Part of the XENON100 experiment (Courtesy: XENON100 collaboration)
By Hamish Johnston
Is the XENON100 collaboration in the dark about dark matter, or will its critics see the light? The latest installment of this debate has appeared on the arXiv preprint server.
On 6 May Jon Cartwright reported on a furore that has broken out in the dark-matter detection community.
Earlier that week the XENON100 collaboration posted a preprint with an analysis of the first experimental results from its dark-matter detector. It didn’t see any of the dark stuff, which means that the positive sightings reported by two other experiments (DAMA and CoGeNT) could be false.
But then two US-based physicists – Juan Collar and Dan McKinsey — posted a preprint that took XENON100 physicists to task on their analysis of the data. In particular, Collar and McKinsey believe that the XENON100 team is overconfident about how it extrapolated the known response of the detector to high-energy particles to lower energies – where the response is unknown.
This low-energy response is crucial because that is where XENON100, DAMA and CoGeNT have all looked for dark matter.
Now, XENON100 has responded with yet another preprint defending its analysis and claiming that it has “properly taken into account the uncertainty” in the low-energy response.
I can’t wait for the next preprint in this dark-matter “he said, she said”!