Silviu Udresu

Precision spectroscopy studies of radioactive molecules for fundamental physics

Abstract:

Molecules are unique quantum systems for fundamental physics studies. Possessing a large sensitivity to nuclear effects and violations of the fundamental symmetries of nature, they can enable precision tests of the Standard Model and the possibility to probe energy scales beyond tens of TeV. Molecules containing octupole-deformed nuclei, such as radium monofluoride (RaF), are expected to be particularly sensitive to symmetry violating nuclear properties. In this talk, I will present the results obtained from a series of laser spectroscopy experiments performed on short-lived RaF molecules at the ISOLDE facility at CERN. The vibrational structure of (223-226,228)RaF and the rotational and hyperfine structure of 226RaF and 225RaF were measured with high precision. This allowed us to establish a laser cooling scheme for these molecules and to investigate the effects of electroweak nuclear properties on the molecular energy levels. These results are the first of their kind performed on radioactive, short-lived molecules, opening the way for future precision studies and new physics searches in these systems. I will then discuss the current status of a novel experiment aiming to measure hadronic parity violation using molecular ions inside a Penning trap. Our method should allow measurements over the entire nuclear chart, providing enhancements in the sensitivity to the sought for signals of more than 12 orders of magnitude compared to atoms. Finally, I will present the developments of a highly sensitive experimental setup for precision laser spectroscopy studies of very short-lived isotopes (lifetime < 1 ms), produced in small amounts (< 1/minute) in hot environments, without the need for cooling techniques. Such nuclear systems are of paramount importance to guide our understanding of nuclear matter and connect our description of nuclei with the underlying theory of the strong force.