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Possible Observation of Photon Speed Energy Dependence

V. Gharibyan
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Abstract

Current constraints on photon velocity variability are summarized and displayed in terms of an energy dependent vacuum refraction index. It is shown that the energy-momentum balance of high energy Compton scattering is very sensitive to the outgoing photon speed. A missing energy observation in HERA Compton polarimeter data indicates that photons with 12.7 GeV energy are moving faster than light by 5.1(1.4)mm/s. An asymmetry spectrum measured by the SLC longitudinal polarimeter implies however an effect which is 42 times smaller, although the interpretation of the data is less clear here.

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V. Gharibyan. 2005-03-23. Possible Observation of Photon Speed Energy Dependence. https://doi.org/10.1016/j.physletb.2005.02.053

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