August 21, 2015 – New results of international collaboration have emerged for the XENON100 experiment, according to the laboratories of the Gran Sasso National Institute of Nuclear Physics (INFN), questioning for the first time a variety of models so far accredited as possible explanations of dark matter. Among the models excluded from XENON100, there is also those assumed to explain the detected signal (for the first time in 1998) and then confirmed in the following years at the laboratories at Gran Sasso with the Dama / Libra experiment, and interpreted as a signal for dark matter particles. The study and the results obtained with XENON100 are being published in the journal Science and Physical Review Letters. “We continue hunting in the elusive dark matter world with this tool that allows the exploration of previously inaccessible regions. The Laboratories of the Gran Sasso INFN have confirmed their position as a privileged place for this kind of research,” is the comment of Fernando Ferroni, President of the Institute. The missing information to confirm the current image of the Cosmos, in which known matter is only a small part, will come with the direct detection of particles which are believed to be composed of dark matter. This research is made possible by the fact that particles of dark matter, abundant in our galaxy, can occasionally affect the atoms of material detectors and deposit some of their energy. However, the signals of dark matter are very difficult to detect, because weak and elusive and can easily be confused with similar signals but of different origin. The ability of XENON100 to minimize noise due to environmental radioactivity and other phenomena, lets researchers view each event, thus extending the search for dark matter in areas of energy and forms of interaction inaccessible until yesterday. Just the ability to embrace a multitude of features makes XENON100 a great tool, because no one knows what dark matter is, or how it interacts with ordinary matter. It is thus essential to assess most of the admissible hypotheses before moving forward. To date, the XENON100 experiment found no dark matter particles, but the characteristics demonstrated by the detector are very promising. The high sensitivity shown in the experimental results will allow the international research group to extend the search for dark matter to other forms until today excluded. “From the analysis of data with the XENON100, we know even more about what dark matter is not, which is very important information in the field of particle physics,” says Elena Aprile, of Columbia University, founder and head of the international cooperation that gave birth to the experiment. “We excluded models in which the interactions between dark and ordinary matter were stronger, and with the Xenon1T detector we can test models in which interactions are weaker. We can catch even the faintest hint of dark matter. If this is the place to look for the signature of dark matter, we should be able to see it.” (Red)