Juen,7th,2006Mo Xiaohu1 Results from  ’ Decays at BESII Xiaohu Mo IHEP, Beijing for the BES Collaboration Charm2006: International Workshop on Tau-Charm Physics June 5-7, 2006, Beijing, China

Juen,7th,2006Mo Xiaohu2 14 M  ’ events  6.4pb –1  ’ con GeV  58M J/  GeV  27pb –1  ’’ GeV 3M 14 M 4M

Juen,7th,2006Mo Xiaohu3 1.12% rule and/or  puzzle 2.Phase between strong and EM 3.Form factor measurement

Juen,7th,2006Mo Xiaohu4 The “12% rule” M. Appelquist and H. D. Politzer, PRL34, 43 (1975) This is the famous (or notorious) “12% rule”.

Juen,7th,2006Mo Xiaohu5  Violation revealed by Mark-II, confirmed by BESI at higher sensitivity.  Extensively studied by BESII  VP mode:  , K *+ K - +c.c., K *0 K 0 +c.c.,  0,…  PP mode: K S K L, K + K -,  +  -  VT mode: K*K* 2,  f 2 ’,  a2,  f 2  3-body: pp  0, pp , pn  -, pn  +, …  Multi-body:  +  -  0 K + K -, 3(  +  - ), …  Radiative mode:  KK ,  “12% rule” and “  puzzle” K*K ρπ MARK-II

Juen,7th,2006Mo Xiaohu6 Two-body decay VP mode

Juen,7th,2006Mo Xiaohu7 BESII 229  0 s  +  -  0 BESII BESII: PLB619, 247 (2005) Very different from J/  3  ! J/  ’’ PWA  ’  VP

Juen,7th,2006Mo Xiaohu8  ’  VP K * (892) K +c.c. K*  K * 2 (1430) B.G. K* 0 9.6±4.2 Evt. 3.5  65.6±9.0 Evt. 11  Br ± (2.9±1.7±0.4)  10 –5 Br 0 (13.3±2.8±1.7)  10 –5 K*  K* 0 K * 2 (1430) B.G. BESII: PLB614, 37  ’ Large Isospin Violation Br 0 / Br ± = J/  Br 0 / Br ± =0.8±0.1

BESII : PLB614, 37 (2005); PRD73, (2006) CLEOc: PRL94, (2005) J/ ,  ’  VP mode BESII: B(  ’)(×10 -5 ) CLEOc: B(  ’)(×10 -5 ) PDG04/BESII/… B(J/  )(×10 -4 ) B(  ’)/B(J/  ) (%)  5.1±0.7± ±0.2234±260.13±0.03  (2150)  19.4± N/A +-0+-0 18.1±1.8± ±2.8200±90.92±0.11 K* + K - +c.c. 13.3±2.7± ±0.950±40.34±0.20 K* 0 K 0 +c.c. 2.9±1.7± ±0.342±42.6±0.6  ± ± ± ±1.2  ± ± ± ±3.4  ’ ±0.33N/A1.05±0.1818±16  <0.40N/A<0.064N/A  3.3±1.1± ± ± ±1.2  ’ 3.1±1.4±0.7N/A5.46± ±3.0  <3.1N/A23.5±2.7<0.53  ’ ±0.7N/A2.26±0.4314±11

Juen,7th,2006Mo Xiaohu10 Two-body decay PP mode

Juen,7th,2006Mo Xiaohu11 Bkg MC signal 14M ψ(2S) J/ ,  ’  PP: K S K L PRL 92, (2004) 58M J/ψ signal MC Bkg K* 0 K S +c.c. Ks mass sidebands PRD 69, (2004) B  ’  Ks K L = (5.24± 0.47 ± 0.48 )  10 – 5 B J/   Ks K L = (1.82 ± 0.04 ± 0.13 )  10 – 4

