At CERN, Indian Physicist Archana Sharma Seeks Answers To Universe's Greatest Secret

New Delhi: After helping find the 'God Particle', India's Dr Archana Sharma and teams at CERN in Geneva will now look for Dark Matter, hoping to unravel the deepest hidden secret of the Universe. More than a decade after the discovery of the Higgs boson, popularly known as the God Particle, scientists at the world's largest experimental facility named European Centre for Nuclear Research (CERN) are preparing for what could become an even bigger scientific breakthrough: uncovering the nature of Dark Matter and perhaps shedding light on Dark Energy, the mysterious entities that together account for about 95 per cent of the Universe.The quest is being led by thousands of scientists from around the world; among them is Indian scientist Dr Archana Sharma, a senior CERN physicist who has been closely associated with some of the laboratory's most important experiments.Speaking to NDTV, Dr Sharma highlighted a sobering reality. Despite all the advances in modern science, humanity understands only a tiny fraction of the cosmos."What we see is about 5 per cent," she said. That means almost 95 per cent of the universe remains unexplained. "We do not know which part is Dark Energy and which is Dark Matter."The challenge facing physicists today is therefore far greater than the one that led to the discovery of the Higgs-Boson in 2012. While the Higgs completed the Standard Model of particle physics, Dark Matter and Dark Energy lie completely outside humanity's current understanding of nature.CERN is home to the Large Hadron Collider (LHC), the world's largest and most powerful particle accelerator. The giant machine sits in a circular tunnel about 27 kilometres in circumference straddling the Swiss-French border. Built at a cost of several billion dollars through international collaboration, the LHC accelerates particles to near the speed of light and smashes them together, recreating conditions that existed fractions of a second after the birth of the universe.Its greatest triumph came in 2012 when scientists announced the discovery of the Higgs Boson or the 'God Particle', confirming a crucial missing piece of modern physics. The achievement earned the 2013 Nobel Prize in Physics for theorists Peter Higgs and Francois Englert.Now CERN is embarking on a new chapter. The LHC is undergoing a major upgrade to become the High Luminosity Large Hadron Collider, or HL-LHC. This upgraded machine is expected to dramatically increase the number of particle collisions and the amount of data available to scientists.Dr Sharma explained that the transformation is enormous in scale. "We will upgrade our machine, we'll upgrade the detectors, we'll upgrade software so that we are able to cope with what's coming next," she said."It will see 10 times the collision rates of what we have seen previously. It means that in one year we will be able to collect the data that we could collect in 10 years before."The vast increase in data is critical because if Dark Matter particles are being produced in particle collisions, the signals are expected to be extremely rare and difficult to identify.Dark matter itself remains one of science's greatest mysteries. Astronomers cannot see it directly because it does not emit, absorb or reflect light. Yet its gravitational influence is visible across the universe.Scientists know something unseen is present because galaxies rotate faster than they should if only visible matter existed. Massive clusters of galaxies also contain far more gravitational pull than can be explained by stars, planets and gas alone. Observations of the evolution of the universe further reinforce the conclusion that an invisible form of matter must exist.A simple analogy offered by Dr Sharma helps explain the idea. If a magnet is hidden beneath a table, metal objects placed on top will move in unexpected ways. Even without seeing the magnet, one can infer its existence from its effects. Similarly, scientists infer the existence of dark matter from the way gravity shapes galaxies and the large-scale structure of the universe.Dark Energy is even more mysterious. It is believed to be responsible for the accelerating expansion of the universe, pushing galaxies apart at increasing speeds. While it appears to make up most of the cosmos, scientists still do not know what it actually is.The upgraded collider may not directly discover Dark Energy, but it could uncover new particles or new physics that point toward answers.CERN researchers are already finding intriguing clues. According to Dr Sharma, experiments have recently identified exotic composite particles made from heavier quarks. These include unusual combinations of quarks that expand scientist's understanding of how matter can be assembled.However, she cautioned that these newly observed particles are not Dark Matter. "If Dark Matter was made out of 'matter' particles then yes, but we know that Dark Matter is not made out of 'matter' particles and what we have seen are matter particles," she said."So there's something, another kind of species out there which we do not understand and we might be looking at hints in the High Luminosity LHC."That possibility is what excites physicists across the globe. Finding Dark Matter would transform humanity's understanding of the universe. It would reveal the nature of the invisible substance that outweighs ordinary matter by many times and dominates the cosmic structure. Such a discovery would rank alongside the greatest scientific achievements in history.For Dr Sharma, who was part of the CERN era that delivered the Higgs-Boson, the search now moves into even deeper territory? "We understand very little," she said. "We understand only a few per cent of what the universe is."As the upgraded collider prepares to begin its next phase, scientists hope that the machine which helped reveal the 'God Particle' may now illuminate the much larger hidden universe that has remained beyond humanity's reach. The holy grail of modern physics is no longer the 5 per cent we know. It is the mysterious 95 per cent that remains in the dark.