The search for Dark Matter (DM), has resulted in an intensive experimental study effort over the last few decades, during which a great deal of effort has been expended in the search for Weakly Interacting Massive Particles (WIMPs) with masses ranging from GeV to 100 TeV. Despite that, unambiguous results are still missing.
The reason is to be found in the elusiveness of such particles. The estimated cross section for a DM-nucleus interaction is of the order of 10-26 events/s. It is therefore necessary to use systems containing Avogadro’s number of atoms to obtain a sizable event rate: condensed matter systems are an excellent detection tool, however, even in this case, just approximately 1 event per year is expected.
Many different ways to calculate the DM detection rate have been proposed. Assuming spin-independent DM-electron interaction Hamiltonian, we can compute the expression of the DM scattering rate directly in terms of the energy loss function, given by the inverse of the dielectric constant of the material under consideration. The dielectric constant can be calculated by first-principle methods based on the Density Functional Theory. The calculations are completely free of empirical or semi-empirical parameters and represents the state of the art for the description of excitation in solid and molecular systems, ranging from insulators, semiconductors, semi-metals and metals.
Another Effective Field Theory has been developed to expand the prediction of sub-GeV DM-electron excitation, both q- and spin-dependent, depending on the non-relativistic calculation of the electron ionization rate.
Thus, the goal of the project is to develop an operational methodology to deal with the scattering rate calculation of a given system, with the aim to predict new and promising materials for the detection.
Duration of stay: 1st March to 30th April 2023
|Cesare Tresca||Consiglio Nazionale delle Ricerche - SuPerconducting and other INnovative materials and devices institute|