In memoriam Martinus ‘Tini’ Veltman (1931-2021)

6 January 2021

The influence of Martinus Veltman on particle physics is difficult to overestimate.  Non-abelean gauge theories now form the basis under the Standard Model. Experimental particle research worldwide is largely inspired by his research and follow-up. He has supervised a number of PhD students, each of whom has made a name for himself in the field.

From the neutrino postulate in the 1930’s there was a theory that only gave unambiguous results in the lowest order. Higher order calculations gave infinity that could not be absorbed in redefinitions as quantum electrodynamics could. Veltman played a pioneering role in solving this problem.

By analyzing what was known at the time as current algebra, he made it clear that in theory the spin-1 particles had to comply with a Yang-Mills structure. In order to be able to perform a renormalization program like QED, he looked at alternative Feynman rules with unphysical scalar particles, so-called ghosts.

On that basis Veltman was able to prove renormalization of the electro-weak theory to 1-loop. Finally, Gerard ‘t-Hooft proved that renormalization to all orders is possible if a new physical particle is introduced. A particle that is now known under the name Higgs-boson. It has provided the foundation for extensive experimental research at CERN (LEP and LHC) and elsewhere in the world.

Tini, the name with which he was mostly addressed, was born in 1931 in Baardwijk in Noord-Brabant (now part of Waalwijk). His father was principal of the elementary school which was in the same street as his parental home. In 1948 he graduated HBS-B, his physics teacher encouraged him to study physics at the university.

At Utrecht University his interest seemed to be in experimental physics. After Leon van Hove’s appointment he decided to study theory. During his doctoral studies he had an appointment as assistant at the van der Waalslab in Amsterdam.

After his graduation on 26 November 1956 the military was inevitable.  As a graduate physicist he was placed with the staff of the Air Force where he occupied himself with the interpretation of radar images. The important question was how many aircraft arrived from the east.

After his military service Van Hove offered him a promotion place. The promotion work started in Utrecht. With the departure of Van Hove to CERN Veltman went with him. The first chapter of his PhD thesis was already finished and was a technical consideration of unitarity in field theory.

At CERN Tini met the American physicist Sam Berman. He introduced Tini to neutrino physics, which laid the foundation for the second chapter of his thesis. Besides the influence of John Bell, Tini has always emphasized the role of Berman in his scientific career.

At that time Tini also worked closely together with the experimental (neutrino)physicist Bernardini. In 1961 Veltman presented CERN’s experimental results at a conference in Brookhaven. His contribution made an impression. From that moment on Veltman was a renowned physicist in the United States.

In 1963, Veltman received his doctorate from Utrecht University and remained at CERN until 1966. In 1963/1964 he visited SLAC in the USA, partly because Sam Berman was working there at the time. During his time at SLAC he made a start with his computer algebra program SCHOONSCHIP, a predecessor of programs such as Mathematica, Maple and FORM.

In 1966 Veltman was appointed ordinary professor at Van Hove’s still unoccupied chair in Utrecht. With his arrival in Utrecht the subject of theoretical particle physics or theoretical high-energy physics was introduced in the Netherlands.

Tini was not only involved in the theoretical side of the subject. Through his work at CERN and his experimental interest he also served the interests of experimental high-energy physics. He stood, together with others, at the cradle of Nikhef. He himself wrote the article “The gang of four” there in 2010, which can be found in the Nikhef annual report.

In 1981 Veltman left the Netherlands for a professorship appointment at the University of Ann-Arbor. Shortly after his appointment there he was honored with the prestigious MacArthur endowment. He worked there until 1996 and then returned to his old hometown Bilthoven, where he died on Monday 4 January.

(Karel Gaemers / Bernard de Wit)