Let’s be open

Published in Physics World, 1 Feb 2015

Any great research finding in physics is sure to get people talking. Such was the case last January when physicists operating the CoGeNT detector at the Soudan Underground Laboratory in Minnesota, US, reported an intriguing rise in electronic blips at ener- gies of less than one kilo-electronvolt (keV). This is the sort of energy at which a particle of dark matter – that elusive, invisible substance thought to make up more than four-fifth’s of the universe’s matter – is expected to recoil off an atomic nucleus.

One person intrigued by the CoGeNT findings was Celine Boehm, a particle theorist at Durham University in the UK. She is not part of the collabo- ration and in normal circumstances would have had to take CoGeNT’s findings on trust. Fortunately for Boehm, the CoGeNT group had made public its full dataset, with all the electronic readings taken from a 0.5kg crystal of germanium over more than three years being available in an easily digestible format. Checking over the CoGeNT group’s analysis, and particularly its estimation of the fraction of signals that should be interpreted as background, Boehm and her colleagues concluded that there was not any significant rise in signal below 1 keV, after all. […]

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