angle coverage • Radiative decays are ideal glue factory: c 1 c X • perfect initial state • perfect tag • glue pair in color isosinglet • CLEO-c: 109 J/ ~60 M J/ X • Partial Wave analysis • Absolute BF’s: , KK, pp, , …

The dubious life of the f. J(2220) (A case study) Now you see it… MARKIII (1986) BES (1996)

Now you don’t… ? ? Crystal barrel: pp LEAR 1998 … or do you? L 3 1997 … or don’t you? OPAL 1998 2 L 3 Signal 2 MKK 3 3

f. J(2220) in CLEO-c?

f. J(2220) in CLEO-c? BES CLEO-C + 74 32000 18 13000 K+ K- 46 18600 KS KS 23 5300 pp 32 8500 – 5000 CLEO-c has corroborating checks: 2 Two Photon Data: f. J 2220 3 Upsilonium Data: (1 S): Tens of events – CLEO II: B f. J /KSKS < 2. 5(1. 3) e. V – CLEO III: sub-e. V sensitivity

Inclusive Spectrum J/ X 10 -4 sensitivity for narrow resonance Eg: ~25% efficient for f. J(2220) Suppress hadronic bkg: J/ X

Additional topics • ’ spectroscopy (10 8 decays) ’chc… • t+t at threshold (0. 25 fb-1) • measure mt to ± 0. 1 Me. V • heavy lepton, exotics searches Likely to be added to run plan - • Lc. Lc at threshold (1 fb-1) • calibrate absolute BR(Lc p. K ) • R= (e+e- hadrons)/ (e+e- m+m-) • spot checks If time permits

The CLEO-c Program: Summary • Huge data set • 20 -500 times bigger than previous experiment • Modern and understood detector • Experienced Collaboration • Powerful physics case • Precision flavor physics • Nonperturbative QCD • Probe for New Physics • Very small and well-controlled backgrounds • Very small and well-understood systematic errors • A large number of and wide variety of precision measurements to challenge and validate theory

CLEO-c Physics Impact • CLEO-C workshop (May 2001) : successful ~120 participants, 60 non-CLEO • Snowmass working groups E 2/P 5 : acclaimed CLEO-c • HEPAP endorsed CLEO-c • CESR/CLEO Program Advisory Committee Sept 28 Endorsed CLEO-c • Proposal submission to NSF was on October 15, 2001 • Site visit on Jan/Feb 2002: Endorsed CLEO-c • Science Board March 2002, • Expect approval shortly thereafter • See http: //www. lns. cornell. edu/CLEO-C/ for project description

Invitation CLEO-c CESR-c If interested in CLEO-c program you are more than welcome to join my ex-colleagues. They have room for you ! More information is available in CLEO Web page: www. lns. cornell. edu/CLEO-c Contact person: spoke@mail. lns. cornell. edu

Glueball Spectrum