Physics

Dr. Arijit Sharma
Helmholtz Institut Mainz, Germany

Abstract : 

Studies of rotation curves of galaxies, initiated by Oort & Zwicky (1930s) and later by Rubin (1970s) led to the Dark Matter (DM) hypothesis and the subsequent evidence for the existence of Dark Matter and dark energy. Search for the elusive dark matter candidates has been going on since the early 1970s. Oddly the Standard Model (SM) with all its tremendous successes (most notably, in the recent past, being the discovery of the Higgs boson at the LHC, CERN) has so far failed to provide an insight into the candidates that may directly or indirectly relate to Dark Matter. Experimental efforts have also been initiated for searches of WIMPs (Weakly Interacting Massive Particles), who are potential Dark Matter candidates, with the recent results published from the XENON1T and PANDAX-II (Ref: PRL 119, 181301 (2017) & PRL 119, 181302 (2017) respectively). However, these two experimental searches including the ones at the LHC, CERN have still not produced any definitive outcome for the elusive Dark Matter particles. In our group, we are trying to search for possible Dark Matter (DM) candidates through precision atomic spectroscopy on dysprosium (Dy) atoms. The idea is based on isotope shifts spectroscopy (ISS) and establishing a King Plot (KP) through frequency measurements across multiple isotopes of Dy in the RF (Radio Frequency) and the optical domain. In an ideal scenario, the King Plot (KP) is linear with mass and frequency ratio scaling measured for two different transitions across multiple isotopes. Non-linearities in the King Plot may arise from possible dark matter candidates that couple to the atomic nucleus and electrons through short range forces. I shall present our experimental efforts that have been initiated towards this end with an emphasis on the current status and possible experimental outcomes.