Born in Kenya, now commuting between the Alps and London, Professor Tejinder Virdee is a particle physicist working at the CMS experiment at CERN.

Born in the foothills of Mount Kenya, now commuting between the foothills of the Alps and London, Imperial's Professor Tejinder Virdee is a well-heeled citizen of the world. Over the last 30 years his work as a particle physicist has taken him around the globe while championing a border-crossing experiment that has changed the face of physics and our understanding of the Universe.

Tejinder’s globetrotting began when he was a postgraduate at Imperial, with trips to America’s national accelerator laboratory in Stanford to collect data for his PhD (Physics 1979). “At the time, few universities offered this kind of opportunity for a young student to travel on the job, but there were only a few places where you could do large scale particle physics experiments,” he explains.

These early experiences inspired Tejinder to move from London to the European Organization for Nuclear Research (CERN) in Geneva, Switzerland, where he pioneered new approaches to high energy physics. By 1989 CERN’s Large Hadron Collider project was beginning to get going. Tejinder worked with colleagues to develop the proposal for an experiment that, in 1993, was chosen over stiff competition from scientific rivals as the best way to detect the now famous Higgs boson particle.

And so it was that this young experimentalist and self-made inventor of particle detectors found himself as deputy project leader of the Compact Muon Solenoid (CMS ) experiment – the project to design a new particle detector that has since become known as the ‘united nations of science’, involving over 3,000 scientists and engineers from 40 countries.

The experiment called for input from institutions and governments in many countries, which Tejinder and his colleagues set off to visit one by one. “We had grand scientific goals, and went on a journey of discovery to countries such as Brazil, China, India, Iran, Korea, New Zealand, Pakistan, Ukraine, USA and more,” he recalls. “Everyone treated us really well, and each trip held a new surprise. In Beijing we were taken to the Forbidden City before our meeting. In Taiwan I found myself in the middle of an earthquake. And in India we stayed in a makeshift bed and breakfast where the villagers still hand weave beautiful shawls.”  The scale of the CMS project meant it would take almost 20 years to complete.

One of his early trips turned up a key component for the detector in the form of lead tungstate crystals in the former USSR . “I knew these would be perfect for measuring the high energy photons so vital in our search for understanding how elementary particles acquire mass,” Tejinder remembers. “Manufacturing the crystals turned out to be our biggest challenge. It took 20 visits to Russia and earned me an open visa, but we eventually got them grown in an ex-military factory outside Moscow – a production that ran round the clock for 10 years.” It also turnedout to be the project’s biggest contract, worth 50 million Swiss francs. “We initially settled in US dollars, but the changing economy meant that final payments were made in Russian roubles.” It turned out to have been a good investment though, as it was in these very crystals that CMS detected the strongest signal for the new boson.

All the while he was away, Tejinder kept up strong connections with Imperial: “I have always felt part of the Imperial family,” he says. “It is one of the few places in the world that could have let me do the research I wanted. Everyone has been very supportive and we are known the world over as a leader in particle physics.”

After almost two decades at the helm of CMS , Tejinder now devotes his time to extracting the science from CMS and spending more time at Imperial. His home remains in Geneva with his wife Vatsala, who works for the United Nations. “When I’m travelling I stay in hotels, but it’s much more pleasant when you have your own place to go to. London is refreshing and I can focus on teaching.” It’s also a chance for him to catch up with his children, Oxford astrophysics doctoral student Jasmeer (Physics 2009) and primary school teacher Natisha, who both moved to the UK for university after growing up in Switzerland.

So where next for Tejinder? He was just back from a meeting in Edinburgh with only a small suitcase when Imperial magazine met up with him. He left promptly to board a plane to Corsica to talk about the results on the recently discovered Higgs-like boson, to be followed by a CMS symposium in Lisbon, Portugal, and then on to Krakow, Poland to discuss the future of particle physics. “This is an exceptionally busy time for me,” he laughs. “It’s hard to say no to these invitations. It’s always exhilarating to share my passion for particle physics.”

This article first appeared in Imperial Magazine, Issue 38. You can view and download a whole copy of the magazine, from www.imperial.ac.uk/imperialmagazine.