Fundamental Interactions in Low-Energy Systems

The fourth course of the International School of Physics of Exotic Atoms took place at the "Ettore Majorana" Center for Scien­ tific Culture, Erice, from March 31 to April 6, 1984. As tradition, exotic atoms have been a tool for studying elec­ tromagnetic, weak and strong interactions at low energies. We felt it appropriate to have a full course devoted to a discussion of the information to be gained on the fundamental interactions from the study of low energy systems. In this kind of physics, which is characterized experimentally by very intense particle sources and very sensitive apparatuses, one can search for rare events and can perform precise measurements. Sensitive tests of the predictions of current theories of electro­ weak and strong interactions can thus be achieved. The course was attended by 54 participants from 23 institutes in 9 countries. The morning lectures reviewed the achievements of the field in the last few years and the afternoon seminars dealt with new results and projects.

I The Electro-Weak Force at Low Energy.- Weak Interactions at Low Energy.- Determination of the Muon Decay Parameters.- Measurement of the ?-Parameter in ?-Decay.- Muon Capture in Hydrogen.- Muon Capture in Deuterium.- Parity Violation in Atoms.- Neutral Currents in Muonic Atoms.- Rare Muon Decays and Lepton-family Number Conservation.- Neutrino Masses and Mixing from Neutrino Oscillations.- Searches for Mixed Heavy Neutrinos in Meson Decays and in Muon Capture.- II Strong Interactions.- The Exotic Atoms of QCD: Glueballs, Hybrids and Baryonia.- Quarkonium Spectroscopy.- The LEAR Physics Programme.- Electron-positron Pair Production in $$p\bar p$$ annihilation at LEAR.- $$p\bar p$$ Annihilations at Rest in Hydrogen Gas: Report on Preliminary Results of the Asterix Experiment at LEAR.- First Physics Results from Experiment PS172 at LEAR.- Antiproton-proton Reactions in the Momentum Range from 250 to 600 MeV/c.- X-rays from Protonium — PS 174 Progress Report.- Antiproton X-ray Spectroscopy in the Cyclotron Trap: Preliminary Results.- PS184: A Study of Antiproton-nucleus Interactions at LEAR.- Perspectives of Antineutron Physics.- III Search for Hypothetical Particles and Interactions.- Weakly Charged Exotic Particles.- Search for Muon-hadron Interactions from Muonic X-rays.- Experimental Search for Strong van der Waals Forces.- Photon-photon Interaction Detection via the Vacuum Birefringence Induced by a Magnetic Field: Status of the Experiment.- IV Perspectives of Superconducting Junctions in Nuclear and Particle Physics.- Potential of Superconducting Tunnel Junctions as Detectors in Nuclear and Particle Physics.- Development of a High Resolution Superconducting Detector for keV Radiation at SIN.- New Detectors and Neutrino Mass.- V Some Aspects of the Physics ofMuonic Atoms and Molecules.- Different Facets of Muonic Molecules.- New Experimental Results on Muon Catalyzed Fusion in Low Density Deuterium-tritium gas.- Progress in Muon Catalyzed Fusion at JINR in Dubna (USSR).- Triplet State Lifetimes and Muon Capture in Gaseous Hydrogen.- Formation of the Lightest Muonic Atoms and the 2S-lifetime of the (??4He)+-ion.