Speaker
Description
The PADME experiment (Positron Annihilation into Dark Matter Experiment), at the Laboratori Nazionali di Frascati
Beam Test Facility,
is designed to search for light dark sector particles in positron-on-target interactions.
Among its physics goals is the investigation of anomalies in leptonic final states, such as the excess in the
e+e− → e+e− channel seen in the data collected in the fall of 2022 at an invariant mass of about 17 MeV/c^2.
A new data-taking campaign has been carried out between June and October 2025, whose major upgrade consisted in the installation
of a tracking detector based on Micromegas technology, aiming to significantly improve neutral background rejection.
The detector consists of a resistive Micromegas chamber with two 5 cm drift regions separated by a floating mesh acting as
a cathode, and two-dimensional readout planes with a strip pitch of 1.2 mm. The enlarged drift gap allows the detector to be operated as
a Time Projection Chamber (TPC). Precise timing information and high granularity of the readout allow the reconstruction
of particle tracks in three dimensions. Given the large drift distance, a fast gas mixture Ar:CF4:iC4H10 = 88:10:2 has been adopted.
The detector geometry is optimised to provide high spatial resolution in track reconstruction without the need
for a multi-layer tracking system, reducing the material budget. Furthermore, the detector has been designed to be able to monitor
the positron beam position as well as the number of positrons during the data taking.
The construction of the detector, the results of validation studies with cosmic rays prior to installation, and the preliminary
results on its performances obtained during the commissioning of the experiment are presented.
| Name of the speaker | Not Known |
|---|---|
| Eligible for the Georges Charpak Young Scientist Award. | no |