Constraints on background contributions fromK+Λelectroproduction

Abstract

Results for response functions for kaon electroproduction on the proton are presented. A treelevel hadrodynamical model is adopted and it is shown that some of the electroproduction response functions are particularly powerful with the eye on gaining control over the parameterization of the background diagrams. The existing data set for the p(e, e ′ K + )Λ reaction appears to rule out the use of a g K + Λp coupling constant beyond the boundaries of softly broken SU(3) flavor symmetry. Also the use of soft hadronic form factors, which has been proposed as a valid alternative for a hadrodynamical description of the p(γ, K + )Λ data in the resonance region, seems to be disfavored by the magnitude of the measured p(e, e ′ K + )Λ cross sections.

Separated structure functions for the exclusive electroproduction ofK+ΛandK+Σ0Ambrozewicz1, Carman2, Feuerbach3 et al. 2007Phys. Rev. C592310View full textAdd to dashboardCite

“…The coupling constants for each of the included resonances are extracted from global fits of the model calculations to the existing data base. It is common practice to use phenomenological form factors to account for the extension of the pointlike interactions at the hadronic vertices [25]. Different models typically have different prescriptions for restoring gauge invariance.…”

“…The first is the model of Mart and Bennhold [26] (referred to here as MB), and the second is model B of Janssen et al [25] (referred to here as JB). In these models, the coupling strengths were determined mainly by fits to existing γp → K + Y data (with some older electroproduction data included in some cases) by adding the nonresonant Born terms with a number of resonance terms in the s, t, and u reaction channels, leaving the coupling constants as free parameters.…”

Electromagnetic production of kaons from protons, and baryon electromagnetic form factors

“…Much of the theoretical work, especially the earlier work, employed effective Lagrangian models [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], but several recent studies are based on coupled-channel approaches or chiral unitary frameworks [19][20][21][22][23]. There is currently a wealth of photoproduction data from several groups, including SAPHIR [24], LEPS [25], GRAAL [26,27], and CLAS [28][29][30][31].…”

“…The earliest theoretical studies of electroproduction date from the mid 1970s, and were based on a simple Regge model [37]. More recent studies generally employ an effective Lagrangian model [2,4,7,9,10,14,38,39] and often treat both the electroproduction and photoproduction reactions together. There also exist updated Regge analyses of electroproduction [40] and studies based on chiral frameworks [23,41].…”

Separated structure functions for exclusiveK+ΛandK+Σ0electroproduction at 5.5 GeV measured with CLAS

“…• The structure functions are particularly powerful to gain control over the parameterization of the background diagrams [29].…”