The electromagnetic polarizabilities of the nucleon are fundamental nucleon-structure observables that characterize its response to external electromagnetic fields. The neutron polarizabilities can be accessed from Compton-scattering data on light nuclear targets. Recent measurements of the differential cross section for Compton scattering on the deuteron below the pion-production threshold have decreased the uncertainties in the neutron polarizabilities, yet the proton polarizabilities remain known substantially more accurately. As the sensitivity of the cross section to the polarizabilities increases with incident photon energy, measurements above the pion threshold may offer a way for an improved determination of the neutron polarizabilities. In this Rapid Communiciation, the first measurement of the cross section for coherent Compton scattering on the deuteron above the pion-production threshold is presented.
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The Lund Group acknowledges supportfrom the Swedish Research Council (Contracts No. 40324901and No. 80410001) and The Crafoord Foundation (GrantNo. 20060749). The Glasgow Group acknowledges supportfrom the Scottish Universities Physics Alliance (SUPA), theSUPA Prize Studentship, and STFC Grants No. 57071/1and No. 50727/1. Finally, support from NSF Grant No.PHY1309130, DOE Grants No. DE–SC0016581, No. DE–SC0016583, No. DE–FG02–06ER41422 and the NFS/IRESAward No. 0553467 is acknowledged by the authors inWashington, D.C. and Massachusetts Dartmouth.
Strandberg, B.; Annand, J. R. M.; Briscoe, W.; Brudvik, J.; Cividini, F.; Clark, L.; Downie, E. J.; England, K.; Feldman, G.; Fissum, K. G.; Glazier, D. I.; Hamilton, K.; Hansen, K.; Isaksson, L.; Al Jebali, R.; Kovash, Michael A.; Lipschutz, S.; Lundin, M.; Meshkian, M.; Middleton, D. G.; Myers, L. S.; O'Donnell, D.; O'Rielly, G.; Oussena, B.; Preston, M. F.; Schröder, B.; Seitz, B.; Strakovsky, I.; and Taragin, M., "Compton Scattering from the Deuteron Above Pion-Production Threshold" (2018). Physics and Astronomy Faculty Publications. 616.