Hadron Spectroscopy CLAS g12

Transcription

1 Hadron Spectroscopy CLAS g12 D. P. Weygand High Energy (E γ > 4.4 GeV) Luminosity: 27 pb -1 Total Integrated Luminosity: 68 pb -1

2 Topics Meson Spectroscopy γp π + π + π (n) See C. Bookwalter γp ηπ ++ γp (φη)p γp (φπ 0 )p Cascade, Exotic Baryon and N* Spectroscopy γp θ + K π + θ + K + n γp K + K + X γp φ(ωp) e + e - ρ ω Interference See following talk, D. Djalali π 0, η, η e + e γ D.P. Weygand Hadron 2011 June 16,

3 E events/1997 PRL 81, 5760 (1998) PRD 65, (2002) D.P. Weygand Hadron 2011 June 16,

4 COMPASS CERN-SPS fixed target 2004: 2 days, 190 GeVπ - beam Pb target D.P. Weygand Hadron 2011 June 16,

5 COMPASS CERN-SPS fixed target 2004: 2 days, 190 GeVπ - beam Pb target D.P. Weygand Hadron 2011 June 16,

6 COMPASS CERN-SPS fixed target 2004: 2 days, 190 GeVπ - beam Pb target D.P. Weygand Hadron 2011 June 16,

7 COMPASS CERN-SPS fixed target 2004: 2 days, 190 GeVπ - beam Pb target J PC = 1 -+ D.P. Weygand Hadron 2011 June 16,

8 Why photoproduction? Isgur & Paton Phys. Rev. Lett. 54, (1985) D.P. Weygand Hadron 2011 June 16,

9 Cebaf Large Acceptance Spectrometer Particle Detection in CLAS D.P. Weygand Hadron 2011 June 16,

10 Cebaf Large Acceptance Spectrometer Particle Detection in CLAS D.P. Weygand Hadron 2011 June 16,

11 CLAS/g6 c (Nozar et al.). Phys.Rev.Lett. 102 (2009) D.P. Weygand Hadron 2011 June 16,

12 g12 Craig Bookwalter, Paul Eugenio FSU γp π + π + π n J PC =1 ++ D.P. Weygand Hadron 2011 June 16,

13 γp π + π + π n J PC =2 ++ D.P. Weygand Hadron 2011 June 16,

14 J PC =2 + γp π + π + π n D.P. Weygand Hadron 2011 June 16,

15 γp π + π + π n J PC =1 + D.P. Weygand Hadron 2011 June 16,

16 γp ηπ ++ γ π - a2,π1 γ η p Δ ++ π + γ p D.P. Weygand Hadron 2011 June 16,

17 γp ηπ ++ γ π - a2,π1 γ η π p Δ ++ π + γ p D.P. Weygand Hadron 2011 June 16,

18 Invariant Mass of pγ π η(γγ) ++ (pπ + ) Diane Schott Invariant Mass of p h_p_pip Entries Mean 1.44 RMS Invariant Mass of p + (GeV) heta_mm_pim Entries Mean RMS Invariant Mass - (GeV) D.P. Weygand Hadron 2011 June 16,

19 Exotic Baryons g6 c γp (K + n)k π+ D.P. Weygand Hadron 2011 June 16,

20 Exotic Baryons g6 c γp (K + n)k π+ D.P. Weygand Hadron 2011 June 16,

21 g12 Miles Price and Paul Stoler g6 c g12 D.P. Weygand Hadron 2011 June 16,

22 g12 Miles Price and Paul Stoler g6 c g12 D.P. Weygand Hadron 2011 June 16,

23 g12 Miles Price and Paul Stoler g6 c g12 D.P. Weygand Hadron 2011 June 16,

24 g7/g12 e + e - π 0 Dalitz Decay Mike Kunkel/ODU Moskov Amarian + - Invariant Mass e e! # of Entries / 3 MeV M(e - e!) [GeV] D.P. Weygand Hadron 2011 June 16,

25 g7/g12 e + e - # of Entries / 5 MeV # of Entries / 3 MeV π 0 Dalitz Decay Invariant + - Invariant mass Mass of e! e dilepton! pair PRELIMINARY UNCORRECTED M(e Mike Kunkel/ODU Moskov Amarian e - e!) )[GeV] D.P. Weygand Hadron 2011 June 16,

26 η Dalitz Decay WASA/Celcius Cleo D.P. Weygand Hadron 2011 June 16,

27 g12 η Dalitz Decay + - Invariant Mass e e! # of Entries / 5 MeV M(e - e!) [GeV] D.P. Weygand Hadron 2011 June 16,

