Nikhef: new XENON100 analysis refutes a long-standing claim of dark matter detection

AMSTERDAM, 21-8-2015 — /EuropaWire/ — A new XENON100 analysis, published in Science this week, refutes a long-standing claim of dark matter detection. Dark matter is an abundant but unseen matter in the universe considered largely responsible for the gravitational force that keeps the Milky Way galaxy together. According to most current theoretical models, the hypothetical dark matter particles interact with atomic nuclei. However, such interactions have not been detected to date. The scientists of the XENON collaboration have developed novel analysis techniques to search for the first time in the data of the XENON100 detector for interactions of dark matter with electrons of the atomic shell. The analysis did not yield any signal above the very low background, further constraining the properties of dark matter.

This finding is of particular importance with respect to the results of the rival DAMA/LIBRA collaboration, which claims the detection of a dark matter signal with high significance. DAMA/LIBRA cannot distinguish between dark matter interactions with electrons or atomic nuclei. Searches by other experiments for interactions with atomic nuclei were not successful. Many theoretical models, which try to explain the observed discrepancy by assuming that dark matter particles interact only with electrons, are now excluded by the latest findings of the XENON collaboration. The new results should therefore revive the controversy about alternative explanations of the DAMA/LIBRA signal.

Together with 17 other institutes, Nikhef is part of the XENON collaboration. The consortium is currently completing the XENON1T experiment, an experiment 20 times more massive than XENON100, which will become the world’s most sensitive dark matter detector when it starts recording data later this year. To search further and fully characterize dark matter particles, the collaboration is designing the even larger XENONnT experiment to become operational in 2019. All XENON experiments operate at the Gran Sasso underground laboratory in Italy.

Link to XENON collaboration press release (to follow)
Link to Science publication

For more information:
Science Communications Department – mail – 020 592 5075
Programme leader XENON at Nikhef: Prof. dr. Patrick Decowski – mail
020 – 592 2145

SOURCE: Nikhef

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The measured rate of interactions in the DAMA/LIBRA (red) and XENON100 (blue) detectors. The observed modulation of the DAMA/LIBRA signal has been interpreted as due to dark matter interactions. XENON100 should have seen a very similar behavior if that interpretation were correct. However, the more than 100x lower interaction rate measured in XENON100 excludes this interpretation at more than 4.4 sigma. A new XENON100 analysis, published in Science this week, refutes a long-standing claim of dark matter detection. Dark matter is an abundant but unseen matter in the universe considered largely responsible for the gravitational force that keeps the Milky Way galaxy together. According to most current theoretical models, the hypothetical dark matter particles interact with atomic nuclei. However, such interactions have not been detected to date. The scientists of the XENON collaboration have developed novel analysis techniques to search for the first time in the data of the XENON100 detector

The measured rate of interactions in the DAMA/LIBRA (red) and XENON100 (blue) detectors. The observed modulation of the DAMA/LIBRA signal has been interpreted as due to dark matter interactions. XENON100 should have seen a very similar behavior if that interpretation were correct. However, the more than 100x lower interaction rate measured in XENON100 excludes this interpretation at more than 4.4 sigma.

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