Grant: Discovery Grants Program - Individual

To further support ongoing theoretical and computational experimental research in which I am involved, this proposal describes methods to understand polar molecules (such as BaF=barium monofluoride) trapped in a frozen rare-gas matrix. This is a new area of research that I have engaged in in the past two years as part of a theoretical/experimental collaboration.This is pursued for fundamental particle physics purposes, but the anticipated results can be used by other laboratory scientists in the field of precision measurements and chemical physics. The frozen rare-gas matrix environment allows to store large samples of molecules which are free of rotational motion. The effect of the matrix on these molecules needs to be studied carefully, and first results from BaF in Ne are very encouraging. The development of the methodology will be of interest to other settings, such as pharmaceutical research with potential benefits in the public sector. Further proposed research concerns a continuation of previous work on collisions of ions with molecules of biomedical interest, starting with water, but extending to biomolecules such as DNA and RNA. The York group has made significant progress both using a novel independent-atom model approach where precise ion-atom collision data are combined to obtain results for ion-molecule collisions. In addition the group has modelled detailed ionized electron data using a new classical trajectory model. This work is of interest to medical researchers who use such data to model the desired radiation damage of cancer cells in proton beam and ion beam therapy. To complement this work we are studying the ionization behaviour of small molecules such as water, ammonia, methane and other carbohydrates under the influence of strong electric fields fields. This shall lead to a better understanding of the possibilities for laser radiation therapy and other applications. To summarize the main new focus of this work described in the first paragraph above, and why it is of substantial interest across disciplines, from atomic/molecular to particle physics we can state the following: the study of polar molecules, such as barium monofluoride (BaF), is relevant for a topic in fundamental particle physics, namely the determination of the electron electric dipole moment (eEDM). This quantity provides strong tests of physical theories beyond the standard model. Results obtained in beams of polar molecules have already ruled out classes of so-called supersymmetric models which predict a large eEDM value. The sensitivity of these molecular beam experiments can be improved by many orders of magnitude when trapping a large quantity of molecules in a rare-gas matrix. This is fundamental research at the frontier of particle physics which over the course of the next decade should yield a better understanding of the nature of the electron.