Juen,7th,2006Mo Xiaohu12 J/ ,  ’  PP: 12% rule BES, PRL 92, (2004) CLEO, hep-ex/ KK mode enhanced relative to the 12% rule. Pure EM mode  not enhanced, may be suppressed. J/    and  ’   are related by  ee of charmonia and  form factors.  ’ (10 -5 )J/  (10 -4 ) Q h (%) +–+– 0.8±0.8±0.2 ( CLEO ) 90% C.L. ) 1.47 ± 0.23 (PDG04) 5.4 ± % C.L. ) K+K–K+K– 6.3±0.6±0.3 ( CLEO )2.37 ± 0.31 (PDG04) 26.6 ± 4.6 KSKLKSKL 5.8±0.8±0.4 ( CLEO ) 5.24±0.47±0.48 ( BES ) 5.44 ± 0.54 (average) 1.82 ± 0.13 (BES04) 31.9 ± ± ± 3.7

Juen,7th,2006Mo Xiaohu13 † This value from DM2 only Suppressed!! 12 % rule  ’  V T VT mode B  ’  X (10 – 4 ) (BES-II) B J/  X (10 – 3 ) (PDG2002) Q h (%)  f ±0.41 ± ± ±1.5  a ±0.73 ± ± ±1.1 K * K * ±0.32 ± ± ±1.3  f 2 ' 0.44 ±0.12 ± ±0.21 † 3.6 ±1.5 PRD69(2004)072001

Juen,7th,2006Mo Xiaohu14 Three and multi-body decay

Juen,7th,2006Mo Xiaohu15  ’  3-body pp 0pp 0 pppp pn –pn – pn +pn + 921±40914±42 256± ±8.7 final states pp  are used for pp  0 (  ) Main BG. for BB' M f.s. : 1.pn  –  2.pn  –  0 3.pn  –  0  PRD71,072006(2005); hep-ex/

Juen,7th,2006Mo Xiaohu16 † MARKII:PRD29,804(1984); ‡ PDG04. Suppressed!!  ’  3-body mode B  ’  X (10 – 4 )B J/  X (10 – 3 )Q h (%) pn –pn – 2.45 ±0.11 ± ±0.17 †12.1 ±1.6 pn +pn ±0.12 ± ±0.17 †13.1 ±1.8 pp 0pp ±0.10 ± ±0.09 ‡12.1 ±1.9 pppp 0.58 ±0.11 ± ±0.18 ‡2.8 ±0.7 BESII: PRD71, (2005) BESII: hep-ex/ B(pp  0 ): B(pn  – ): B(pn  + )=1: (1.86±0.27) : (1.91±0.27 )  1:2:2 Yuan, Mo,Wang: PLB626, 95(2005)

Juen,7th,2006Mo Xiaohu17 Multi-body  ’ decays Some modes are suppressed, some are enhanced, while some others obey the 12% rule! CLEOc: PRD72, (2005) BESII, PRD73, (2006) CLEOc: PRL95, (2005)

Juen,7th,2006Mo Xiaohu18  ’  ,  KK   (958)  (1405)  c1   final states KK  final states BESII:Preliminary Lower mass region Higher mass region

Juen,7th,2006Mo Xiaohu19  ’  ,  KK  BESII : Preliminary

Juen,7th,2006Mo Xiaohu20 Facts:   ’  VP : suppressed   ’  PP : enhanced/supressed   ’  VT : suppressed  Multi-body : obey/sup  Radiative : enhanced/supressed Seems no obvious rule to categorize the suppressed, the enhanced, and the normal decay modes of J/  and  ’. Summary: “12%” rule

Juen,7th,2006Mo Xiaohu21 Phase between strong and EM

Juen,7th,2006Mo Xiaohu22 The phase study in e + e – experiment Phase Take the continuum contribution and its interference effect into consideration, we could determine not only the magnitude but also the sign of the phase. φ interference ±

Juen,7th,2006Mo Xiaohu23 The Relative Phase J/ψ Decays: 1. AP : 90 ° M. Suzuki, PRD63, (2001) 2. VP : (106 ±10) ° J. Jousset et al., PRD41, 1389 (1990) D. Coffman et al., PRD38, 2695 (1988) N. N. Achasov, talk at Hadron PP : (90 ±10) ° M. Suzuki, PRD60, (1999) 4. VV : (138 ±37) ° L. Köpke and N. Wermes, Phys. Rep. 74, 67 (1989) 5. NN : (89 ±15) ° R. Baldini et al., PLB444, 111 (1998) ψ’ Decays: 1. VP : φ = ﹣ 90 ° or 180 ° P. Wang et al., PRD69, (2004) 2. PP : φ = ( ﹣ 82 ±29)° or (+121 ±27)° J. Z. Bai et al., PRL92, (2004) φ Large | phase | ~ 90º Large phase ~ – 90º

