From the June 1975 issue

Fourth CERN-JINR School

The fourth Joint JINR-CERN School of Physics, generally regarded as the most successful yet, took place at Alushta in the Crimea, USSR, from 14 to 28 May 1975. About 60 students attended from Dubna and its Member States and 35 from CERN and its Member States. Lecturers from Western Europe were C Michael from the University of Liverpool, L Montanet and W Jentschke from CERN, and B Wiik from DESY.

  • Compiled from texts on p191.

First patient irradiations

The use of particle beams for cancer therapy has been studied for 10 years. In May, preliminary results of the first-ever patient irradiations using negative pion beams were reported at a meeting in San Juan, Puerto Rico.

Irradiations on two patients exhibiting tumour nodules in the skin began in October 1974 at the Los Alamos 800 MeV proton linear accelerator, LAMPF. They were conducted by the Cancer Research and Treatment Center of the University of New Mexico in collaboration with the LAMPF team.

The paper to the American Radium Society reported no unusual reactions from the treatment. It seems that pions can achieve an equivalent effect on tumour tissue with about half the X-ray dose needed and less damage on normal skin in the irradiated areas.

  • Compiled from texts on p93.

Adone and the new particles

When news of the discovery of the 3.1 GeV particle [the J/ψ charm/anti-charm meson] reached physicists at Adone, the e+e storage ring at Frascati, an intense programme was started to push beam energies above the nominal top energy of 1.5 GeV per beam. Thanks to the joint efforts of the machine group and experimental teams, a clear signal of the new particle was observed within a few days (CERN Courier December 1974 p417).

Simultaneous measurements of the total and the leptonic cross sections give information on the intrinsic width of the particle (linked to its stability). The Frascati group have now published results indicating a total width less than 100 keV. At present an extensive search is in progress for narrow resonances in the mass range 1.90 to 3.15 GeV.

  • Compiled from texts on pp193–194.

ECFA urges European e+e ring

At a Plenary Meeting on 6 June, ECFA, the European Committee for Future Activities (formerly the European Committee for Future Accelerators), passed a resolution in support of the construction of a higher energy e+e storage ring in Europe.

The statement reads — “ECFA considers that

i) electron–positron storage rings with centre of mass energy above 20 GeV would be an extremely valuable addition to European high energy physics facilities, complementing existing proton accelerators and national electron–positron facilities at lower energies,

ii) it is of primary importance that such a project is realised with minimum delay,

iii) the exploitation of the storage rings should be open to the European scientific community,

iv) there should be no duplication of similar accelerators within Europe. If the laboratories concerned agree, ECFA will study and make recommendations about the international exploitation of such a facility.”

Concern for an early start on one of two European projects under discussion, PETRA [DESY] and EPIC [Rutherford Laboratory], is related to an equivalent USA project at Berkeley/Stanford, PEP. The new particle discoveries hold out the tantalising prospect that the first machine to operate could cream off some spectacular physics.

  • Compiled from texts on p198.

Compiler’s note

Following the 1974 discovery of charm at the e+e collider SPEAR at SLAC (and at BNL, using a proton beam from the Alternating Gradient Synchrotron), there was indeed more spectacular physics to come from a lepton collider – the ground-breaking discovery of the gluon at PETRA. In 1976 a trio of CERN theorists, John Ellis, Mary Gaillard and Graham Ross, suggested that gluon bremsstrahlung might appear in 3-jet events from e+e annihilation. In 1979, within a year of PETRA commissioning, all four experiments – Mark J, JADE, PLUTO and TASSO – had evidence for the existence of this hitherto hypothetical particle, the first gauge boson to be detected after the photon.

 

About the author

Compiled by Peggie Rimmer