Physicists Zvi B awardedern, Lance Dixon and David Kosower of the
Galileo Galilei Medal 2023il award awarded every two years by‘National Institute of Nuclear Physics (Infn) with the Galileo Galilei Institute (Ggi), its National Center for Theoretical Physics in partnership with the University of Florence, to male and female researchers who have made an exceptional contribution to the progress of research in theoretical physics. The Prize, announced today February 15, on the anniversary of the great scientist Galileo Galilei’s birthday, was assigned to Zvi Bern – professor and director of the ‘Mani L. Bhaumik’ Institute for Theoretical Physics of the University of California, Los Angeles – Lance Dixon – professor of theoretical physics at Slac Stanford Linear Accelerator Center of Stanford University and member of the US National Academy of Sciences – and David Kosower – researcher at the Institut de Physique Théorique del Cea in Saclay, France . The prize was awarded to the three physicists “for the development of powerful methods for high-order perturbation computation in quantum field theory”. Lance Dixon recalls that “in the early 1990s there was a problem: trying to make the most of the particle colliders under construction, such as LHC at Cern”. “A collider – explains the scientist – is a very complicated machine built to try to learn the secrets of nature: it collides protons, composed of quarks and gluons, which interact with each other through a force, called strong force, which theorists of particles call Qcd, Quantum Chromodynamics, where chromium corresponds to the colors of the quarks and gluons exchanged in collisions”. “And we – he underlines – were able to convert a property of Qcd, known as unitarity, into a tool useful for making more precise calculations, both for LHC processes and for simpler ones”.
“Initially – adds David Kosower – our goal was to refine and improve the theoretical tools available to experimental physicists in particle physics. We then developed new and more efficient methods to perform theoretical calculations. These methods allowed us to perform many more calculations and to achieve much higher precision than was previously possible”. Kosower points out that “these developments have allowed a new generation of researchers to continue developing new techniques and new calculations for Lhc but also to create connections with many other branches of physics: new very interesting connections have arisen between theories such as quantum chromodynamics and the gravity”. Commenting on the Prize, Zvi Bern recalls that “when David Kosower, Lance Dixon and I started thinking about the so-called scattering amplitudes, it seemed to most that all the important ideas had already been developed. In the 1950s and 1960s, l The topic wasn’t of much interest, but the three of us had a different point of view.” “The path to convincing the community that there was something profound and interesting in scattering amplitudes – continues the physicist – was not easy: when we started, all the people interested in the subject could fit in a small closet. Now, instead, the problem is finding rooms large enough for lectures and workshops. I always marvel that we are no longer the only ones who find joy in studying this subject.”
“My sincere congratulations to the winners of the Galileo Galilei Medal 2023, who are also great friends of ggi, having contributed a lot to the institute’s activities with their participation in various research programs and conferences” comments Stefania De Curtis, director of ggi highlighting that “the work of Bern, Dixon and Kosower has played a central role in improving our ability to compare theory and experiments at particle colliders, but also to extract information from gravitational wave observatories”. Finally, De Curtis observes that “physicists often tend to consider exceptional results those deriving from new theories that arise from new principles. However, sometimes these arise from a careful reinterpretation of already known principles. This is the case of the exceptional results obtained by Bern, Dixon and Kosower: a revolution in our understanding of the processes involved in particle collisions, which greatly improves our ability to uncover the underlying physical phenomena”.
(by Andreana Aquinas)