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Title: Quasi-free Cross Section Measurements at CLAS: γ D → p π - ( p ) , γ D → K * ( 892 ) 0 Λ ( p ) , γ D → K + Σ * ( 1385 ) - ( p )

Abstract

Preliminary measurements of the quasi-free differential cross sections of the gD -->pp-(p), gD --> K*(892)0L(p), and gD --> K+S*(1385)-(p) reactions are shown using data from the Jefferson Lab Hall B CLAS g13 experiment. No experimental cross section data have yet been published on gD --> K*(892)0L(p), and the only published cross section data on gD --> K+S*(1385)-(p) are at forward angles, where t-channel K+ and K*+ exchanges are predicted to dominate. These data can be used to contribute to the search for the "missing" N* resonances, some of which are predicted to have non-negligible couplings to the excited strangeness channels. These cross sections are shown to be sizable compared to the ground-state channels, indicating that it is important to include excited channels in coupled-channels analyses used to extract the N* resonances. In addition, the gD --> pp-(p) data provide a significant increase to the world statistics, and will be used to study rescattering effects within the deuteron.

Authors:
 [1]
  1. Carnegie Mellon U., JLAB
Publication Date:
Research Org.:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
OSTI Identifier:
1168666
Report Number(s):
JLAB-PHY-13-1840; DOE/OR/23177-3061
DOE Contract Number:
AC05-06OR23177
Resource Type:
Conference
Resource Relation:
Journal Name: Proceedings of Science; Journal Volume: HADRON13; Conference: Hadron 2013, 4-8 November 2013, Nara, Japan
Country of Publication:
United States
Language:
English

Citation Formats

Mattione, Paul. Quasi-free Cross Section Measurements at CLAS: γ D → p π - ( p ) , γ D → K * ( 892 ) 0 Λ ( p ) , γ D → K + Σ * ( 1385 ) - ( p ). United States: N. p., 2014. Web.
Mattione, Paul. Quasi-free Cross Section Measurements at CLAS: γ D → p π - ( p ) , γ D → K * ( 892 ) 0 Λ ( p ) , γ D → K + Σ * ( 1385 ) - ( p ). United States.
Mattione, Paul. Mon . "Quasi-free Cross Section Measurements at CLAS: γ D → p π - ( p ) , γ D → K * ( 892 ) 0 Λ ( p ) , γ D → K + Σ * ( 1385 ) - ( p )". United States. doi:. https://www.osti.gov/servlets/purl/1168666.
@article{osti_1168666,
title = {Quasi-free Cross Section Measurements at CLAS: γ D → p π - ( p ) , γ D → K * ( 892 ) 0 Λ ( p ) , γ D → K + Σ * ( 1385 ) - ( p )},
author = {Mattione, Paul},
abstractNote = {Preliminary measurements of the quasi-free differential cross sections of the gD -->pp-(p), gD --> K*(892)0L(p), and gD --> K+S*(1385)-(p) reactions are shown using data from the Jefferson Lab Hall B CLAS g13 experiment. No experimental cross section data have yet been published on gD --> K*(892)0L(p), and the only published cross section data on gD --> K+S*(1385)-(p) are at forward angles, where t-channel K+ and K*+ exchanges are predicted to dominate. These data can be used to contribute to the search for the "missing" N* resonances, some of which are predicted to have non-negligible couplings to the excited strangeness channels. These cross sections are shown to be sizable compared to the ground-state channels, indicating that it is important to include excited channels in coupled-channels analyses used to extract the N* resonances. In addition, the gD --> pp-(p) data provide a significant increase to the world statistics, and will be used to study rescattering effects within the deuteron.},
doi = {},
journal = {Proceedings of Science},
number = ,
volume = HADRON13,
place = {United States},
year = {Mon Sep 01 00:00:00 EDT 2014},
month = {Mon Sep 01 00:00:00 EDT 2014}
}

Conference:
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  • We analyze recent K + meson photoproduction data from the CLAS collaboration for the reactions γp → K +Λ and γp → K +Σ 0 , fitting measured forward-angle differential cross sections to the form AeBt. We develop a quantitative scheme for determining the kinematic region where the fit is to be done, and, from the extracted t-slope B, determine whether single-Reggeon exchange can explain the production mechanism. We find that, in the region 5 < s < 8.1 GeV2 , production of the K +Λ channel can be explained by single K + Reggeon exchange, but the K +Σmore » 0 production channel cannot. We verify these conclusions by fitting the data to a differential cross section produced by the interfering sum of two exponential amplitudes.« less
  • Preliminary measurements of the differential cross sections of the γn→Κ*(892)⁰Λ and γn→Κ⁺Σ*(1385)⁻ reactions are shown using data from the Jefferson Lab Hall B CLAS g13 experiment. No experimental cross section data have yet been published on the γn→Κ*(892)⁰Λ reaction, and the only published cross section data on the γn→Κ⁺Σ*(1385)⁻ reaction are at forward angles, where t-channel K⁺ and K* + exchanges are predicted to dominate. These data can be used to contribute to the search for the 'missing' N* resonances, some of which are predicted to have non-negligible couplings to the excited strangeness channels.
  • Thesis. Submitted to Chicago Univ., Ill. Dept. of Physics. The differential cross section in the reaction π -p→ K°Λ°, π -p→ K°Σ° was measured at incident beam momenta of 3, 4 and 6 GeV/c and at momentum transfers to t approximates - 2.0. The polarization of Λ° was also measured at 5 GeV/c using the parity violating decay Λ° → pπ -. Wire spark chambers with magnetostrictive readout, scintillators, and Cerenkov counters were used and most of the calculations were performed on-line with an EMR6050 computer. Due to the experimental method the results have much smaller error than previous bubblemore » chamber measurements.« less
  • Thirteen N * states have been well-established according to the Particle Data Group, but some relativized quark models predict that many more N * resonances exist. Diquark models predict that the N * spectrum is limited by a correlated quark-pair in the nucleon, but there is strong evidence for the existence of the N 3/2 +(1900) ** resonance, which is absent in diquark models. Measuring the spectrum of N * states will provide valuable information on the relevant degrees of freedom within the nucleons. Most of the experimental searches for the N * states have been conducted in the πmore » N channel. Some models of baryon decays predict that most of the unobserved N * states couple somewhat weakly to the π N channel, and that some couple non-negligibly to the KY, K *Y, and KY * channels. Measurements of the cross sections and polarization observables of strangeness photoproduction reactions can provide additional information on the spectrum of N * states. These measurements can be used in coupled-channel partial-wave analyses that can provide simultaneous constraints on the N * resonance parameters from several channels. These analyses can also take into account hadronic rescattering, which is predicted to have a large effect on the measured cross sections. However, to determine the isospin decomposition of the photo-transition amplitudes to these channels, photoproduction measurements are necessary on both the proton and the neutron. Measurements of the differential cross sections of the γn\rightarrow K *(892) 0Λ and γn→ K +Σ *(1385) - reactions have been performed using data from the Jefferson Lab Hall B CLAS g13 experiment. No experimental cross section data have yet been published on the γ n\rightarrow K *(892) 0Λ reaction, and the only published cross section data on the γn→ K +Σ *(1385) - reaction are limited to forward angles, where t-channel K + and K^ *+ exchanges are predicted to dominate. These cross sections are compared against theoretical models to study the channel interactions that give rise to their distributions. These reactions also have the same final state particles (K +π --), so studies of their potential interference were performed as well. A measurement of the γn→ pπ - cross section was also performed, and the agreement with published results within the uncertainties validated the integrity of the data and procedures used in this analysis.« less