- A JLab search for “heavy photons”, which are possible new massive vector bosons. We are involved in two JLab experiment which are searching for these postulated particles.
- A high precision measurement of the Bethe-Heitler asymmetry in the photon-induced production of electron-positron pairs of various nuclei (ϒ+Z → e++e-), this experiment is a stringent test of QED. The same experiment when performed on a proton target gives information of the interference of the first and second-order Born diagrams for electron scattering which cause a large difference is the extraction of the proton form factors when comparing Rosenbluth vs. polarization extractions), it is also related to the so called “contact term” in Deeply Virtual Compton Scattering (DVCS) which is as yet unmeasured. We expect to run a first stage of the experiment in the DUKE HIgS facility during 2014, with a second stage several months later. We are currently considering an extension to the experiment to take place in the Mainzer Microtron (MAMI) facility.
References:
- S. J. Brodsky and R. Lebed. Production of the Smallest QED Atom: True Muonium (μ+μ-). Phys. Rev. Lett. (2009) vol. 102 (21) pp. 213401
- H. Olsen, Creation of relativistic positronium. Physical Review D (1986)
- J.W. Motz et al. PAIR PRODUCTION BY PHOTONS. Reviews of Modern Physics (1969) vol. 41 (4P1) pp. 581-&
- S. J. Brodsky et al. Local two-photon couplings and the J=0 fixed pole in real and virtual Compton scattering. Phys Rev D (2009) vol. 79 (3) pp. 033012