[Clas_hadron] Abstract for DNP 2010

[Michael Evan McCracken]

Dear Spectroscopists,
  I'd like to give a contributing talk at DNP this coming October in 
which I'll promote our on-going mass-independent PWA of the K+ Lambda 
photoproduction reaction.  I plan to present methods and techniques for 
the analysis and perhaps show some preliminary results.  I'll remind you 
that Mike Williams had success in applying very similar techniques to 
the p omega channel (PRC 80, 065209, (2009)).  This will mostly be an 
overview talk of our procedure to show the experimental and theory 
communities that this alternative to the mass-dependent PWA is robust 
and is being investigated.
  I've placed a copy of my abstract at:
     
/u/site/www/html/Hall-B/secure/hadron/abstracts/2010/DNP2010_MMcCracken.pdf
  I've also included the TeX of the abstract below.
  I welcome any comments.  Please send them to clas_hadron at jlab.org.
Many thanks.
-Mike McCracken

-- 
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Michael Evan McCracken, Ph.D.
Assistant Professor of Physics
Washington & Jefferson College
60 South Lincoln Street
Washington, PA 15301
(724)503.1001 x6148
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\large{Mass-independent Partial-wave Analysis of $K^{+} \Lambda$ Photoproduction: Data, Scope, and Techniques}
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\underline{Michael McCracken for the CLAS Collaboration}

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Washington \& Jefferson College\\
Washington, PA 15301, USA\\
e-mail: mmccracken at washjeff.edu\\

Couplings of $N^{*}$ states to two-body final states have been predicted using relativized quark-model calculations.  
The photoproduced $K^{+}\Lambda$ system presents a unique opportunity to study the excited nucleon spectrum for several reasons.
The $K^{+}\Lambda$ final state couples only to iso-spin-$\frac{1}{2}$ intermediate states, allowing for a simpler interpretation of resonant contributions.
Furthermore, the self-analyzing nature of the $\Lambda\rightarrow p \pi^{-}$ decay allows for measurement of the $\Lambda$ polarization.
Several recent experiments have exploited this feature to produce measurements of both single- and double-polarization observables for the reaction.  
As such, this $K^{+}\Lambda$ photoproduction is a strong candidate for a so-called \textit{complete} set of observables from which the transition amplitudes can be determined.

Recent large-statistics measurements of the differential cross section, $\Lambda$ recoil polarization, and beam-$\Lambda$ polarization transfer made by the CLAS Collaboration, warrant new partial-wave techniques.
We present our method for and preliminary results of the mass-independent partial-wave analysis of the $\gamma p \rightarrow K^{+}\Lambda$ reaction.
Methods for constraining fits to observables from the GRAAL and LEPS experiments, including beam and target asymmetries and polarization transfer observables, are described.
We discuss the differences in formalism, methodology, and interpretation between this mass-independent and previous mass-dependent analyses, and discuss techniques for applying the mass-independent technique to resolve ambiguities in previous analyses of the reaction.