Physicists from the Department of Physics and the Bologna Section of INFN (National Nuclear Physics Institute) have been conducting research into antimatter for about 40 years.

• 1965: Ten years after the discovery of the antiproton, a group lead by Prof. Antonino Zichichi, using the PS (Proton Synchroton) accelerator of CERN in Geneva, observed for the first time the antideuteron, made of an antiproton and an antineutron. This observation happened at the same time as the one made by American colleagues at the AGS (Alternating Gradient Synchroton) accelerator of the Brookhaven National Laboratory, near New York.
  
• 1978 : Thirteen years later a group lead by Prof. Giorgio Giacomelli, in cooperation with French colleagues, detected more complex antinuclei at the CERN SPS (Super Proton Synchroton): antitritium and antihelium-3, made by an antiproton and two antineutrons and by two antirprotons and one antineutron, respectively. Similar observations were made by Russian groups at the Serpukhov accelerator in Russia.

At the end of the sixties Bruno Touschek proposed colliding positrons with electrons  to study the annihilation features. This led to the construction of the first positron-electron collider AdA at the Laboratori Nazionali di Frascati; it was later followed by a much larger collider, ADONE.

Fig. 2: BCF detector at ADONE. (Credit: INFN)

1969-1974: A group of Bologna physicists was one of the first groups to perform experiments at the Frascati ADONE collider (BCF experiment).

The advantages offered by positron-electron colliders led to the construction of newer and more powerful colliders in the US, USSR and in Europe. The last positron-electron collider was the LEP (Large Electron Positron collider) at CERN, which operated from 1989 to 2000; with its 27 km circumference, it was the largest accelerator ever built.

Fig. 3: Representation of a positron-electron collision at high energies provided by LEP. (Credit: CERN photo-di/9105064)

1989 - 2000: Three groups from Bologna participated in the experiments DELPHI,  L3 and OPAL at LEP, taking precision measurements of all the parameters of the Standard Model of Particle Physics; they established the existence of just three types of light neutrinos.

Parallel to the developments in positron-electron colliders there were also  developments in proton-proton and antiproton-proton colliders.

Fig. 4: One of the intersecting regions of the ISR collider at CERN (Credit: CERN Courier (April 2002))

1981 - 1983: At the Intersection Storage Rings (ISR) at CERN one group of researchers from Bologna, in cooperation with US and European groups, studied antiproton-proton collisions and compared their main features with those of proton-proton collisions.

The possibility of performing proton-antiproton collisions at higher energy using the existing CERN SPS accelerator as a collider was demonstrated in the early '80s; the collider led to the discovery of the W⁺, W¯, Z⁰ particles, which are the mediators of the weak interactions. Carlo Rubbia and Simon Van der Meers won the Nobel prize for this discovery.

Low energy matter-antimatter collisions have also been performed.