title: On the chemical reaction of matter with antimatter.
abstract: A chemical reaction between the building block antiatomic nucleus, the antiproton (p or H- in chemical notation), and the hydrogen molecular ion (H2+) has been observed by the ATHENA collaboration at CERN. The charged pair interact via the long-range Coulomb force in the environment of a Penning trap which is purpose-built to observe antiproton interactions. The net result of the very low energy collision of the pair is the creation of an antiproton-proton bound state, known as protonium (Pn), together with the liberation of a hydrogen atom. The Pn is formed in a highly excited, metastable, state with a lifetime against annihilation of around 1 micros. Effects are observed related to the temperature of the H2+ prior to the interaction, and this is discussed herein.
authors.affiliation: Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, Università di Brescia, 25133 Brescia, Italy. lodi@bs.infn.it
authors.forename: Evandro
authors.initials: E
authors.lastname: Lodi Rizzini
authors.forename: Luca
authors.initials: L
authors.lastname: Venturelli
authors.forename: Nicola
authors.initials: N
authors.lastname: Zurlo