The IPA Rahul Basu Memorial Awards for the best theses in High Energy Physics 2020, were presented on 18th December 2020 in a virtual ceremony hosted at the DAE symposium at NISER Bhubaneshwar. While the virtual nature of the ceremony was inevitable due to the current pandemic, it is interesting to note that virtual presentations have been a feature of the award ceremony right since its first edition in 2012, as befits an award for a community which invented the internet.
The winners of the award, as announced earlier, were Dr. Resmi P K, Indian Institute of Technology Madras, for her thesis on the ` Measurement of the CKM angle ð_3 from ðĩ± →
ð·(K_s0 pi+pi-pi0)ðū± decays and future prospects, and Dr. Manibrata Sen, Tata Institute of Fundamental Research, Mumbai for his thesis on ` New aspects of supernova neutrino flavour conversions: In the standard model and beyond'.
The awardees presented their work in very clear talks which conveyed the flavour of their work to the large, if virtual, audience. Dr. P.K. Resmi had carried out a very careful analysis of the quantum correlated DDbar data collected at CLEO-c to measure the charge-parity content of the decay D decaying to K_s0, pi+, Pi- and pi0, and measure the strong phase difference of the decay. This was a difficult problem, and required very skilful analysis of experimental data and the understanding of detector effects. Her thesis also contained a proof of principle of the determination of gamma using data from the Belle experiment using her earlier results. This analysis was the first of its kind, and was one of the determing factors which fetched her the award.
The other awardee, Dr Manibrata Sen, had explored the nonlinear collective neutrino oscillations of supernova neutrinos. His focus was on the newly discovered phenomenon of “fast flavor conversions” that start taking place as deep as at a radius of about 10 km from the centre of the exploding star, when certain symmetries are broken. Neutrino-neutrino interactions inside a supernova core yield nonlinear equations for neutrino flavour evolution. These collective oscillations and their effects on emitted neutrino spectra,
were studied via a mathematical model of neutrinos and antineutrinos, and the oscillations of a particle in a quartic potential. This provided an analytical understanding of the neutrino flavor dynamics in the fully non-linear regime for the first time, and was supplemented by a numerical study.
Due to the large number of excellent nominations received, in addition to the winners, the award committee chose three recipients for honorable mentions. These were, Dr. Chandrodoy Chattopadhyay, Tata Institute of Fundamental Research, Mumbai for the thesis `Entropy production and thermal fluctuations in higher- order dissipative hydrodynamics,' Dr. Rafiqul Rahaman, Indian Institute of Science Education and Research, Kolkata, for his thesis on the `Study of anomalous gauge boson self-couplings and the role of spin-1 polarizations', and Dr. Suman Chatterjee, Tata Institute of Fundamental Research, Mumbai, for his thesis entitled `Jets as probes for precision measurements and candles for physics beyond the standard model'.
The thesis of Dr. Chandroday Chattopadhyay contained contributed interesting new directions in the use of relativistic dissipative hydrodynamics for probing the properties of the strongly interacting Quark-Gluon Plasma (QGP) formed at RHIC and LHC energies. His thesis demonstrated a set of initial conditions which when used with transport and hydrodynamic models provided good agreement with experimental data. His work also explored the properties of hydrodyanamic attractors for systems far from equilibrium.
Dr. Suman Chatterjee had studied the differential measurements of different-radii jets in QCD multijet events at the LHC. He developed data-driven techniques to cope with the overwhelming standard model backgrounds, namely the QCD-multijet production, and the top quark-antiquark pair production.
Dr. Rafiqul Rahaman had worked on the usage of polarisations of W/Z bosons to probe possible new physics in the processes involving these particles at the ILC and LHC. His analysis identified the complete set of polarizations required for this analysis in terms of spin/polarization density matrices. This was used to analyse anomalous triple gauge boson couplings in the neutral sector at ILC through the ZZ and Z-gamma production processes. He also studied W+W- production at ILC and the ZZ and WZ processes at the LHC in the context of anomalous triple gauge couplings.
The award ceremony held at the DAE symposium at NISER, Bhubaneshwar, was very well attended in the online mode. Prof. Rohini Godbole chaired the session, and Prof. Bedanga Mohanty conducted the talks. The winners were given a cash prize of Rs.25,000/- each and a citation and the runners up received citations.
Our grateful thanks to the Indian Physics Association for the administration of this award. The award committee consisted of Profs. Bedangadas Mohanty, Sunanda Bannerjee, Debashis Ghoshal, Sourendu Gupta, Rohini Godbole, Jim Libby, Sunil Mukhi and Seema Sharma. They put in herculaean efforts in sifting through the huge number of really excellent nominations to identify the winners in the short span of time available. This was fifth edition of the award. We are really happy to see the enthusiasm and competition it has generated in this span in young high energy physicists. We look forward to even more intense competition in future editions.
This blog post is by Neelima Gupte and Sumathi Rao.
