 Decays at CLEO Steve Blusk Syracuse University for the CLEO Collaboration Preview  Introduction  Measurements of B (  (nS)   +  - )  Electric Dipole Transitions   (1S)  ( c c ) + X  Summary Preview  Introduction  Measurements of B (  (nS)   +  - )  Electric Dipole Transitions   (1S)  ( c c ) + X  Summary ICHEP’04, Beijing, China Aug 16-22,2004

Bottomonium J PC  1 -- (bb) states couple to virtual photon   (1S)-  (3S) too light to form B mesons  ggg and qq decays dominant, but suppressed.  States are narrow !  EM and hadronic transitions to lower-lying bb states competitive   (4S)  BB; Weak Int. Physics n 2S+1 L J J=L+S Photon Transitions E1: |  L|=1,  S=0: M1:  L=0, |  S|=1:   E1 >>  M1 Hyperfine (spin-spin) splitting Spin-orbit 3 P J  3 P 0,1,2 CLEO III

Detector & Data Samples  (1S)  (2S)  (3S)  10 6 Analyses presented here make extensive use of the excellent CsI calorimeter, tracking and muon systems CsI: 6144 crystals (barrel only):  E /E ~ 4% at 100 MeV ~2.5% at 1 GeV Tracking

Measurement of B (  (nS)      )  Goal: Extract  tot. of  (nS).   tot <<  E beam  cannot be extracted by scanning the resonance.  Use:  tot =  ee / B ee =  ee / B  where B ll =B (  (nS)   +  - ); (assumes lepton universality)  B (  (nS)      ) also important for  (nS) EM & hadronic BF’s.  We actually measure:  Which is related to B  by:  (nS)      Event Selection  Exactly 2 back-to-back oppositely charged muons  50 MeV  (nS)  hadrons Event Selection  >2 charged tracks  For N trk <5: (E cc > 0.15E cm ) & (E cc <0.75E cm or E sh max <E beam )  E visible > 0.2E cm  (nS)      efficiency: (65.2±0.2)%  (nS)  hadrons efficiency: (97-98)% Background dominated by cascade decays: e.g.  (2S)   (1S)  0  0 /    (2S) : (2.9±1.5)%  (3S) : (2.2±0.7)% N sh < 2 N sh  2 M  /E beam  (2S)   (1S)X,  (1S)       (2S)       (2S) Data ICHEP ABS

B (%) Results  (1S)  (2S)  (3S) N  344,908 ± ± ± 2660   ± N had 18,957,575 ± ,838,270 ± 88034,641,369 ±  had ± ± ±.014 Interference corr B  (%) 2.49  0.02   0.03   0.07  0.10  tot (keV) 52.8 ± ± ± 2.1 PDG  tot (keV) 53.0 ± ± ± 3.4  (1S)   in good agreement with previous measurements  (2S),  (3S)   significantly larger than current world average values

Electromagnetic Transitions  Aim is to get precision measurements of masses and transition rates.  Tests of LQCD & effective theories, such as potential models or NRQCD.  We present results on Inclusive Analyses of E1 transitions:   (2S)   bJ (1P)   (3S)   bJ (1,2P)  Can be used to extract E1 matrix elements and extract relative importance of spin-orbit and tensor interactions. C. Davies, et al, PRL (2004)

Inclusive  (2S)   bJ (1P) e+e-e+e- hadrons    (2S)  Branching Fraction (%) Photon energy (MeV)   b0 (1P)3.75  0.12   0.19  0.42   b1 (1P)6.93  0.12   0.09  0.29   b2 (1P)7.24  0.11   0.08  0.30 Raw Background subtracted hadrons Preliminary Dominant Systematics B: Shower Simulation & Fitting E  : Calorimeter calibration

 (3S)  Branching Fraction (%) Photon energy (MeV)   b0 (2P)6.77  0.20   0.16  0.46   b1 (2P)14.54  0.18   0.07  0.25   b2 (2P)15.79  0.17   0.06  0.27   b0 (1P)0.30  0.04  Inclusive  (3S)   bJ (1,2P)  (2S)  b (1P J )   (1D J )  b (1P j )   (3S)   b (1P 0 )   (3S)   b (1P 2 )  +  (3S)   b (1P 1 )  +  b (1P J )   (1S)   (3S)   bJ (2P)  (3S)   bJ (1P)  E   MeV  Preliminary

Summary of  (2S)   bJ (1P) Results (Preliminary) EE EE B B  (2S)   b (1P 2 )  (2S)   b (1P 1 )  (2S)   b (1P 0 ) Gives quantitative information on the relative importance of spin-orbit & tensor forces

Summary of  (3S)   bJ (2P) Results (Preliminary) EE EE B B  (3S)   b (2P 2 )  (3S)   b (2P 1 )  (3S)   b (2P 0 )

Charmonium Production in  (1S) Decay  History: CDF observes J/ ,  (2S) ~10x, 50x too large.  Braaten & Fleming propose color-octet (CO) mechanism; J/  produced perturbatively in CO state and radiates a soft-gluon (non-perturbatively) to become a color-singlet (CS); fit to data.  Problems though: J/  polarization data from CDF, e + e -  J/  +X from BaBar & Belle, J/  at HERA. Suggestion by Cheung, Keung, & Yuan: If CO is important, the glue-rich decays of  should provide an excellent labortatory for studying the role of the CO mechanism in  production.  Distinct signatures in J/  momentum spectrum (peaking near endpoint). Li, Xie & Wang show that the Y(1S)  J/  +ccg may also be important (2 charm pairs) Li, Xie & Wang, PLB 482, 65 (2000) Cheung, Keung & Yuan, PRD (1996) B (  (1S)  J/  +X) 6.2x x10 -4 Momentum Spectrum SoftHard Previous CLEO measurement based on ~20 J/    events: B =(11±4)x10 -4 ICHEP ABS

