1. Highlights from BESIII Stephen Lars Olsen, Seoul Nat’l Univ. YongPyong, Feb. 27, 2013

2. To Tiananmen Square (~10 km) BESIII BEPCII e+e+ e-e- 高能物理研究所 The Beijing Electron Positron Collider -- BEPCII --

3. 3 BEPCII storage rings Beam energy: 1.0 - 2.3 GeV Peak Luminosity: Design : 1×10 33 cm -2 s -1 Achieved : 0.65x10 33 cm -2 s -1 Beam energy measurement: Using Compton backscattering technique. Accuracy:  E beam /E beam ≈ 5  10 – 5   E beam ≈ 50 KeV @E beam ≈ m 

4. BESIII’s 1 st event

5. 5 Japan (1) Tokyo Univ. US (6) Univ. of Hawaii Univ. of Washington Carnegie Mellon Univ. Univ. of Minnesota Univ. of Rochester Univ. of Indiana Europe (12) Germany: Univ. of Bochum, Univ. of Giessen, GSI Univ. of Johannes Gutenberg Helmholtz Ins. In Mainz Russia: JINR Dubna; BINP Novosibirsk Italy: Univ. of Torino ， Frascati Lab Netherland ： KVI/Univ. of Groningen Sweden: Uppsala Univ. Turkey: Turkey Accelerator Center China(30) IHEP, CCAST, GUCAS, Shandong Univ., Univ. of Sci. and Tech. of China Zhejiang Univ., Huangshan Coll. Huazhong Normal Univ., Wuhan Univ. Zhengzhou Univ., Henan Normal Univ. Peking Univ., Tsinghua Univ., Zhongshan Univ.,Nankai Univ. Shanxi Univ., Sichuan Univ., Univ. of South China Hunan Univ., Liaoning Univ. Nanjing Univ., Nanjing Normal Univ. Guangxi Normal Univ., Guangxi Univ. Suzhou Univ., Hangzhou Normal Univ. Lanzhou Univ., Henan Sci. and Tech. Univ. Hong Kong Univ., Hong Kong Chinese Univ. Korea (1) Seoul Nat. Univ. Pakistan (2) Univ. of Punjab COMSAT CIIT ~300 members 52 institutions from 11 countries BESIII Collaboration

6. e + e - annihilations at 2.0 <E cm < 4.6 GeV E cm (GeV) NN thresh Charmonium DD thresh R-QCD XYZ mesons Light hadrons D s D s thresh _ _ _  c  c thresh _  - thresh h c  c  states cc v v v v Large and diverse suite of physics topics R-QCD

7. Physics program @ BESIII Light hadron physics -meson & baryon spectroscopy -multiquark states -threshold effects -glueballs & hybrids -two-photon physics -p & n form-factors Charmonium physics: - precision spectroscopy - transitions and decays QCD &  -physics: - precision R-measurement -  decays Charm physics : - semi-leptonic form factors - f D & f D s decay consts. - CKM matrix: V cd, V cs - D 0 -D 0 mixing and CPV - strong phases Precision mass measurements : -  mass  D 0, D + & D s masses  XYZ meson physics: -Y(4260)   h c & other decays - searches for new states …

8. BESIII data samples ≈1.2 billion (225M analyzed)

9. Physics program @ BESIII Light hadron physics -meson & baryon spectroscopy -multiquark states -threshold effects -glueballs & hybrids -two-photon physics -p & n form-factors Charmonium physics: - precision spectroscopy - transitions and decays QCD &  -physics: - precision R-measurement -  decays Charm physics : - semi-leptonic form factors - f D & f D s decay consts. - CKM matrix: V cd, V cs - D 0 -D 0 mixing and CPV - strong phases Precision mass measurements : -  mass  D 0, D + & D s masses  XYZ meson physics: -Y(4260)   h c decays - searches for new states - …,

10. Mesons near the pp threshold related to? _ BESII -- 10 years ago -- BESII PR L 91, 022001 (2002)

11. BESIII, in 2012, with 5x more data BESIII PR L 108, 112003 (2012) Partial Wave Analysis: -J PC = 0 -+ >6.8 σ better than other assignments -I=0 FSI (Juelich) improves the fit quality by ~7   - M=1832 -5 -33 ± 19 model MeV ≈2m p -40 MeV -  =13±20 -33 MeV; < 76 MeV - Bf(J/    X)×Bf(X  pp)= (9.0 -1.1 -5.0 ± 2.3 model )×10 -5  suggests Bf(X  pp)~large +19 +18 +11 +0.4 +1.5 J/    pp _ _ _

12. Some non-observations

13. A pp bound state (baryonium)? p npp deuteron: loosely bound 3-q & 3-q color singlets with M d =2m p -  baryonium: loosely bound 3-q & 3-q color singlets with M b =2m p -  ? attractive nuclear force attractive force? There is lots & lots of literature about this possibility

14. An old idea

15. Fermi & Yang in 1949 (7 years before p discovery): If NN potential is attractive, they could bind to form  -like states.

