Differential Photoproduction Cross Sections of the $\Sigma^0(1385)$, $\Lambda(1405)$, and $\Lambda(1520)$

  • CLAS Collaboration (Contributor)



The CLAS collaboration at Jefferson Lab measured the reactions gamma + p-->K+ + Sigma + pi and gamma + p-->K+ + Lambda + pi0 over a broad range of photon energies and kaon production angles. The results summarized below are from the Ph.D. work of Kei Moriya, in collaboration with Professor Reinhard A. Schumacher, at Carnegie Mellon University in Pittsburgh, Pennsylvania. The thesis work was completed in October 2010. The thesis was entitled -Measurement of the Lineshape, Differential Photoproduction Cross Section, Spin and Parity of the Lambda(1405) Using CLAS at Jefferson Lab. The main body of the thesis describes the results given below, however, the numbers given here reflect an extra round of detailed checks and systematic studies summarized in a CLAS Analysis Note entitled - Addendum on Lambda(1405) Studies Using G11A, dated October 2, 2011. The thesis is available at www.jlab.org/Hall-B/general/clas_thesis.html. The analysis note is also somewhere on the CLAS web site. All known corrections were applied to the yield extraction, normalization, and acceptance calculations in these data. The given error bars are essentially statistical but include the fit uncertainties assiciated with background subtraction. The column headings below should be self-explanatory. For each of nine bins in W that are each 100 MeV wide (2.0, 2.1, ... , 2.8 GeV), the total cross sections are tabulated using a sum over the measured range of kaon center-of-mass angles in CLAS, followed by an extrapolation to the full angular range. The results for each of the three hyperons is given, tabulated with the laboratory photon energy corresponding to the center of the W bin. The differential cross sections are given in the same W bins. However, in this case the first W bin for the L(1520) is only 30 MeV wide and centered at 2.035 GeV, rather than 100 MeV wide, since the wider bin size staddles the threshold. The first bin has an estimated normalization systematic of 36% on top of the 11.6% for the other bins. The overall systematic uncertainty in these results was estimated to be 11.6%. For details, consult the resources cited above. The tables below should be identical in content to the Appendix in the publication.
Date made availableJan 1 2013

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