Richard Lindgren

Professor Lindgren conducts experiments that provide critical test of QCD and quark models in the perturbative and non-perturbative regime of QCD. The experiments utilize electromagnetic probes such as electrons and are conducted at the Thomas Jefferson National Accelerator Facility (JLab). Lindgren was PI of the MRI/NSF Grant that provided funds to install and upgrade the large acceptance BigBite spectrometer with new multiwire drift chambers in Hall A at JLab. The funds also provided for a new scattering chamber and target cells. The large acceptance (90 msr) spectrometer and high counting rate and low mass multiwire chambers have provided for a new generation of fundamental and novel experiments at JLab. Professor Lindgren was the co-spokesperson and contact person of one of the first approved experiments, E04-007, a high precision measurement of the reaction H(e,e´p)π⁰ near threshold to test Chiral Dynamics. This will provide a critical test of Chiral Perturbation Theory, an effective field theory in the low energy non-perturbative regime of QCD. Two UVa graduate students have been analyzing the H(e,e´p)π⁰ data and one Ph.D. thesis has already been completed on the analysis of the beam asymmetry data near threshold. The analysis of the absolute cross section data near threshold is expected to be completed soon. New pion electroproduction experiments are presently being considered for the new 12 GeV JLab upgrade. Specific proposals will depend on the outcome of the results from the analysis of the current data.