16. Expectation for pp bound state meson m p +m p above threshold: X  pp ~100% below-threshold: p and p annihilate to mesons I=0, J PC =0 -+ init. state: pp       ’ is common _ _ _ _ Phys. Rev. C 72, 015208 (2005) G.J. Ding and M.L.Yan Comm. Theor. Phys. 42, 844 (2004) C.S. Gao and S.L. Zhu

17. J/    X(1835)   (      ’ ) M(      ’) M=1833 MeV  70MeV m p +m p BESII PR L 95, 262001 (2005) BESII -- 8 years ago --

18. 18 X(1835) confirmed at BESIII (+ two new structures with M>2GeV) f 1 (1510) two new ones! J/             BESIII X(1835) ResonanceM( MeV/c 2 )  ( MeV/c 2 ) Stat.Sig. X(1835)1836.5±3.0 +5.6 -2.1 190.1±9.0 +38 -36 >20σ X(2120)2122.4±6.7 +4.7 -2.7 83±16 +31 -11 7.2σ X(2370)2376.3±8.7 +3.2 -4.3 83±17 +44 -6 6.4σ Bkg-subtracted; Eff.-corrected X(1835): same mass and J PC as the pp peak, but larger width _ consistent with 0 -+ X(1835) consistent with 0 -+ PRL 106, 072002 (2011 ) narrow!! X(1835)

19. What are these 2 new structures? PRD73,014516(2006) Y.Chen et al 0 -+ : 2560(35)(120) 2 ++ : 2390(30)(120) first distinct resonant structures observed above 2 GeV: - LQCD predicts that the lowest –lying -----pseudoscalar glueball: around 2.3 GeV -J/    ’     is a good decay channel - ----for finding 0 -+ glueballs. X(2120)/X(2370) possibilities: -pseudoscalar & tensor glueballs? -  /  excited states? Need spin-parity analyses PRD82,074026,2010 J.F. Liu, G.J. Ding and M.L.Yan PRD83:114007,2011 (J.S. Yu, Z.-F. Sun, X. Liu, Q. Zhao) way above threshold, but narrow (  <100 MeV)

20. Physics program @ BESIII Light hadron physics -meson & baryon spectroscopy -multiquark states -threshold effects -glueballs & hybrids -two-photon physics -p & n form-factors Charmonium physics: - precision spectroscopy - transitions and decays QCD &  -physics: - precision R-measurement -  decays Charm physics : - semi-leptonic form factors - f D & f D s decay consts. - CKM matrix: V cd, V cs - D 0 -D 0 mixing and CPV - strong phases Precision mass measurements : -  mass  D 0, D + & D s masses  XYZ meson physics: -Y(4260)   h c decays - searches for new states - …,

21. Precision charmonium mass of the  c  charmonium ground state   properties of the h c  most recently discovered charmonium state M1 transition  ’   c  first observation  ‘

22.  c (1S) The S-wave spin-singlet charmonium ground state, found in 1980 M &  measurements: -J/  radiative transitions: M ~ 2978.0 MeV,  ~ 10 MeV -  processes / B  K  c :M = 2983.1±1.0 MeV/,  = 31.3±1.9 MeV   pp, B decay  (1S, 2S)   c Mass width C.L.<0.0001 C.L.=0.0014 _

23.  ’   c,  c  exclusive decays M: 2984.4 ± 0.5 ± 0.6 MeV  : 30.5 ± 1.0 ± 0.9 MeV  : 2.35 ± 0.05 ± 0.04 rad Relative phase  values from each mode are consistent within 3 ,  use a common phase value in the simultaneous fit. interference with non-resonant background is significant!! KsK  K+KK+K  KsK3  2K2    BESIII PRL 108, 222002 (2012)

24. Comparison with previous  c results ‘ ‘ Theorists are happier with this value (earlier result -- ~117 MeV -- was too large for them) LQCD McNeile QWG2011 Masswidth BESIII Hyperfine splitting (BESIII alone):  M(1S) = 112.5 ± 0.8 MeV