Event Selection & Signals  Data Sample: 21.2x10 6  (1S) decays  Reconstruct J/      , e + e -  Backgrounds:  Radiative return: suppressed through N trk, E  max, and P ev miss requirements  Radiative Bhabha (ee only): veto events where either electron can form M(e + e - )<100 MeV.     cJ : Negligible after N trk and P ev miss requirements.  e + e -  J/  +X continuum: Estimated using  (4S) data and subtracted.  Efficiencies: ~40% (~50%) for J/    (J/   ee); small dependence on momentum, cos   (1S)  J/  +X e + e -  J/  +X below Y(4S)

 (1S)  J/  +X B (  (1S)  J/  +X)=(6.4±0.4±0.6)x10 -4  Spectrum much softer than CO prediction  Somewhat softer than CS prediction  Very different from continuum Continuum Background  (e + e -  J/  +X)=1.9±0.2(stat) pb BaBar  (e + e -  J/  +X)=2.52±0.21±0.21 pb, PRL87, (2001) Belle  (e + e -  J/  +X)=1.47±0.10±0.13 pb, PRL88, (2002) Normalization to  (1S) Data * Luminosity ratio * Phase space ratio: 0.78±0.13 BaBar

First Observations/Evidence  (1S)   (2S)+X  (1S)   cJ +X CO & CS both predict ~20%  c1,  c2 BF’s ~2x CO prediction  (4S) Continuum

Summary CLEO has the world’s largest sample of  (1S),  (2S), and  (3S) data sets  Precision measurements in (bb) spectroscopy (rates, masses) provides a unique laboratory for probing QCD.  Glue-rich environment is ideal for studying color-octet predictions Recent work also includes:  Searches/limits for M1 transitions (  b )  First observation of a  (1D) state (first new (bb) state in 20 years!)  Measurements of new hadronic transitions (e.g.,  b1,2 (2P)   (1S))  Searches for anomalous couplings Many other interesting topics are in the pipeline  Exclusive 2  and 4  transitions in  (3S) decays  New measurements of  ee for  (1S),  (2S),  (3S)   (1S,2S,3S)  Open Charm   (1S)  , K*K, etc (“  puzzle”)  Searches for LFV  …

Backup Slides

The Physics The  (1S)-  (3S) resonances are the QCD analogy of positronium - bb are bound by the QCD potential: e.g. V(r)= – 4/3  s /r + kr Large b quark mass  (v/c) 2 ~ 0.1  non-relativistic to 0 th order (In some models, relativistic corrections added to non-relativistic predictions) In much the same way that positronium allowed for a greater understanding of QED, the masses, splittings between states and the transition rates provide input into understanding QCD. Tests of lattice QCD  Important for flavor physics ! Test of effective theories, such as QCD potential models Coulomb-like behavior from 1-g exchange Long distance behavior, confining k~1 GeV/fm

  Electric Dipole Transitions After normalizing out the (2J+1)E  3 between different J’s, we obtain:  b (2P): (J=2) / (J=1) (J=0) / (J=1) (J=0) / (J=2) 1.00  0.01   0.02   0.02  0.09  b (1P): (J=2) / (J=1) (J=0) / (J=1) (J=0) / (J=2) 1.01  0.02   0.02   0.02  0.11  c (1P): (J=2) / (J=1) (J=0) / (J=1) (J=0) / (J=2) 1.50  0.02   0.01   0.01  0.05 In the non-relativistic limit, the E1 matrix element is spin independent.  In NR bb system, (v/c) 2 ~ 0.1  expect ratios ~ 1  NR corrections O (<20%) for J=0  Also shown are (cc), which show sizeable differences (v/c) 2 ~0.3; mixing between 2 3 S 1 and 1 3 D 1 states may also contribute. Comparison with various models  E1 = B (n i S  n f P)  tot (  (nS)) Using: Uses new CLEO  tot values We can extract  Relativistic corrections needed for (cc)  In (bb) system, NR calculations in reasonable agreement with data. o = predictions (non-relativistic) ▲ = spin-averaged predictions (relativistic) time

Spin-Orbit & Tensor Interactions Responsible for splitting the P states  3 P J Can express: M J=2 = M cog + a LS - 0.4a T M J=1 = M cog - a LS + 2a T M J=0 = M cog - 2a LS - 4a T where Spin-Orbit Coeff. Tensor Coeff. V 0 = static potential; V 2,3 = spin-dependent potentials (both model-dependent) Data on mass-splittings can be used to extract a LS and a T,  Experimentally, the mass splittings are most precisely determined using CLEO3CLEO2 r (1P) 0.57  0.01   0.02  0.02 r (2P) 0.58  0.01   0.01  0.01 Our results indicate that there is no difference between the different radial excitations of the P waves in (bb) system.

Search for  b in  (3S)   b (1S)  and  (2S)   b (1S)   (2S)   b (1S)   (3S)   b (1S)   b (2P J )   (1S)    (2S) Data  b (1P J )   (1S)  Hindered (n i  n f ) M1 transition suppressed by 1/m b 2 Large differences among models  (3S) Data  (3S)   b (2S)  (2S)   b (1S)  (3S)   b (1S) 

CUSBII (PRD46,1928(1992)) vs CLEOIII £  (3S) ~200/pb £  (3S) ~1300/pb   ~10% (poor segmentation of calorimeter)   ~60% Also it seems that they had worse energy resolution. We are very surprised that they claimed comparable accuracy to ours.  (3S)   b (2P J ) 

e + e -  J/  +X using on Y(4S) Data, p J/  >2 GeV

Y(1S) & Y(4S) Overlayed