Dark matter is one of the basic ingredients of the universe. There is five times more dark matter in the universe than normal matter, the atoms and molecules that make up everything we know, yet it is still unknown what this dominant dark component actually is. Searches to detect it in laboratory-based experiments have been conducted for decades. However, dark matter has been observed only indirectly via its gravitational interactions that govern the dynamics of the cosmos. Scientists believe that dark matter is made of a new, stable elementary particle, which has escaped detection. So far.
On November 11, an international collaboration of scientists unveiled an instrument designed to search for dark matter with unprecedented sensitivity. XENON1T is located inside the largest underground laboratory in the world for astroparticle physics. Gran Sasso National Laboratory in Italy sits under 1400 meters of rock to shield the dark matter detector from cosmic rays and environmental radiation.
XENON1T employs ultra-pure noble gas xenon as dark matter detection material cooled down to –95°C to make it liquid. The large-mass instrument features an extremely low radioactive background in order to be able to identify rare events from a dark matter interaction. For this reason, XENON scientists have carefully selected all materials used in the construction of the detector, ensuring that their intrinsic contamination with radioactive isotopes meet the experiment's strict low background requirements.
XENON1T measures tiny flashes of light and charge to reconstruct the position of the particle interaction within the detector, as well as the deposited energy and whether it might be induced by a dark matter or not. The light is observed by 248 sensitive photosensors, capable of detecting even single photons.
Scientific Game Changer
Once fully operational, XENON1T will be the most sensitive dark matter experiment in the world. The first set of scientific results are expected in early 2016. The XENON program group consists of 21 research groups from the US, Germany, Italy, Switzerland, Portugal, France, the Netherlands, Israel, Sweden and the UAE.
NYU Abu Dhabi is an active partner through the research group led by Francesco Arneodo, associate professor of physics, who joined NYUAD in 2013 after spending 20 years at the Gran Sasso Laboratory and more than a decade working on the XENON project. The NYUAD group is responsible for the TPC resistor chain—a key element of the detector—water purification of the 10-meter shield, and for offline data quality monitoring. NYUAD researchers will be also on the frontline data analysis team when the first scientific results are reported next year.
NYUAD's research group: Francesco Arneodo (PI), Mohammed Lotfi Benabderrahmane (lecturer), Adriano Di Giovanni (scientist), Ioana Maris (postdoctoral associate) and Valerio Conicella (technician). Numerous NYUAD students are involved in the research program.