Friday, December 26, 2014

The IPA Rahul Basu Memorial Award

The IPA Rahul Basu Memorial Award  (2014) for the best thesis in High Energy Physics was presented on 12th December, 2014, at the DAE Symposium held at IIT Guwahati. As mentioned in one of the earlier posts, the two awardees for the 2012-2014 period were Dr. Pratishruti Saha (Univ. of Delhi) for her thesis entitled `Addressing some issues beyond the standard model at Hadron Colliders', and Dr.  Nikhil Karthik (TIFR, Mumbai) for his thesis entitled `Studies on gauge link smearing and their applications to lattice QCD at finite temperature', and two  honourable mentions, Dr.  Ritu Aggarwal (Panjab University) for her thesis entitled `Measurement of High x neutral current ep cross sections and extraction of xF3 structure function using Zeus detector at Hera', and Dr.  Amaresh Jaiswal (TIFR, Mumbai) for his thesis entitled `Formulation of relativistic dissipative fluid dynamics and its applications in heavy-ion collisions'.  The two awardees gave talks on their work during the award ceremony, Dr. Saha, in person, and Dr. Karthik via a Skype connection.

Dr. Saha explained how her work on  direct and indirect searches at various accelerators could be used to identify new physics.  A very well cited paper of her's identifies  how measurements at the Tevatron and the LHC could be used to distinguish between various scenarios which go beyond the Standard Model. Dr. Saha and co-workers had  considered how top polarisation could be used to distinguish between various scenarios, which had been used to explain asymmetries in the top quark production process. The work also had relevance to observations at the Large Hadron Collider.  Her thesis focused on the fact that the top quark occupies a special place in the standard model, and hence, the analysis of its behaviour can have important implications in scenarios which attempt to go beyond the Standard model, in various sectors like the Higgs sector.  She had also analysed the behaviour of the bottom quark and its contribution to resonances.

Dr. Nikhil Karthik spoke about the work in his thesis, which contributes to important technical advances in  lattice QCD, and also studies its deconfined phase. Although the coupling constant in this  phase is not too large, perturbative estimates of quantities like the viscosity and the screening mass do not agree with expectations due to discretization effects. Specifically, existing lattice studies based on the staggered discretization of quarks, found a screening mass which, contrary to expectations is smaller than that of the free field theory. Smoothed gauge configurations are the prescription to ameliorate such unwanted discretization effects. Dr. Karthik's thesis investigated the effects of different types of smoothing, and devised an optimum smoothing strategy which succeeded in   identifying the reasons why the screening mass shows the observed behaviour.  Dr. Karthik's talk was also notable due to the clarity with which technical issues were conveyed to the audience.

The award ceremony was well attended, with many students and many well known physicists in the audience. It was heartwarming that three of these were  Rahul's friends in graduate school,  Prof. Rohini Godbole, Prof. Ashoke Sen, and Prof. Sunil Mukhi, distinguished physicists, and in the case of Profs. Mukhi and Godbole, members of the award committee. We congratulate the winners, and wish them all success in their future endeavours.

This blog post is by Neelima  Gupte and Sumathi Rao.