CLAS Hadron Spectroscopy Working Group Meeting Report CLAS

CLAS Hadron Spectroscopy Working Group Meeting Report, CLAS 12 2 nd European Workshop/ CLAS Collaboration Meeting, March 2011

Analyses Under Working-group Review - 1 Measurement of the Lineshape, Differential Photoproduction Cross Section, Spin and Parity of the Lambda(1405) Using CLAS at Jefferson Lab Contact persons: Reinhard Schumacher, Kei Moriya Analysis Review Committee: Paul Eugenio (chair), Raffaella De Vita, Mac Mestayer Committee formed November 8, 2010 First round comments; awaiting author response Photoproduction of the phi(1020) with linearly polarized photons from the proton Contact persons: Julian Salamanca and Phil Cole Analysis Review Committee: Bryan Mc. Kinnon (chair), Pawel Nadel-Turonski, Mike Wood Committee formed June 10, 2010 Second round comments; awaiting author response Differential cross sections and SDME for phi(1020) photoproduction from g 11 Contact persons (CMU): Biplab Dey and Curtis Meyer Contact persons (ODU): Heghine Seradaryan and Moskov Amarian Analysis Review Committee: Lei Guo (chair), Raffaellla De. Vita, Michael Dugger, Valery Kubarovsky Committee formed July 20, 2010 Awaiting confirmation of consistent results

Analyses Under Working-group Review – 2 Review #4709539: "Photo-production of Σ∗+(1385) with CLAS" (1 st round ended on March 4, 2011) Initiated by: David Ireland Review type: Analysis Status: Contact author: Gagik Gavalian Experiment/Working group: g 11/HS Committee: Kenneth Hicks (Chair), Ralf Gothe , Eugene Pasyuk Review deadline: March 4, 2011 Pending Analyses Reviews Photoproduction of Lambda 1520 Hyperon off Protons and Neutrons in Deuterium" with eg 3 data. Contact author: Zhiwen Zhao Awaiting formation of committee

Ad-Hoc Reviews Review #8061056: "Upper limits for photoproduction cross section for the Φ --(1860) pentaquark state" (1 st round ended on January 31, 2011) Initiated by: Hovanes Egiyan Review type: Ad-hoc Status: 1 st round ended Contact author: Hovanes Egiyan Experiment/Working group: eg 3/HS Committee: Reinhard Schumacher (Chair), Angela Biselli , Gerard Gilfoyle Review deadline: January 31, 2011

PAC Proposals Meson Spectroscopy with low Q 2 electron scattering in CLAS 12 Contact persons: Marco Battaglieri and Raffaella De Vita Analysis Review Committee: Volker Crede (chair), Chaden Djalili, Hovanes Egiyan PAC result: A-

Collaboration-wide review Review #5573944: "Electromagnetic decay of the Sigma*0 to Lambda gamma" (Ended on March 1, 2011) Initiated by: Marco Ripani Review type: Collaboration-wide Status: Ended Contact author: Kenneth Hicks Experiment/Working group: g 11/HS Review deadline: March 1, 2011

Agenda 14: 15 Opening comments - Dave Ireland 14: 20 Measuring the G polarisation observable for KΛ photoproduction from g 9 a Stuart Fegan 14: 45 Search for Missing Resonances in γp -> K Λ using Circularly Polarized Photons on a Polarized Target - Liam Casey 15: 10 Electroproduction of hybrid 1 -+ mesons - Samuel Wallon 15: 35 OZI and G-parity violating decays of η' and φ mesons - Moskov Amaryan

Double Polarization Observables in gp→K+L using Circularly Polarized Photons incident on FROST (g 9 a) Liam Casey Catholic University of America CLAS 12 European Meeting Hadron Spectroscopy Group

+ Missing Mass M(X) (gp→K X) Kaon vertex distribution determines the target of event origin. The missing mass off the Kaon can be used to find Λ and Σ signals in both targets.

Consistency – Recoil Polarization 1. 4 Ge. V 1. 5 Ge. V The recoil polarization P shows good agreement with g 11 data across most of the energy range. These are typical bins. Here I calculate P in an integrated manner taking the asymmetry in protons falling above and below the reaction plane. Technically, recoil asymmetry from carbon should be subtracted.

G 1 C to G 1 C Comparison 1. 4 Ge. V Values of g 1 c analysis are rotated to primed coordinate system according to the rubric of Sandorfi. 1. 5 Ge. V A. M. Sandorfi et al. , ar. Xiv: 1010. 455 v 1 [nucl-th] 21 Oct 2010

Helicity Asymmetry E E plotted for the missing D 13 relevant 1. 5 Ge. V photon energy bin Dilution calculated by angular bin, PT and Pγ for each kinematic bin. Solid blue line shows kaon-MAID Model of T. Mart. Dashed orange line is the model of B. Saghai, which includes hyperonic resonances in place of D 13 and the dot-dash magenta line is the SAID based PWA of GWU.

Polarization Transfer Lx' and Lz' 1. 5 Ge. V Lx‘ and Lz’ are calculated in the same manner as the beam-recoil polarization transfer with the target polarization magnitude and direction replacing the beam circular polarization and helicity.

Rare Decays of Light Mesons in CLAS. Preliminary Results. M. Amaryan, G. Gavalian, C. Nepali Old Dominion University Norfolk, VA CLAS Collaboration Meeting Paris, March 10, 2011

Missing Mass π0 K 0 η ω We use g 11 Data: 3 charged track events identified as a proton and two oppositely charged pions

First Observation of G-Parity Violating Decay of φ Meson η‘ f 1(1285) Φ Theory prediction: Br( ) ~3 x 10 -7 PDG Exp. limit Br<1. 8 x 10 -5 M=1. 021 Ge. V σ = 0. 005 Ge. V (I. J. M. Phys. A, Vol. 7, No. 20(1992), 482

OZI Rule Violating Decay of ϕ meson in photoproduction ω η‘ η Very Different from e+eannihilation! η‘ ϕ ϕ

First Observation of rare EM decay of η meson η’ ω (PDG) η (Not seen before, an upper limit is quoted in PDG. )

Summary Table reaction decay γp->pπ+π-η ϕ(π+π-η) (not seen before) γp->pπ+π-π0 ϕ(π+π-π0) (not in γp) γp->pπ+π-γ ω(π+π-γ) (not seen before) ϕ(π+π-γ) (not seen before) <3. 6 x 10 -3 η(π+π-π0γ) (not seen before) ω(ηγ) (not in γp) <5 x 10 -4 γp->pπ+π-π0γ OZI violated G-parity violated X X Br (PDG) <1. 8 x 10 -5 15. 3% <4. 1 x 10 -5 4. 6 x 10 -4 2. 75%