28 g12 η Dalitz Decay # of Entries / 5 MeV + - Invariant Mass e e! # of Entries / 40 MeV Invariant mass of! diplepton pair M(e PRELIMINARY UNCORRECTED - e!) [GeV] + M(e - e ) [GeV] D.P. Weygand Hadron 2011 June 16,

29 η' Dalitz Decay g12 Cleo + - Invariant Mass e e! # of Entries / 8 MeV Dashed Lines are Monte-Carlo Prediction. Solid Line is measured result M(e + e -!)[GeV] D.P. Weygand Hadron 2011 June 16,

30 η' Dalitz Decay g12 Cleo + - Invariant Mass e e! # of Entries / 40 MeV Invariant mass of! diplepton pair PRELIMINARY UNCORRECTED M(e + e - ) [GeV] # of Entries / 8 MeV M(e + e -!)[GeV] Dashed Lines are Monte-Carlo Prediction. Solid Line is measured result. D.P. Weygand Hadron 2011 June 16,

31 X φη Mukesh Saini/FSU Paul Eugenio K+K- Mass φ(1020) f2 (1525) (4 I ϕ η D.P. Weygand Missing Mass/pϕ Hadron 2011 June 16,

32 D.P. Weygand Hadron 2011 June 16,

33 γp (φη)p t < 0.1 GeV 2 D.P. Weygand Hadron 2011 June 16,

34 f1(1285) I (4 f1(1285) a0(980) π ϕ π D.P. Weygand Hadron 2011 June 16,

35 N ωp CLAS g 11 E e = 4 GeV Mike Williams Curtis Meyer (CMU) N* (s-channel) + ω (t-channel) Text Furthermore, the ability of the PWA fit, which contains only the F15(1680) and D13(1700) s-channel amplitudes and the 0 t-channel amplitude, to reproduce both our dσ/d cos ϑ spin density matrix for s < 2 GeV is truly remarkable. It is also important to note that the large angle cross section for s < 1.85 GeV is virtually flat. This demonstrates the importance of the spindensity measurements. At higher energies, we have found fairly strong evidence for the presence of the **** G17(2190) resonance. The cross sections extracted for the J P = 7/2 partial wave are in excellent agreement with this hypothesis. s = 1.8 GeV s = 2.1 GeV D.P. Weygand Hadron 2011 June 16,

36 Carlo Salgado pγ pk + K π + π (π 0 ) W. Phelps/CNU and NSU φ K + K D.P. Weygand Hadron 2011 June 16,

37 MM/ϕ Mass(ηφ) Mass(ωp) D.P. Weygand Hadron 2011 June 16,

38 N pη φ φη φ(1680) φ 3 (1850) φ(2175) D.P. Weygand Hadron 2011 June 16,

39 Ξ* Spectroscopy Ξ Ground State Mass difference: 6.48 ± 0.24 MeV Only one measurement of Ξ 0 mass has more than 50 events SU(3) flavor symmetry requires one Ξ I=1/2 per octet and per decuplet: n(ξ*)=n(n*) +n(δ*) QM predicts 45 cascades with mass below 2.5 GeV (S.Capstick and N. Isgur PRD (1986)) Algebraic model predicts 33 states with mass below 2.5 GeV (A.R. Bijker, F.Iachello, and A. Leviatan Ann. Phys (2000) Suggests many states missing experimentally Of the 6 **** & *** PDG Ξ states, J P determined for only 3 Ξ Production Mechanisms not well understood D.P. Weygand Hadron 2011 June 16,

40 Jenkins et. al,phys.rev.lett. 51 (1983) BNL MPS D.P. Weygand Hadron 2011 June 16,

41 Jenkins et. al,phys.rev.lett. 51 (1983) BNL MPS D.P. Weygand Hadron 2011 June 16,

42 Jenkins et. al,phys.rev.lett. 51 (1983) BNL MPS D.P. Weygand Hadron 2011 June 16,

43 γp K + K + X Jenkins et. al,phys.rev.lett. 51 (1983) BNL MPS D.P. Weygand Hadron 2011 June 16,

44 γp K + K + X D.P. Weygand Hadron 2011 June 16,

45 γp K + K + X D.P. Weygand Hadron 2011 June 16,

46 γp K + K + X D.P. Weygand Hadron 2011 June 16,

47 Conclusions Previous CLAS result on exotic π 1 (1600)/a 2 (1320) in photoproduction confirmed with higher statistics Previous CLAS result on γp pentaquark not confirmed with higher statistics High luminosity allows exploitation of 'rare' topologies γp φπ 0 p, φηp, φωp No observation of any Ξ* states above 1530 MeV recoiling off of K + K + Lepton detection permits high statistic study of pseudoscalar Dalitz decay first observation of η' Dalitz decay; ρ-ω interference via e + e - channel D.P. Weygand Hadron 2011 June 16,