Spectroscopy and New Resonances at Belle

1. Spectroscopy and New Resonances at Belle B. Golob University of Ljubljana, Slovenia Belle Collaboration • Experimental environment • X(3872) quant. numbers • gg →Z(3930) -cc2’ • Y(3940) • X(3940) • Summary B. Golob, Belle Lake Louise Winter Inst., 2006

2. Experimental environment Mt. Tsukuba KEKB Belle u,d,s,c ~1 km in diameter > 1 fb-1/day (>1 M BB/day) Integrated luminosity ∫Ldt ~500 fb-1 on reson. 50 fb-1 off reson. ~550 M BB B Feb ‘06 May ‘99 KEKB asymmetric B factory Belle B e+ Υ(4s) e- u,d,s,c e+ g* e- 8 GeV e- 3.5 GeV e+ available data B. Golob, Belle Lake Louise Winter Inst., 2006

3. Observed by Belle 275M BB,hep-ex/0505037 275M BB,hep-ex/0505038 X(3872) 152M BB,PRL91,262001(2003) B± → K± gJ/y B± → K± p+p-J/y B± → K± cc1(gJ/y) calibration mode, p0 veto world average: M=3871.9±0.5 MeV/c2 y’ X(3872) no. of B’s in bins ofM(gJ/y) 13.6±4.4 evts.(4s) M=3872 MeV/c2 s=13 MeV/c2 M(p+p-l+l-)-M(l+l-) Br(B→XK) Br(X→p+p-J/y) = (1.31±0.24±0.13)x10-5 charmonium, DD*, tetraquarks...? E.S.Swanson,PLB588,189(2004) L.Maiani et al.,PRD71,014028(2005) C(X(3872))=+1 B. Golob, Belle Lake Louise Winter Inst., 2006

4. p+ X(3872) X(J/y, r) q l- l+ p- JPC=1++ p- X(J/y, r) q B K |cosq| p+ 275M BB,hep-ex/0505038 • X→gJ/y • ang. distrib. • M(p+p-) in X→p+p-J/y disfavor all of J=0,1,2 cc states except • 1++, 2++ • X→D0D0p0 ?? • 1++ →DD* S-wave • 2++ →DD* D-wave, • suppressed by • (q*)2L+1 angular distributions in B± → K± X(p+p-J/y) examples: expected JPC=0++ c2/nof=31/9 side band |cosq| c2/nof=5/9 X→ J/y r, S-wave B. Golob, Belle Lake Louise Winter Inst., 2006

5. X(3872) N=12.5±3.9 (>5) B→KD0D0p0/KD0D*0 M(D0D0p0) in B signal region preliminary Br(BK X)Br(XDD) =(1.6±0.4±0.3)10-4 M(D0D0p0) ≈ M(X) Br(XDD)/Br(X→p+p-J/y) =12±5 hard to accomodate with a 2++ state JPC(X(3872))=1++ B. Golob, Belle Lake Louise Winter Inst., 2006

6. 395fb-1,hep-ex/0512035 acc. to PRL e+ g D D g e- • un-tagged • D0→Kp, Kpp0, K3p D+→Kpp • pt(DD)<0.05 GeV/c 64±18 evts M=3929±5±2 MeV/c2 G=29±10±2 MeV M(DD)[GeV/c2] D side band Z ≡ cc2’ 23P2 cc Z(3930) q*: D,beam axis in gg frame acceptance corrected J=2 expect. c2/nof=1.9/9 J=0 expect. c2/nof=23.4/9 D side band 5.3s S.Godfrey,N.Isgur,PRD32,189 (1985) C.R.Münz,Nucl.Phys.A609,364 (1996) B. Golob, Belle Lake Louise Winter Inst., 2006

7. Y(3940) 275M BB, PRL94, 182002(2005) Dalitz plot for B→ KwJ/y M(Y)=3943±11±13 MeV G=87±22±26 MeV 58 ± 11 evts. >8s No. of B’s in bins of M(wJ/y) B± → K* J/y; K*→ K± w resonant structure? M2(J/yw) Br(B→YK) Br(Y→wJ/y)= (7.1±1.3±3.1) x10-5 M(J/yw) M2(Kw) radially excited P-wave cc? large Br(Y→wJ/y) cc-gluon hybrid? suppressed D(*)D(*) decays predicted M≥4.3 GeV F.E.Close,P.R.Page, Nucl.Phys.B443,233(1995) C.Banner et al., PRD56,7039(1997) B. Golob, Belle Lake Louise Winter Inst., 2006

8. X(3940) 357fb-1,hep-ex/0507019 subm. to PRL X(3940)→D(*)D ? reconstruct J/y + one D constrain Mrec(J/y D)=M(D(*)) s(Mrec(J/y))~10 MeV/c2 X e- e+ J/y Reconstruct J/y →l+l- recoil mass (mass of X): Mrec(J/y D)=M(D) 266±63 evts M~3936 MeV/c2 s(Mrec)~ 30 MeV/c2 Mrec(J/y D)=M(D*) 24.5±6.9 evts 5s 5s M=3943±6±6 MeV/c2 G<52 MeV @90% C.L. B. Golob, Belle Lake Louise Winter Inst., 2006

9. 357fb-1,hep-ex/0507019 subm. to PRL X(3940) inclusive/D*D tagged sample, common evts removed B>2(X→D*D) > 45% @90% C.L. B(X→D D) < 41% @90% C.L. B(X→J/y w) < 26% @90% C.L. no evidence for X(3940)→J/y w X(3940)≠Y(3940) several speculations on X(3940) nature, all pro’s and con’s; further experimental study (ang. distrib.) B. Golob, Belle Lake Louise Winter Inst., 2006

10. Summary • KEKBis also a great source of charm & cc states • Some expected, manyunexpected/puzzling observations/discoveries cc2’ DsJ Sc(2800) Y(3940) X(3872) PQ broad D** X(3940) understanding range of questions: existence? all properties as expected? what are they? anomalous properties? B. Golob, Belle Lake Louise Winter Inst., 2006