Juen,7th,2006Mo Xiaohu24 B’ (π ﹢ π ﹣ ) and A’+B’ (K ﹢ K ﹣ ) known, K S K L is needed to extract the phase between A’ and B’. φ PP -Parametrization π ﹢ π ﹣ : E K ﹢ K ﹣ : (√3/2) M +E K S K L : (√3/2) M E.Haber and J.Perrier: Phys.Rev.D32, 2961 (1985) PP -Parameterization π ﹢ π ﹣ : (E+E C ) K ﹢ K ﹣ : (√3/2)M +(E+E C ) K S K L : (√3/2)M +Continuum Contribution Phase in PP mode

Juen,7th,2006Mo Xiaohu25 B (  ’  K S K L ) =5.8  10 – 5 Yuan, Wang, Mo: PLB567 (2003)73 K + K – &  +    inputs ; Input 1: DASP; Input 2: BESI ; Input 3: K + K – from BESI &  +   by form factor. –82°, – 80°+121°, +120° First measurement of the phase in  ’ decays! B (  ’  K S K L ) =5.24  10 – 5 Phase in PP mode

Juen,7th,2006Mo Xiaohu26 VT -Parameterization  f 2 : g(1  s g ) +e  a 2 : g(1  s g ) +e K * K * 2 : g(1  s g )  2 e (1  s e /2)  f 2 ' : g(1  s g )  2 e (1  s e ) A.Seiden,H.F.-W. Sadrozinski and E.Haber : Phys.Rev.D38, 824 (1988) Phase in VP and VT mode PP -Parameterization New data are available, only needed are more detailed analyses, which should take into account the interference effect and concrete experiment conditions

Juen,7th,2006Mo Xiaohu27 Form factor measurement (through EM or EM dominate process)

Juen,7th,2006Mo Xiaohu28 Wang, Mo, Yuan PLB557, 192(2003)  ’  VP or PP Electromagnetic process For data on top of resonance, both resonance and continuum amplitudes are need to be considered, which may have comparable magnitudes.

Juen,7th,2006Mo Xiaohu29  ’  VP @3.773GeV  

Juen,7th,2006Mo Xiaohu30  ’  VP and PP BESII: PRD70, (2004) CLEOc:

Juen,7th,2006Mo Xiaohu31 Form Factor Measurement A: PLB425(1998)365 B: hep-ph/ F(  +   ) F(K + K – )

Juen,7th,2006Mo Xiaohu32 Results about phase:   ’  PP :  80° or  120° [Experiment]   ’  VP : around  90° [Phenomenology]   ’  VT : needs further analysis  Multi-body : needs further analysis Summary: phase and form factor More and accurate results are needed both experimental and theoretical Efforts should be made Results about from factor:  VP mode:  0, ,  [BESII]  PP mode: K + K –,  +   [CLEOc]

Juen,7th,2006Mo Xiaohu33 Problems and Prospects: problems Getting it all right is a big challenge. And big challenges are worthy of big effects. E.S.Swanson, “The New Heavy Mesons, A Status Report”

Juen,7th,2006Mo Xiaohu34 Many new states have been discovered :  X(3872), X(3940), Y(3940), Y(4260), Z(3939)  D s (2317), D s (2460), D s (2630) Large data samples are expected in near future :  CLEOc : 30M  ’ planed to be taken this autumn  BESIII: planed cm –1 s –1, largest charmonium and charmed sample Problems and Prospect: Prospects In any case there is rich future of interesting results ahead of us. After all, a big surprise might just be around the corner  A.Stahl,“Physics with Tau Leptons ”

Juen,7th,2006Mo Xiaohu35 Thanks a lot ! 谢谢 !