Search

An experimental study of the 16O(e,e′K+)Λ16N [superscript 16 O (e, e prime K superscript +) superscript 16 subscript lambda N] reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e′K+)Λ,Σ0 [p (e, e prime K superscript +) lambda, sigma superscript 0] exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76±0.16 MeV was obtained for Λ16N [superscript 16 subscript lambda N] with better precision than previous measurements on the mirror hypernucleus Λ16O [superscript 16 subscript lambda O]. Precise energies have been determined for peaks arising from a Λ [lambda]in s and p orbits coupled to the p1/2 [p subscript 1/2] and p3/2 [p subscript 3/2] hole states of the 15N [superscript 15 N] core nucleus, United States. Dept. of Energy (Contract No. DE-AC05-84ER40150), Czech Science Foundation (Grant no. 202/08/ 0984), United States. Dept. of Energy (Contract No. DE-AC02-06CH11357), United States. Dept. of Energy (Contract No. DE-FG02-99ER41110), United States. Dept. of Energy (Contract No. DE-AC02-98-CH10886), National Science Foundation (U.S.)

An experimental study of the 16O(e,e′K+)Λ16N [superscript 16 O (e, e prime K superscript +) superscript 16 subscript lambda N] reaction has been performed at Jefferson Lab. A thin film of falling water was used as a target. This permitted a simultaneous measurement of the p(e,e′K+)Λ,Σ0 [p (e, e prime K superscript +) lambda, sigma superscript 0] exclusive reactions and a precise calibration of the energy scale. A ground-state binding energy of 13.76±0.16 MeV was obtained for Λ16N [superscript 16 subscript lambda N] with better precision than previous measurements on the mirror hypernucleus Λ16O [superscript 16 subscript lambda O]. Precise energies have been determined for peaks arising from a Λ [lambda]in s and p orbits coupled to the p1/2 [p subscript 1/2] and p3/2 [p subscript 3/2] hole states of the 15N [superscript 15 N] core nucleus, United States. Dept. of Energy (Contract No. DE-AC05-84ER40150), Czech Science Foundation (Grant no. 202/08/ 0984), United States. Dept. of Energy (Contract No. DE-AC02-06CH11357), United States. Dept. of Energy (Contract No. DE-FG02-99ER41110), United States. Dept. of Energy (Contract No. DE-AC02-98-CH10886), National Science Foundation (U.S.)

We present measurements of the ep → epπ0 [ep pi superscript 0] cross section extracted at two values of four-momentum transfer Q2 = 1.9 GeV2 [Q superscript 2 = 1.9 GeV superscript 2] and Q2 = 2.3 GeV2 [Q superscript 2 = 2.3 GeV superscript 2] at Jefferson Lab Hall A. The kinematic range allows one to study the evolution of the extracted cross section as a function of Q2 [Q superscript 2] and W. Results are confronted with Regge-inspired calculations and GPD predictions. An intepretation of our data within the framework of semi-inclusive deep inelastic scattering is also discussed., United States. Dept. of Energy. (Contract no. DOE-AC05-06OR23177), National Science Foundation (U.S.)

The kaon electroproduction reaction 1H(e,e′K+)Lambda was studied as a function of the virtual-photon four-momentum, Q[superscript 2], total energy, W, and momentum transfer, t, for different values of the virtual-photon polarization parameter. Data were taken at electron beam energies ranging from 3.40 to 5.75 GeV. The center of mass cross section was determined for twenty-one kinematics corresponding to Q[superscript 2] of 1.90 and 2.35 GeV[superscript 2], and the longitudinal, sigmaL, and transverse, sigmaT, cross sections were separated using the Rosenbluth technique at fixed W and t. The separated cross sections reveal a flat energy dependence at forward kaon angles not satisfactorily described by existing electroproduction models. Influence of the kaon pole on the cross sections was investigated by adopting an off-shell form factor in the Regge model, which better describes the observed energy dependence of sigmaT and sigmaL., United States. Dept. of Energy (Contract DE-AC05-84ER40150), Istituto Nazionale di Fisica Nucleare of Italy, GA of the Czech Republic (202/08/0984), United States. Dept of Energy (DE-AC02-06CH11357), United States. Dept of Energy (DE-FG02-99ER41065), United States. Dept. of Energy (DE-AC02-98-CH10886), Harvard University. Dept. of Physics. Jefferson Laboratory