Aldo Menzione 1943–2012

Aldo Menzione, a pioneer in the development and use of silicon vertex detectors, passed away quietly and unexpectedly in Pisa on 23 December 2012.

Aldo graduated in physics in 1967 with a thesis on "Production of Neutral Mesons Decaying into All-neutral secondaries" at the CERN Proton Synchrotron and in 1969 joined the Pisa-Stony Brook collaboration at the Intersecting Storage Rings (ISR). This experiment discovered that the total proton–proton cross-section starts increasing at ISR energies, a departure from what had previously appeared to be a flat "asymptotic" behaviour. Aldo made important contributions in setting up the experiment and in the study of short-range correlations among particles produced in inelastic collisions, which were observed by the same experiment for the first time as an early manifestation of hadron jets.

In 1978, as a member of the Pisa team, Aldo designed and built the small-angle spectrometer of the NA1 (later NA7) experiment. This spectrometer obtained the most precise measurements of the pion and kaon charge-radius, as well as a number of new results in charm physics. The tracking system of NA1, to which Aldo devoted much of his effort, used one of the first active targets of silicon detectors and later an innovative germanium-strip detector to identify the decay of long-lived charmed hadrons, allowing measurement of their lifetimes. From this, Aldo understood that a silicon-strip vertex detector could be used to signal the decays of charmed and beauty hadrons close to the vacuum pipe at a hadron collider, thereby tagging jets containing heavy flavour.

Starting in 1980, he began work on the detailed design of the CDF detector at Fermilab’s Tevatron with his characteristic vigour, originality and vision. Aldo was leader of the Silicon Vertex Detector construction project, which played an essential role in the discovery of the top quark in 1995 by identifying the b quarks from top decays. For Run 2 of CDF, an upgraded vertex detector was implemented with fast front-end trigger electronics, which allowed operation of a displaced vertex trigger, the Silicon Vertex Trigger (SVT). Aldo and the prime designer of the SVT, Luciano Ristori, were awarded the 2009 Panofsky Prize in Experimental Particle Physics of the American Physical Society in 2009 for "their leading role in the establishment and use of precision silicon tracking detectors at hadron colliders, enabling broad advances in knowledge of the top quark, b hadrons, and charm hadrons" (CERN Courier December 2008 p34).

Besides being an extremely skilled experimentalist, Aldo was warm, direct and a wonderful colleague and friend. He participated actively in physics discussions with crisply thought-out, bluntly expressed and often deeply original contributions. Aldo created a special atmosphere in which the best decisions were made and everybody, including the junior members, felt included.

• Adapted with permission from material that originally appeared in Physics Today’s Daily Edition, www.physicstoday.org/1.2902567.


Ger van Middelkoop 1937–2013

Ger van Middelkoop, an experimental nuclear and particle physicist with a talent for scientific leadership, passed away on 4 February after unexpected heart failure.

Ger studied and worked at Utrecht University, obtaining his PhD in 1966 with Pieter Endt for work on neutron capture, research performed at the Reactor Research Facility in Petten (now known as Energy Centre Netherlands). He also worked as a postdoc at Chalk River Nuclear Laboratories in Canada.

In 1979 he was appointed as professor in experimental physics at the Vrije Universiteit in Amsterdam. In the following years he played a key role in the merger of the separate Nuclear Physics and High-Energy Physics sections into what is now the National Institute for Subatomic Physics (Nikhef). He was scientific director of the Nuclear Physics section for several years (1983–1988) and later the first scientific director of the combined Nikhef institute (1996–2001). He managed to bridge the cultural differences between the sections with his direct but also amiable style.

Ger was the driving force in the participation of Nikhef in the New Muon collaboration (NA37) at CERN and was spokesperson from 1990 until 1995. Besides his managerial work, he always kept close contact with the ongoing work of PhD students and colleagues at the laboratory – often walking in and discussing physics even when they were working late. Many colleagues remember him as someone who carefully read and corrected publications and thesis manuscripts, and who was always stimulating staff and students to attend weekly colloquia at the institute, where he himself enlivened the discussion with sharp questions.

Later in his career and after his retirement, he stayed active in the field. He led the organization of the 2002 International Conference on High-Energy Physics in Amsterdam, was active in scientific advisory boards as well as organized and participated in various physics outreach activities in the Netherlands. After a difficult period in his personal life, in which he lost his wife, he organized and enjoyed with his new partner various cultural activities in their second home in France.

His friends and colleagues.