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CLEOIII Upsilon results In principle, includes: CLEO-III dipion transitions between vectors –Complements CLEO05 results on transitions between L=1 P-states.

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Presentation on theme: "CLEOIII Upsilon results In principle, includes: CLEO-III dipion transitions between vectors –Complements CLEO05 results on transitions between L=1 P-states."— Presentation transcript:

1 CLEOIII Upsilon results In principle, includes: CLEO-III dipion transitions between vectors –Complements CLEO05 results on transitions between L=1 P-states High-precision measurement of dielectronic width of Y(1S), (2S) (3S) Many radiative results: –Observation of exclusives already presented:  –Upper limits on  and  ’ modes –UL on multibody modes (>=4 charged tracks) –Comparison of inclusive quark/gluon production in radiative decays of Y vs. qq+photon (ISR)

2 CLEOIII  CLEAN signals, angular analysis underway.

3 Dipion transitions Renewed interest in `double-bump’ structure in (3S)   (1S) following BaBar observation of 4S   (nS) Goal: spin/parity analysis across invariant mass to determine whether low-mass bump is sigma 0 – if not, what is it?

4 Exclusives: Multibody modes Exclusive radiative events  ‘bumps’ in the inclusive (scaled to E beam ) photon spectrum (assume narrow recoil object) We perform a series of fits to the inclusive  photon spectra as a function of E  in order to set an E  -dependent upper limit on these radiative events. Nota bene : ‘bumps’ in the inclusive photon spectra can also be caused by continuum threshold effects (ccbar, e.g.)

5 * → +,  → 4  MC An example, albeit exaggerated, of signal... (10 -2 )

6 Method (Fitting  Spectrum) We fit each step to a Gaussian+Chebyshev polynomial Step along the photon spectra with the Gaussian mean Fix Gaussian sigma at each step to be the detector resolution (~1% @ 5 GeV) Looking for narrow resonances so the measured photon energy dist. should be Gaussian with Gaussian width  E.

7 Efficiencies ( * → +,  → ?) 44 59  2%2p2K  0 50  5%480480 60  2% 4K 50  2%2  2K  0 53  2%66 74  3% 4p 67  2%420420 59  1% 6K 68  4% 2p2  62  3%4K2  0 49  2% 6p 52  4% 2p2K 56  2%4p2  0 63  2% 2  2K53  3%2p2  2  0 63  5% 4  0 60  2%2p2K2  0 57  2% 4K  0 48  2%2  2K2  0 54  3% 4p  0 65  2%440440 57  2% 2p2  0 54  5%460460 60  2% Worst  Phase Space High Mult.

8 All limits on the order of 10 -4

9 Embed signals at a given level into data. We then apply our procedure to the resulting spectra We construct all signals above our upper limit floor (~10 -4 ) in our accessible recoil mass range In/Out and Sensitivity Check

10 A( M  )+1.645*  A ( M  )

11 dN/d( A/  A )(<  (1S)) A/  A Check of pulls: Continuum data

12 Results Our sensitivity is of order 10 -4 across all accessible values of M  Above the threshold for any known B((1S) → +pseudoscalar, pseudoscalarh + h - h + h - +neutrals) We measure for all M  : B((1S) → +,4 charged tracks) < 1.05 x 10 -3 B((2S) → +,4 charged tracks) < 1.65 x 10 -3 B((3S) → +,4 charged tracks) < 5.70 x 10 -3

13 Results (2) Restricting M  to 1.5 GeV < M  < 5.0 GeV we measure: B((1S) → +,4 charged tracks) < 1.82 x 10 -4 B((2S) → +,4 charged tracks) < 1.69 x 10 -4 B((3S) → +,4 charged tracks) < 3.00 x 10 -4 We report these upper limits as a function of recoiling mass M  (see conf. Paper) B.R.’s are all ~10 -4. N.B. Not in conflict with any observed two-body radiative decays to-date (due to 4-charged track requirement here)

14 Many modes! Dedicated search for 1S   and 1S   ’; Observed in J/psi decay at 10 -4 and 4.7x10 -4 level

15 Only upper limits quoted at this time… Suggests dedicated search for (1S)   c ?

16 Quarks v. Gluons 1981 (CESR): e + e - collisions (E CM ~ 10 GeV) produce  ;   ggg allows high-statistics study of gluon fragmentation Isolate gluons: ggg decay of  Isolate quarks: fragmentation 1984 Find: more baryons/event in ggg decay than Weakness: 3 partons (ggg) vs. 2 partons ( ) 3 strings (ggg) vs. 1 string ( ) Solution: decay of  vs. decay of continuum

17 e + e - Z 0 (LEP) Y(1S)  3gluons, but also 2-gluon source: e + e - (CLEO) e + e -  (1S) (CLEO) Z0Z0

18 Data Sets Data SetLuminosity (1/fb)E CM (GeV) 1S1.199.46 2S1.0710.02 3S1.4210.36 4S5.5210.58 Below 4S2.1010.55 Note that for 2S and 3S have not corrected for cascades:  (2S)   (1S) + X  (3S)   (2S) + X  (3S)   (1S) + X Are included as consistency checks, but have subtractions and corrections that have not been included.

