New Delhi, March 30: Two needle-thin beams of subatomic particles collided in an underground tunnel in Europe today at the highest energy levels ever achieved in a laboratory as scientists made a fresh bid for deeper insights into the secrets of the universe.
After three hours and one failed attempt this morning, physicists applauded as they produced the high-energy proton-proton collisions inside a giant physics machine, a particle accelerator called the Large Hadron Collider (LHC), at 12.36pm local time in Geneva.
Physicists hope to answer some of the most fundamental questions about the nature of the universe by observing and analysing the antics of billions of other subatomic particles that emerge from the proton-proton collisions. A primary goal of the LHC is to find evidence for a particle called the Higgs boson, predicted decades ago by a theory of physics named Standard Model that seeks to explain the zoo of subatomic particles.
The Higgs boson has been the only missing piece of the Standard Model puzzle, said Satyaki Bhattacharya, associate professor at the University of Delhi, who is among dozens of physicists from India who are participating in the LHC experiments.
All the particles predicted by this theory have been observed except the Higgs boson, he said. Several institutions across India have either contributed hardware for the components of the LHC experiments or will participate in data analysis.
The high-energy proton-proton collisions at the LHC are expected to produce the Higgs boson.
The proton beams collided today at 7TeV (trillion electron volts), half the maximum energy for which the LHC has been designed.
Scientists say that 1TeV is about the energy of the motion of a flying mosquito, but the LHC squeezes that energy into a space about a million million times smaller than a mosquito, creating conditions that existed a billionth of a second after the birth of the universe.
The collision fragments from the LHC are also expected to help physicists investigate theories that predict the existence of extra dimensions, and try to gain insights into the mysterious and invisible dark matter, which is five times more abundant than ordinary matter.
Were about to explore new territory of physics, said Guido Tonelli, a physicist at one of the detectors a component that functions somewhat like a digital camera to analyse the collision events of the LHC, moments after collisions began.
Its exciting the collisions are going on, and were all trying to see the data coming in and to monitor the health of our detectors, Sandhya Jain, a physicist from the University of Delhi, told The Telegraph from a control room at Cessy, France.
Im looking for signatures of extra dimensions, Jain said.
This is a step into the unknown. We are doing something that no one has done before. We hope we find things that are really new, said research director Sergio Bertolucci.
There are known unknowns out there, like dark matter and new dimensions about which we hope to learn. But it is possible that we will find some unknowns which could be hugely important for mankind. With the LHC, we have the tool that we need.
The LHC, which cost about $8 billion to build, may be the worlds largest and most expensive science experiment so far.
The particle accelerator, which has a circumference of 27km, is buried 100 metres below the mountains on the Swiss-French border.
After three hours of stable beams and proton-proton collisions today, an update from CERN on Twitter reported that physicists had observed more than 500,000 events collision fragments in the data captured at 7TeV. Data from the collisions are expected to begin flowing tonight from the LHC to collaborating centres across the world.
It might take six months before we can discuss concrete results, said Atul Gurtu, a physicist at the Tata Institute of Fundamental Research, Mumbai. The LHC is now expected to run for about 18 months before it goes into a long shutdown and an upgrade to achieve the 14TeV target, Gurtu said.
Scientists circulated the first protons in the LHC in September 2008, but a cooling failure led to a shutdown until November 2009 when low-energy proton-proton collisions were achieved. On March 19 this year, the energy of each beam was ramped up to 3.5TeV without collisions.
The LHC beam operations demand a temperature just a whisker above absolute zero. The first attempt to ramp up the beam energy this morning failed with another cooling system crash.
But the system was recovered over a period of about two hours. The machine made us tremble and shiver this morning but weve made it. We now have perfect collisions, said a physicist observing this mornings developments at the LHC.