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K(892) *0 Λ and K + Σ(1385) - Photoproduction on the Deuteron. Paul Mattione , Rice University for the CLAS Collaboration. Advisors: Dan Carman, Jefferson Lab Paul Padley , Rice University. APS 2010 April Meeting. February 15, 2010. Overview. Missing N* resonances
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K(892)*0Λ and K+Σ(1385) -Photoproduction on the Deuteron Paul Mattione, Rice University for the CLAS Collaboration Advisors: Dan Carman, Jefferson Lab Paul Padley, Rice University APS 2010 April Meeting February 15, 2010
Overview • Missing N* resonances • Predicted by quark models • High mass N* states: wide, overlapping • Most current information comes from πN analyses • Coupling to Y and Y* decay channels (e.g. N(2190)G17****)ł • γD -> K(892)*0Λ(p) and γD -> K+Σ(1385)-(p) • Same final state (p, K+, π-, π-) • Intend to measure cross sections for both • Jefferson Lab CLAS g13a data (October 2006 – June 2007) • Ee 2.0, 2.65 GeV, circularly polarized photons • Event selection • K(892)*0Λ, K+Σ(1385)- interference and yields • Acceptance correction in progress łCapstick, Roberts; Phys Rev D, 58 074011 (1998) APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
K(892)*0Λ Predictions • Model based on effective Lagrangians • Cross-sections predominantly t-channel process (red lines) • However, in the s-channel calculations only the Born term is included • No resonant s-channel terms included because not enough information yet on couplings * Oh, Kim; arxiv:0602112v4 (2006) APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
K+Σ(1385)- Predictions, LEPS Data • Model based on effective Lagrangians • Theory model by Oh, Ko, and Nakayama (Phys Rev C, 77 045204 (2008)) • Data by Hicks, et al. (LEPS); arxiv:0812.0771v1 (2008) • Haiyun Lu (eg3) – high energy, g13 – near-threshold energy APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
Jefferson Lab CEBAF & CLAS APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
Event Selection • Same final state particles (p, K+, π-, π-) • Λ, (p) Gaussians cut at 3σ APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
Interference in Eγ Bins • 200 MeVEγ Bins, 1.5 – 2.5 GeV • Negligible interference at Eγ < 1.9 GeV • (K(892)*0Λ threshold ~1.65 GeV, minimum momentum cuts) APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
Interference Cut • For Eγ > 1.9 GeV: Fit K(892)*0 and Σ(1385)- to Breit-Wigners, interference cut at 80% APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
Signals • Σ(1385)- • 45707 Signal Events • 16.3 Signal/Back Ratio • PDG (MeV) 1387, 39.4 • K(892)*0 • Eγ > 1.9 GeV • 6985 Signal Events • 2.15 Signal/Back Ratio • PDG (MeV) 896, 50.3 APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
K(892)*0Λ Yield • 200 MeV bins, background not subtracted • Statistical errors only APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
K+Σ(1385)- Yield • 200 MeV bins, background not subtracted • Statistical errors only APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010
Major Ongoing/Future Work • Measuring γD -> pπ-(p) cross section, compare to SAID • Test of g13a data • Understand detector inefficiencies • γD -> K(892)*0Λ(p) and γD -> K+Σ(1385)-(p) cross sections • Finalize acceptance correction • Sideband subtraction underneath signal peaks • Systematic error studies APS 2010 April Meeting Paul Mattione, Rice University February 15, 2010