19 Method: vs. Bin according to particle momentum Count N(Baryon) per bin and normalize to hadronic event count Enhancement is: Continuum-subtracted Resonance Yield Continuum Yield Enhancement = 1.0  Particle is produced as often on resonance as on continuum

20 Method: vs. Bin particle yield recoiling against high-E photon according to tagged photon momentum Count N(Baryon) per bin and normalize to photon count in that bin Enhancement is: Continuum-subtracted Resonance Yield Continuum Yield Enhancement = 1.0  Particle is produced as often on resonance as on continuum

21 Λ p p φ Detector and Generator Level: ggg  manageable bias; use correction factor where appropriate; discrepancy in/out used for systematics

22 Successfully reproduce CLEO84 indications of baryon enhancement in 1S (ggg) vs. CO ( ) fragmentation Comparison of baryon production in 1S ggγ vs. e + e - (comparing two gluon to two quark fragmentation) -1S gg baryons shows much reduced enhancement relative to baryons -Effect not reproduced in JETSET MC Proton  f 2 results Ggg/qqbarGgγ/qqbargammaRatio p1.30 ± 0.011.10 ± 0.02~ 1.2 Antip1.33 ± 0.011.19 ± 0.03~1.1 Λ2.56 ± 0.021.97 ± 0.03~1.3 φ0.85 ± 0.031.1 ± 0.3~0.8 f2f2 0.66 ± 0.041.4 ± 0.9~0.5

23 Deuteron Production (Preliminary) B(1S  (ggg+gg   d+X= 2.86(0.30)x10 -5 Per event enhancement of deuteron production in gluons vs. quarks ~12.0(2.0). Also: note 1S  psi >> continuum  psi

24 Summary Radiative decays (in general) continue to be more elusive than for J/psi Baryon coupling to 3-gluons confirmed (even larger for deuterons!); enhancement in 2-gluons mitigated. Ramping down these efforts (CLEO-III  CLEOc) Future improvements/results hopefully to emerge from B-factories with dedicated Upsilon running Thanks to everyone who did the work!

25 Reproducing CLEO84 indications of baryon enhancement in 1S (ggg) vs. CO ( ) fragmentation New comparison of baryon production in 1S ggγ vs. e + e - comparing two gluon to two quark fragmentation -First time such a comparison has been made Essential results: -1S gg baryons shows much reduced enhancement relative to baryons -Effect not reproduced in JETSET MC Additional cross-checks (2S, 3S, comparison with mesons) included Overview

26 p and p: 2S/3S data corrected Data Results: ggg

27 Λ: 2S corrected Data Results: ggγ

28 Method (Extracting Limit) Plot the gaussian area A(x  ) from fits to inclusive photon spectra Convert into an upper limit contour with height=A(x  )+1.645* A (x  )  A (x  ) is the Gaussian fit sigma Negative points → 1.645* A (x  )

29 Divide on-resonance fits by efficiency corrected number of (1S), (2S) and (3S) events (-1 events ) Divide off-resonance fits by luminosity of off-resonance running and derive xsct UL’s Note: +f 2 (1270) will not show up in this analysis since B (f 2  4 tracks) is approximately 3% B (  (1S)  + ,  +  - ,  +  -  0 ) << 10 -4 The M  -Dependent Upper Limits

30 CHECK OF PULL DISTRIBUTIONS

31 Fragmentation Models Simplistically there are two models: Parton vs. String Parton: g or q radiates a new particle String: g and q are connected by a string (gluon). Particles move apart; string stretches and breaks; forms new particles String model is what is in JetSet MC ( CLEO: Jetset 7.4 PYTHIA ) Parameters tuned to √s = 90 GeV LEP Data e+e+ e-e- q

32 Data Results Show data and detector level MC enhancements for both ggg and ggγ “Corrected” data and generator level MC enhancements for those with a low CL fit. Systematic errors have been introduced based on the correction factor.

33 Λ p p φ f 2 1 Data Results: Momentum-Integrated Λ p p φ f 2 1


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