25. hc(1P1)hc(1P1) Spin singlet P wave (S=0, L=1) Potential model: if non-zero P-wave spin-spin interaction,  M hf (1P) = M(h c ) - ≠0  where = [(M(  c0 )+3M(  c1 )+5M(  c2 )]/9,  CLEOc 1 st observed h c in ee   ’   0 h c, h c   c  M hf (1P)=0.08±0.18±0.12 MeV/c 2 Consistent with 1P hyperfine splitting = 0. Theoretical prediction: BF(  (2S)   0 h c ) = (0.4-1.3)×10 -4 BF(h c   c ) =48% (NRQCD) BF(h c   c ) =88% (PQCD) Kuang, PR D65 094024 (2002) BF(h c   c ) =38% Godfrey and Rosner, PR D66 014012(2002)

26. methods for studying the h c   only detect the  0  “inclusive” (compute M h c from kinematics) detect the  0 &   “E 1 -tagged” (compute M h c from kinematics) detect the  0,  & all  c  X i decay products  “exclusive” (compute M h c from 4-C kinematic fit) hadrons

27. 27  ’   0 h c, h c   c Mass = 3525.40±0.13±0.18 MeV/c 2 Width = 0.73±0.45±0.28 MeV <1.44 MeV @90% CLEOc: PRL 101 182003 (2008) Mass = 3525.28±0.19±0.12 MeV Width: fixed at 0.9 MeV Hyperfine mass splitting  M hf (1 1 P)= M(h c ) - BESIII: 0.10±0.13±0.18 MeV/c 2 CLEOc: 0.02±0.19±0.13 MeV/c 2 By combining inclusive results with E1-photon tagged results BF(  '   0 h c ) = (8.4±1.3±1.0) ×10 -4 Agrees with prediction from Kuang, BF(h c    c ) = (54.3±6.7±5.2)% Godfrey, Dude et al. inclusive E1 tagged BESIII BESIII: PRL 104 132002 (2010)

28.  ’   0 h c, h c   c,  c exclusive decays Simultaneous fit to  0 recoiling mass  2 /d.o.f. = 32/46 Mass = 3525.31 ± 0.11 ± 0.15 MeV/c 2 Width = 0.70 ± 0.28 ± 0.25 MeV consistent with BESIII E 1 -tagged results Summed distribution 832±35 evts. BESIII Preliminary 16 different  c decay channels

29. Sum of 16 of  C decay modes The  C lineshape in h c   C is not as distorted as in    c decays; the non-resonant interfering bkg is small (non-existent?). Ultimately, this channel will be best suited to determine  c resonance parameters. Background subtracted  c lineshape from    0 h c, h c   c yesterday’s search  today’s discovery  tomorrow’s calibration

30. Sum of 16 of  C decay modes The  C lineshape in h c   C is not as distorted as in    c decays; the non-resonant interfering bkg is small (non-existent?). Ultimately, this channel will be best suited to determine  c resonance parameters. Background subtracted  c lineshape from    0 h c, h c   c yesterday’s search  today’s discovery  tomorrow’s calibration

31.  ’   c ‘  c1  c2 ‘ cc 1 st observation BESIII

32. Physics program @ BESIII Light hadron physics -meson & baryon spectroscopy -multiquark states -threshold effects -glueballs & hybrids -two-photon physics -p & n form-factors Charmonium physics: - precision spectroscopy - transitions and decays QCD &  -physics: - precision R-measurement -  decays Charm physics : - semi-leptonic form factors - f D & f D s decay consts. - CKM matrix: V cd, V cs - D 0 -D 0 mixing and CPV - strong phases Precision mass measurements : -  mass  D 0, D + & D s masses  XYZ meson physics: -Y(4260)   h c decays - searches for new states - …,

33. Charmed meson physics at BESIII Tag a D meson by reconstructing the accompanying D ---and vice versa-- ”” produce a “beam” of D mesons _ e + e -   ”(3770)  DD _ In the CM: cm energy difference: beam-energy constr. mass “tag side” “signal side”

34. D - tag side σ≈2MeV

35. D +   + signal side  only one charged track  positively identified as a  +  no isolated photons ++

36. D +   + backgrounds (from MC) Background determined from data: N b = 48.9 ± 4.8 evts Preliminary 377±21 signal evts

37. f D determination from CKM fitter Preliminary

38. Compare with theory

39. or: |V cd |determination fromLQCD Preliminary

40. |V cd | results

41. D +  l + prospects  D +   + with current (2.9 fb -1 ) data - Larger signal Bf + larger bkg  comparable sensitivity  Ultimately D + (& D s )   + and  + with 20 fb -1 Strong challenges to LQCD

