Invited Seminars

IIHE invited seminar: The PTOLEMY project: from an idea to a real experiment to detect the Cosmological Relic Neutrinos

by Prof. Marcello Messina (LNGS)

G/0-G.0.20 - Neutrino Room (Building G)

G/0-G.0.20 - Neutrino Room

Building G


In the first part the seminar a novel idea on the detection of Cosmological Relic Neutrinos (CRN) and more in
general, on the detection of neutrinos of vanishing energy will be presented. This idea is described in detail in the
paper [1]. The method is based on the fact that neutrino interactions on beta-instable nuclei have the key feature of
requiring no energy threshold for the neutrino interaction. Some phenomenological aspects will be presented.
The second part of the seminar will be dedicated to the PTOLEMY project, in a starting phase at the Laboratori
Nazionali del Gran Sasso, Italy. In this project we aim at demonstrating the detection principle of the CRN and
finalize the design of the future full scale experiment. The technologies on which the detector concept is based will
be presented and the key features explained.
A new-concept of electrostatic filter discussed in a paper [2] recently published by the PTOLEMY collaboration will
also be explained in details.
[1] A. Cocco, G. Mangano and M. Messina, “Probing Low Energy Neutrino Backgrounds with Neutrino Capture on
Beta Decaying Nuclei,”
Journal of Cosmological and Astroparticle Physics 0706 (2007), 15.
[2] M.G. Betti et al, “A Design for an electromagnetic filter for precision energy measurements at tritium endpoint”,
Progress in particle and Nuclear Physics, 1206 (2019), 120.



Short bio:  Dr, Messina got the Master degree and then the Ph.D. on the CHORUS experiment on the numu to nutau oscillation searches. After Ph.D. he moved to the ETH-Zurich on a research position and then to the University of Bern as Ober Assistant. In these years he participated to several important experiments like OPERA, ICARUS, T2K with relevant coordination roles of R&Ds activities and working groups. In 2011 he moved to the Columbia University in New York on a position of Research Scientist and lead the  R&D effort that brought to design of the XENON1T detector. In the same experiment he has been first the Commissioning and then the Operation manager of the Experiment until 2017 when he moved on the role of Technical Coordinator of the XENONnT experiment, which is the upgrade of the XENON1T. After the seminal paper [1] on the relic neutrino detection his interests switched towards  relic neutrino detection up to the participatation to the conceptual design of a novel electromagnetic filter concept. Dr. Messina is presently  the Co-Spokespersons of the PTOLEMY project.

Organized by

Ioana Maris and Steven Lowette