The High Energy Accelerator Research Organisation (KEK) completed the much-awaited ‘rolling-in’ of the Belle-II experiment in Tsukuba, Japan, today. This experiment is designed to study violations of the Standard Model and dark matter. A grand collaboration of 700 scientists from 23 countries, Belle-II has a significant Indian participation both on experimental and theoretical sides. The fourth layer of the six-layer, highly sensitive particle detector, which is at the heart of Belle-II, has been built by Indian scientists, led by Tariq Aziz and Gagan Mohanty, who are with the Tata Institute of Fundamental Research (TIFR), Mumbai. “In 1998, when Indians [in this field] were working mostly with CERN (European Organisation for Nuclear Research), KEK first wanted us to participate in this experiment, which had a complementary approach,” says Prof Aziz.
Belle-II has better sensitivity, some 50 times higher, than its predecessor, Belle. “Initially, we did not have the chance to build the detector, and this is the second step — to work with the inner part of the detector, where the resolution has to be high. We are happy we did it and are now among four important groups in the world that can build such detectors,” Professor Aziz says.
Scientists from the Indian Institutes of Technology (IITs) in Bhubaneswar, Chennai, Guwahati and Hyderabad; the Institute of Mathematical Sciences (IMSc), Chennai; Punjab University; Punjab Agricultural University; MNIT (Malaviya National Institute of Technology), Jaipur; IISER (Indian Institutes of Science Education and Research) Mohali; and TIFR, Mumbai, are participating in this research. “Building the silicon vertex detector has been a directing force that brought us together. It is a very young team, with an average age of 30 years, apart from some senior leaders,” says Professor Mohanty.
The lone person leading theoretical studies among this group of 35-40 experimentalists, IMSc’s Rahul Sinha says, “Some of the modes and techniques that will be possible for Belle-II to study were first proposed by the group at IMSc.”
Complementary to the direct search experiments being carried out at the Large Hadron Collider in CERN, Belle-II will indirectly probe new physics using intense electron-positron beams and a sensitive detector. Indian scientists led by TIFR have built a part of the highly sensitive silicon vertex detector, which will be attached to the set up at a later date, now that the rest have been successfully integrated. The silicon vertex detector has a six-layered structure and the fourth layer was constructed by Indian scientists.