42. Physics program @ BESIII Light hadron physics -meson & baryon spectroscopy -multiquark states -threshold effects -glueballs & hybrids -two-photon physics -p & n form-factors Charmonium physics: - precision spectroscopy - transitions and decays QCD &  -physics: - precision R-measurement -  decays Charm physics : - semi-leptonic form factors - f D & f D s decay consts. - CKM matrix: V cd, V cs - D 0 -D 0 mixing and CPV - strong phases Precision mass measurements : -  mass  D 0, D + & D s masses  XYZ meson physics: -Y(4260)   h c decays - searches for new states - …,

43. Precision mass measurements mm lepton universality: Koide’s formula: PRD 28, 252 (1983) mD0mD0 is M X(3872) above or below m D 0 +m D* 0 ? factor of ~3000 disparity numerology? M X(3872) m D 0 + m D* 0

44. BEPCII beam energy monitor ExEx

45. BEPCII tunnel Shielding wall IR laser steerer Dipole

46. Validate at the  ’ peak

47. Results from a 5pb -1 “pilot” run

48. Data from 30.5 pb -1 Results: m  = 1776.?? +- ?? MeV will be open soon will be open soon ultimate goal, with ~100pb -1   m  ≤ ±0.1 MeV

49. Physics program @ BESIII Light hadron physics -meson & baryon spectroscopy -multiquark states -threshold effects -glueballs & hybrids -two-photon physics -p & n form-factors Charmonium physics: - precision spectroscopy - transitions and decays QCD &  -physics: - precision R-measurement -  decays Charm physics : - semi-leptonic form factors - f D & f D s decay consts. - CKM matrix: V cd, V cs - D 0 -D 0 mixing and CPV - strong phases Precision mass measurements : -  mass  D 0, D + & D s masses  XYZ meson physics: -Y(4260)   h c decays - searches for new states - …,

50. Y(4260) (& Y(4350)) studies @ BESIII 233 fb -1 Y(4260) BaBar PRL95, 142001 (2005) ~50pb

51. Y(4260) confirmed by Belle -32 -28 Belle PRL 99, 182004

52. Not seen in e + e -  hadrons  (Y 4260      J/  ) > 1.6MeV @ 90% CL X.H. Mo et al, PL B640, 182 (2006) BES data ~3nb  peak  Y(4260)  +   J/  pb Huge by charmonium standards J.Z.Bai et al (BES), PRL 88, 101802 (2006)  (e+e-  hadrons)  (e+e-   +  -) 4260 No sign of Y(4260)  D ( * ) D ( * )

53. Belle saw a curious      (nS) structure in the bottomonium system  (e+e-       nS ) from a cm energy scan  5S peak position Fitted parameters PDG(  5S ): Belle PRD 82, 091106 (2010)

54. This is a strong source of “Z b ” mesons M( Υ (2S)π) max M( Υ (3S)π) max M( Υ (1S)π) max “  (5S)”  (1S)  +  - “  (5S)”  (2S)  +  - “  (5S)”  (3S)  +  - Z b (10610) B B* b b _ B-B* “molecule”? _ PDG: M B + M B* = 10604.5  0.6 MeV  =15.5  2.4 MeV M=10608.1  1.7 MeV B* b b _ B*-B* “molecule”? _ M=10653.3  1.5 MeV  =14.0  2.8 MeV 2M B* = 10650.2  1.0 MeV ± Belle PRL 99, 182004 (2007) Z b (10650)

55. Is the Y(4260) a source of “Z c ” mesons? m D +m D* reflection? BESIII now has ~1300 Y(4260)      J/  events --& has just accumulated a similar sample of Y(4360)       ’ evts-- Belle PRL 99, 182004 (2007) ~300 Y(4260) evts 2 entries/evt ±

56. We expect to have lots of interesting results on the Y(4260) & Y(4360) for Yongpyong 2014 Please invite us again

57. Concluding remarks  BEPCII is operating near design luminosity & BESIII is performing at state-of-art levels  pp threshold peak in J/    pp confirmed; J PC established as 0 -+ ; M≈2m p -40 MeV  X(1835)       ’ in J/        ’ confirmed at the same mass & J PC  additional narrow (  ≈80 MeV)      ’ mass peaks seen at ~2120 & 2375 MeV  glueballs?  Precision measurements of  c and h c charmonium-state properties are made  interference with non-resonant bkg is significant  World’s largest sample ever of  ”  DD decays already collected  precision measurements of f D, |V cs | and |V cd | & strong phases in progress  corresponding high-statistics D s measurements are planned  a  -mass measurement with ~±100keV precision is underway  High statistics studies of the Y(4260) and Y(4360) are underway  Search for charged Z c “molecule-like” states  Excellent detector, excellent machine, interesting program of physics for the next 10 yrs _ _ _