- The Synergy-2020 NEXT-BOLD project aims to discover whether the neutrino is its own antiparticle, and thereby to answer fundamental questions about the origin of the universe.
- Researchers of DIPC, UPV/EHU and Ikerbasque, with the participation of Harvard University, obtain the first ERC Synergy for the Basque Country, with a budget of close to 10 million euros.
- The ERC Synergy Grant is one of the most prestigious research grants in the world, whose purpose is to undertake pioneering, cutting-edge research, by creating synergies between different areas of knowledge.
In 2007, the European Commission created the European Research Council (ERC) with the aim of promoting excellent basic science in Europe, supporting the best researchers in all fields and of any nationality who wish to continue their research at the frontiers of knowledge. The ERC funds prestigious projects that seek to develop innovative and high-risk research. Since its creation, the ERC has had a substantial impact on the European research landscape.
Of all the grants awarded by the European Research Council, the ERC Synergy is the most competitive, with a success rate of less than 10%. Its purpose is to enable a small group of principal investigators and their teams to bring together complementary skills, knowledge and resources in a novel way to jointly address major research challenges.
The Synergy-2020 NEXT-BOLD project has been awarded to Juan José Gómez Cadenas, Ikerbasque Professor of Physics at Donostia International Physics Center (DIPC), Fernando Cossio, Professor of Chemistry at the University of the Basque Country (UPV/EHU) and scientific director of Ikerbasque, and Roxanne Guenette, Assistant Professor of Physics at Harvard University. It is endowed with 9.3 million euros and will last for 6 years. It is the first project of these characteristics that Basque institutions have obtained.
The Synergy-2020 NEXT-BOLD project and its fundamental questions
According to the philosopher and mathematician Leibniz, the fundamental question is: “Why does something exist instead of nothing?” Today, this question is formulated in more specific terms: “Why is our universe made of matter? Why does everything exist as we know it?” This brings us to one of the most important unsolved problems in particle physics, and thus in chemistry. This problem is that of the nature of the neutrino, which could be its own antiparticle, as the unfortunate Italian genius Ettore Majorana ventured almost a century ago. If this were so, it could explain the mysterious cosmic asymmetry between matter and antimatter.
In words of Fernando Cossio, “in science, the most complicated thing is to ask a big question that is difficult, but not impossible to answer”. In this sense, Juan José Gómez Cadenas has said that “for me it has two extremely positive aspects: on the one hand, getting an ERC Synergy provides the necessary resources to tackle what I consider the most important scientific challenge of my career. On the other hand, it allows me to firmly establish a new interdisciplinary line, developed in collaboration with Fernando Cossio in the Basque Country. I have the curious notion of feeling a connection between the team formed by Fernando and myself and the Elhuyar brothers. Hopefully, we can aspire to make a discovery as significant as theirs”.
Indeed, we know that the Universe is made almost exclusively of matter. However, the Big Bang theory predicts that the early Universe contained the same amount of matter and antimatter particles. This prediction is consistent with the “small Big Bangs” that form in proton collisions at CERN’s giant LHC accelerator, where a symmetrical production of particles and antiparticles is always observed. So, where did the antimatter of the early Universe go?
A possible mechanism regarding the destination of early-Universe antimatter points to the existence of heavy neutrinos that were themselves their own antiparticles, and therefore, could decay into both matter and antimatter. After all the matter and antimatter in the Universe were annihilated (with the exception of a small excess), the result would be a cosmos made only of matter, of the leftovers of the Big Bang. We could say that our Universe is the remnant of a cosmic shipwreck.
NEXT: precedents of the NEXT-BOLD experiment
It is possible to demonstrate that the neutrino is its own antiparticle by observing a rare type of nuclear process called “neutrinoless double beta decay”. This process can occur in some rare isotopes, such as xenon-136. The NEXT experiment —proposed by Gomez-Cadenas and co-led by Gomez-Cadenas and David Nygren, presidential chair at the University of Texas at Arlington, looks for these decays using high pressure gas chambers.
So far, NEXT was focused on observing the characteristic signal emitted by the two electrons resulting in the mentioned decay, but this signal is extremely weak and could be eventually masked by the background noise due to the ubiquitous natural radioactivity. However, if in addition to observing the two electrons, the barium ionized atom, which is also one of the products of xenon disintegration, is detected, we would have the unequivocal signal we are looking for, and the experimental evidence that the neutrino is indeed its own antiparticle.
Therein lies precisely the challenge faced by the NEXT experiment, in identifying this single barium atom. The possibility was proposed by David Nygren in 2016, and the NEXT collaboration proposed a first proof of concept in 2017. In 2020, Cossio and Gómez-Cadenas led an interdisciplinary team which demonstrated the feasibility of a large-scale experiment based on a new type of molecules, capable of capturing the barium ionized atom and providing an unmistakable signature (sifting their characteristic emission spectrum) when this occurs. The results were published in the prestigious journal Nature. But, in a recent collaboration between Fernando Cossio and Juan José Gómez Cadenas, published in the same journal, they have shown that it is possible to capture the barium atom with a molecule capable of forming a supramolecular complex with it and to provide a clear signal when this occurs.
The goal of the Synergy-2020 NEXT-BOLD project is to design, develop and build a new generation of the NEXT detector with the capability to detect the barium ion, based on a molecular fluorescent indicator and advanced microscopy techniques. This experiment would have a great potential to discover if the neutrino is its own antiparticle, which would allow to answer the fundamental questions about the origin of the universe.
Image and media credits:
Frontpage ESO Schmidt Telescope picture of the Tarantula Nebula in the Large Magellanic Cloud showing Supernova 1987A was downloaded and edited from the version at Wikipedia and licensed via a Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) license.
All other pictures and media kindly provided by DIPC and re-used with permission. Of these, picture of Fernando Cossio and Juan José Gómez Cadenas taken by Ángel L. Fernández and picture of Roxanne Guenette taken by Marina Werbeloff.