First Dark Matter Results from the XENONnT Experiment
The XENON consortium is made up of 170 scientists from 28 research groups in the USA, Germany, Portugal, Switzerland, France, the Netherlands, Sweden, Japan, Israel and Abu Dhabi.
With the participation of four scientists from LIBPhys of the Faculty of Sciences and Technology of the University of Coimbra (FCTUC); the XENON international collaboration has announced the first results obtained by XENONnT, a system with an unprecedented sensitivity to detect dark matter
Two years ago, the XENON collaboration announced the observation of an excess of electronic recoil events in the XENON1T experiment. The result triggered a lot of interest and many publications since this could be interpreted as a signal of new physics beyond known phenomena.
Today the XENON collaboration has released the first results from its new and more sensitive experiment, XENONnT, with one-fifth of the electronic recoil background of its predecessor, XENON1T. The results published today (https://arxiv.org/) are the result of 97 days of measurements carried out between July and November 2021. The absence of an excess in the new data indicates that the origin of the XENON1T signal was trace amounts of tritium in the liquid xenon, one of the hypotheses considered at the time. In consequence, this leads now to very strong limits on new physics scenarios originally invoked to explain an excess.
With this new result, obtained through a blind analysis, XENONnT makes its debut, with an initial exposure slightly larger than 1 tonne x year. The existing data are being further analyzed to search for weakly interacting massive particles (WIMPs), one of the most promising candidates of Dark Matter in the Universe. XENONnT is meanwhile collecting more data, aiming for even better sensitivity as part of its science program for the next years.
The XENON consortium consists of 170 scientists from 28 research groups from the USA, Germany, Portugal, Switzerland, France, the Netherlands, Sweden, Japan, Israel and Abu Dhabi. Portugal has been a partner in this collaboration since its inception in 2005, through the LIBPhys team at the University of Coimbra, which has been funded by the Portuguese Foundation for Science and Technology (FCT) since its inception and until 2021.