Press Release

Press Release from the European Spallation Source neutrino Super Beam ESSnuSB

Issue date: 15th January 2018, Lund, Sweden

WHY DOES THE UNIVERSE EXIST?

Today saw the launch of a European scientific collaboration, ESSnuSB, aimed at discovering why the Universe, as we experience it, actually exists. The collaboration, which is led by researchers from Uppsala in Sweden and Strasbourg in France, is composed of scientists from 11 European countries and is financed by 3M€ from the Research Infrastructure Development Programme of the European Commission.

The kick-off meeting of the ESSnuSB collaboration is being held today in Lund, Sweden, where the very powerful proton accelerator of the European Spallation Source (ESS) is now being constructed. For the next 4 years the international team of ESSnuSB scientists will assess the feasibility of creating the world’s most intense beam of neutrinos, using the ESS accelerator as the driver. These neutrinos, travelling like waves on the sea, but imperceptibly, will pass through the earth’s crust to be detected in a huge 1 million tonne detector housed in an underground cavern located 1 km below the surface of the earth in the Garpenberg mine in Dalarna in central Sweden, more than 500 km from Lund. During their journey, these ghostly neutrinos will, rather remarkably, change their character; a character known to scientists as “flavour”. The discovery that neutrinos oscillate was awarded the 2015 Nobel Prize in Physics. A more precise study of the way in which they do so, now proposed by the ESSnuSB collaboration, promises to give fundamental insights into why the Universe consists only of matter and no antimatter.

Scientists believe the huge and equal quantities of matter and antimatter that were created in the Big Bang 13.6 billion years ago annihilated each other very soon after the Big Bang. However, as there is matter and no antimatter in the Universe today, some small excess fraction of matter must have remained after this massive annihilation event. Why? For this to happen, a slight imbalance in favour of the survival of matter and not antimatter must have appeared just after the Big Bang. A strict requirement for such an imbalance between matter and antimatter to appear is so-called neutrino CP violation, a phenomenon that has so far not been experimentally observed. It is the existence of this phenomenon that ESSnuSB intends to discover and measure. Without such CP violation, all matter and antimatter would have annihilated after the Big Bang and the Universe as we know it today would not exist.

Marcos Dracos, Director of Research at IN2P3-CNRS in France is the ESSnuSB Project Coordinator. He says “This project, aiming to observe CP violation in the leptonic sector together with a very rich astro-particle physics programme, gathers 15 European institutes in a common goal. The project is also supported by the COST Action EuroNuNet ‘Combining forces for a novel European facility for neutrino-antineutrino symmetry violation discovery’.”

Professor Tord Ekelöf from Uppsala university, who is the originator of the idea to use the world’s uniquely powerful ESS accelerator to facilitate the discovery of neutrino CP violation, is the Scientific Leader of the project. He says “Neutrinos are the smallest building blocks of our Universe and the most numerous. They are everywhere in vast numbers – even passing through us now in their billions – and yet they remain an enigma. This very ambitious project – the most intense and the most precise of its kind in the world – promises to reveal subtle details of their behaviour, which will lead to a much deeper understanding as to why our Universe, in all its majesty, exists and indeed why we exist.”

For further information please contact:

Prof. Tord Ekelöf
Tord.Ekelof@physics.uu.se
+46 70 425 0210

Dr Marcos Dracos
marcos.dracos@in2p3.fr
+33 38810 63 70