Scientists decode Cern spectacle

KOLKATA: After chasing God particles and the universe’s origins in a cavernous tunnel deep underground, it’s back to more mundane things for Sukalyan Chattopadhyay, Pradip Roy and Abhee Dutt Majumdar in Kolkata. The trio were members of the team of scientists that smashed protons and set off the historical experiment at Cern — the European organisation for nuclear research at Geneva, Switzerland — nine days ago. Led by Chattopadhyay, the three senior physicists from Saha Institute of Nuclear Physics (SINP) saw history being created at CERN on March 30. While for the last one year, collisions were happening inside the Large Hadron Collider (LHC), these were happening at a much lesser energy level of 900 GeV. This was the first time that collisions were tried at 7 TeV — unmatched in any experiment ever before. As you read the story, protons collide inside the LHC at Cern, and this will continue to happen till the middle of last year. The success of the March 30 experiment paves the way for the next level of collisions that are due to happen next year at 10 TeV energy level. At the final level when scientists start looking for the God particle or Higgs boson, the collision will happen at 14 TeV in 2013. While the proton beams move in clockwise and anticlockwise directions inside the 27 km LHC, the collisions happen at four points where a large number of detectors track the particles created after the collisions. Two city institutions can take pride in having created two such detectors — the MUONARM detector of SINP and PMD of the Variable Energy Cyclotron Centre (VECC). Interestingly, both the institutions are located on the same campus. Both the city-based detectors are located at the Alice point of collision. “While at two other points of collision, scientists are on the lookout for the God particle, we at the Mounarm detector are aiming at heavier ion (read lead ion) collision. This will give us greater scope to study the particles emanating out of the collision and to map their characteristics,” said Sukalyan Chattopadhyay. “What made the March 30 experiment different is that Cern was able to successfully collide protons at four times greater energy level. Initially there was trouble getting both the beams to move steadily at the desired level inside the LHC as one beam started failing. However around 5:38 p.m. IST, the collision happened,” said Dutt Majumdar. Trying to quantify the impact of this high energy collision, he said, “imagine two cars weighing 60 kilos colliding at a speed of 200 kilometres per hour.” The three scientists that SINP were present to collect data about the particles that emanated out of the proton-proton collision. “None of these particles are unknown as of now. But we are happy to say that we were able to detect a particle called Jpsi, which is critical to our experiment,” said Chattopadhyay. But perhaps what makes SINP most proud is that the chip that it had created, called the Manas chip, is the integral part of both the PMD and Muonarm detectors. “The Muonarm detector was created in collaboration with other countries like Russia, Italy, France, Germany and South Africa, but the chip is ours, which make us extremely proud, every time a collision happens, detectors pick up data and we inch towards the God particle experience,” Chattopadhyay summed up.