The JLab Kaon Collaboration Homepage

This page provides information on Jefferson Lab Hall A experiments E98-108, "Electroproduction of Kaons up to Q² = 3 (GeV/c)² " and E94-107, "High Resolution 1p-Shell Hypernuclear Spectroscopy". The spokespersons on the two experiments are:

The Experiments

Experiment E98-108 measures kaon production cross sections, picking a specific reaction mechanism via a separation of response functions in the exclusive H(e,e'K⁺)Y reaction. This experiment will measure how kaons are electromagnetically produced -- meaning which production mechanisms contribute and to what extent.

Current knowledge is unsatisfactory with no systematic separation of either the competing production mechanisms or the resulting response functions. Multi-parameter models based on hadron dynamics (QHD) have attempted to explain the existing data, but a wider kinematical region has to be accessed in order to constrain the models and the g_KNY coupling constants. Three of the four unpolarized response functions will be separated over a range in Q², W, and t.

The longitudinal and transverse response functions will be separated by detecting kaons along the direction of the virtual photon, where only these terms contribute to the cross section. For each Q² kinematic the longitudinal and transverse responses will be separated at three different points in t. The separation of the longitudinal-transverse interference term will also be performed for selected kinematics, forming a sensitive test of the production model. The t-dependence of both the transverse response (at small |t|) and the full cross section will also be investigated, covering the transition from a semiphenomenological description in terms of mesons and baryons to a pQCD-based description in terms of quarks (or diquarks).

The Kinematics for January 2001 are Q²=2, 2.4 (GeV/c)², -0.45< t<-1.0 GeV², and W=1.85,1.9,1.95,2.13 GeV. The measured cross sections will be compared to both hadronic and subnucleonic reaction models. This will considerably extend the present electroproduction data. Incident beam energies of 3.395, 4.232, and 5.618 GeV will be utilized, along with the Hall A spectrometers, including both new diffusion aerogel counters.

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Run Coordinators:

The Proposals

Meetings, Collaboration, Contacts

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• Minutes for the meeting on November 30, 2000 are here.

Working Documents

• The final kinematics are here. This includes all data, 2001 and 2002.

• The online analysis clues from 2002 are here.

• The March 2002 kinematics are here.