The research activity of the group lies within the scope of particle physics, with two experimental areas.

The g-2 experiment is meant to measure the anomalous magnetic moment of the muon, with such an accuracy as to be able to confirm or refute a probable discrepancy with theoretical predictions. The experimental measurement and the predictions of the Standard Model (SM) diverge for 3.3-3.6 standard deviations, and many extensions of the SM, e.g., the supersymmetries, could cause this effect. The expected four-fold improvement (0.14 ppm) in experimental precision, with reference to the previous experiment, could establish beyond any doubt a signal of new physics.

The activities performed in this area are aimed at planning and building a calibration and monitoring system for the photodetectors (silicon photomultipliers or SiPM) of the electromagnetic calorimeters of the experimental device. The calibration system employs a laser light source as a common reference point, periodically illuminating the approximately 1,300 crystals of the calorimeter. The laser light is measured by SiPMs, just like the Cherenkov light caused by the absorption of the positrons produced by the decay of the muons. It is expected that the light pulses from the common source will provide a reliable calibration of the time of detection, and improve the comparison of the energy deposited by the same particles onto different crystals, so that the measure of the positrons' energy can be calibrated. The laser calibration system will monitor the intensity of the common light source and the stability of the system distributing light to the crystals, which can be affected by fluctuations in the laser beam aiming, by mechanical vibrations or by the ageing of transmission elements.

The FAMU experiment (Physics, Muonic Atoms) will perform the first measurement of the hyperfine splitting (hfs) in the 1S state of muonic hydrogen – thus providing key information about the structure of the proton and about the muon-nucleon interaction. By using an intense, pulsed muon beam and a high-energy mid-infrared laser that is being developed in the framework of the experiment through a collaboration with Elettra Sincrotrone Trieste, FAMU represents a meaningful advance in the quality of spectroscopy experiments with muonic atoms. In particular, the experiment will allow the measurement of the rZ parameter, linked with the radius of the proton, called "proton Zemach radius rZ " with a higher accuracy than what has been possible until now. This will allow the choice among differing theoretical predictions and the quantification of any plausible difference among rZ values as extracted through measurements on normal atoms or through measurements on muonic atoms. This experiment is meant to shed light on anomalies that still remain unexplained as to the proton Rch charge radius (proton radius puzzle).

An intense, pulsed beam of protons enters and stops in the gaseous hydrogen target, forming hydrogen muonic atoms. The hfs resonance frequency will be accurately measured through the comparison of the distribution of events achieved by the transfer of the muon from hydrogen to a heavier gas atom, added to hydrogen, in the two conditions: with or without laser pulse excitation. A high-reflectivity cavity inserted in the target will amplify the laser pulse effect. The theoretical and experimental effort of this experiment will establish new limits as to the parameters of the structure of the proton by measuring the transition, and will supply new data as to the relationship of magnetic and charge form factors of the proton having a low transferred moment.