She works on detectors that look for answers on the origin of the universe

When Archana Sharma first came to Cern (European Organisation for Nuclear Research), on the border of France and Switzerland, to participate in a workshop in 1987, little did the woman from Jhansi know that the place would not only become her home but also make her a specialist in particle physics.

Sharma, now a staff scientist at Cern, and part of the CMS team that discovered the Higgs Boson in 2012, has been instrumental in building one of the most sensitive detectors, the Muon detectors, critical for the search of the origin of the universe.

The first visit, when she was doing her Ph.D, kindled her passion and won her a year-long stay. Having learnt the theories of nuclear physics during her M.Sc and Ph.D, she later got some hands-on experience in the subject. A second Ph.D followed, this time from the University of Geneva. She went on to work on detectors and became an authority on the subject. A few years after she got married and had her son, Sharma was chosen for a position at Cern.

Primordial quests

“It was challenging to do a Ph.D in a place where I had to get through exams in French, a language totally alien to me. Designing and building detectors from scratch was another tough task. There was no weekend, no holidays, and with a young child, it was an uphill task. But I had to take these challenges head on,” Sharma recalls.

The struggle of course set her on track to explore the most primordial quests of humankind — where did we come from? What is the origin of the universe? “Here at Cern, we try to recreate the conditions of the Big Bang by accelerating particles. We give them energy and when these particles collide with each other, for a moment, the particles that existed at the time of the Big Bang are recreated, decaying into particles that we know. So, we need to track these particles from the collision point and the detectors — gas detectors, silicon detectors, pixels detectors and calorimeters — measure the positions, the time and energy and momentum of these particles,” Sharma explains.

To make the Higgs Boson, a lot of energy is needed. So the accelerators needed to be designed in a manner in which there is a high probability of seeing the Higgs Boson. So two very big multipurpose experiments, CMS and Atlas, were set up by Cern between 1992 and 1993. Sharma joined the CMS experiment in 2003 and became a part of the community that was looking for the Higgs Boson.

FACT FILE Bachelor’s in nuclear physics from BHU; Ph.D in particle physics from Delhi University; D.Sc in instrumentation for high energy physics from the University of Geneva

Pioneer of simulations and experimentation on wire chambers, resistive plate chambers and micro-pattern gaseous detectors

Founder and leader of CMS Gem Collaboration for exploiting one of the most sensitive detectors in the CMS experiment at LHC

Runs an NGO called Life Lab Education and Research Foundation to partner with educational institutions to help the underprivileged

Billions of collisions are needed to extract one Higgs Boson — it is like finding a grain of sand on a beach. This was the first time an experiment like this was being attempted. This needed really effective detectors and this was the task Sharma was engaged in. All parameters had to be correct, as did the material and magnetic fields.

Her energy is boundless — be it in exploring new areas of particle physics, setting up new outreach programmes to generate interest in science, building capacity back in India,organising a get-together of Indian students at Cern at her picturesque home near the research facility, or caring for her ageing mother.

Thank you, ma’am

She attributes her success largely to her teachers. “My school teachers in Jhansi charged me into being very excited about physics. At Banaras Hindu University, I had another very good set of teachers, who crystallised the desire in me to follow physics further. I had an extremely good teacher in nuclear physics and the kind of experimental work I did with him for my master’s thesis got me interested in the subject. Then for my Ph.D at Delhi University, I chose experimental particle physics and enjoyed it very much.”

Sharma has consolidated and triggered a new upgrade programme for the CMS Muon system using a brand new technology, engaging a number of Indian institutions — Bhabha Atomic Research Centre, Saha Institute of Nuclear Physics, Panjab University and Delhi University. She was elated when the upgrade was approved. She often travels to India spreading the word about Cern’s mega science projects .

A major facilitator of Indian collaboration with Cern, Sharma is the fulcrum of most Indian activities at the institution.

From just a few Indian students in the 90s, there are some 50 Master’s, Ph.D and post-doctoral students thronging the institute today. And Sharma has been instrumental in many of them earning a place here.

And the students look up to “Archana ma’am”. “It would be a crime if I did not use my privilege to give back to my country,” she says.

The writer is a J.N. Tata Fellow and editor of DST communication at Vigyan Prasar.