XENON1T collaboration reported new results obtained in the most sensitive dark matter detector in the world. Scientists have recorded abnormally a lot of events that can be the evidence of the existence of new particles, solar axions, and new properties of neutrinos. Preprint posted on the website of Purdue University.
Dark matter constitutes approximately a quarter of the mass of the Universe. For many years scientists around the world trying to prove its existence experimentally, mainly because of the existence of dark matter indicate indirect gravitational anomalies, such as gravitational lensing and changes in the rate of expansion of the Universe. The problem of direct detection is that physicists still do not know what makes up dark matter. We only know that it cannot be particles of the Standard model. Scientists believe that dark matter consists of particles that pass freely through the ordinary is not very sensitive detectors, but cumulatively they have a large enough mass to affect the substance macroscopically through gravitational interaction.
Theoretically, to register such an elusive particle possible, if you build a large area detector which contains a lot of atoms. Watching the detector long enough, you can catch not only the gravitational anomalies — collisions between dark matter particles and ordinary matter are very rare, but not impossible. The XENON1T detector refers to the type of plant and is the most sensitive detector of dark matter to date. As a working body uses 3.2 tons of chilled liquid xenon.
On the website XENON1T collaboration, the scientists reported on the results of the latest experiment, researchers first saw the installation thedetective anomalously large number of events. Physicists do not claim to have discovered dark matter, because the event source has not been determined. Informed detector, having spent 279 days, have not shown the existence of winow with energy from 6 to 200 GeV, the main candidates for hypothetical particles of dark matter.
When a particle crosses the target XENON1T, it creates a weak excitation in xenon atoms. Most of these interactions comes from the known particles, so scientists carefully calibrate the number of background events in the installation. This time XENON1T data were compared with calibrated background noise, it was observed excess of events of almost 23 percent.