Ciclo di Conferenze dei corsi di Laurea in Fisica e del Dipartimento di Matematica e Fisica
Comitato organizzatore: D. Meloni, F. La Franca, L. Lupi, S. Lauro, S. Mari, F. Paolucci
Edizione 2025
Fabio Finocchi
Institut des NanoSciences de Paris (INSP), CNRS and Sorbonne University
Nuclear quantum effects in condensed matter
Link identifier #identifier__118612-1Locandina – 4 febbraio 2025 – ore 14:30 Aula A
It becomes nowadays possible to conceive and design materials with specific properties, almost from scratch. Matter consists of an assembly of electrons and nuclei. Although much heavier than electrons, light nuclei, mainly hydrogen, exhibit quantization of the vibrational levels, zero-point energy and tunnelling. These so-called Nuclear Quantum Effects (NQE) can have a large impact on the structure and the dynamics of materials. NQE are also crucial for describing heavier nuclei at low temperatures and other phenomena, such as isotope effects, that escape a purely classical frame.
The behaviour of systems that are at the borderline between the classical and quantum worlds is in general complex. The genuine quantum characteristics might be spoiled by electric fields, high disorder, etc. I will illustrate through selected examples some paradoxical effects that can be encountered in condensed matter : ice and exotic phases of methane hydrates at extreme pressures, typical of those inside giant icy planets of the solar system. I will also show the spectacular isotope effects in the phase transition of Sodium Hydroxide, which has hindered its explanation for about 40 years. I will conclude by discussing the importance of simulation methods that are able to account for the quantum dynamics of nuclei. In the last decade, in our group we have developed numerical models and theories that account for nuclear quantum effects, at various approximation levels. for instance in the semi-classical regime, in the framework of the generalized Langevin equation.
The advent of machine-learning based techniques has opened the way to refine models for describing the inter-atomic forces, and the nuclear quantum effects, even if modest, might change the statistical properties appreciably.
Their explicit inclusion in simulations is an emerging field of research, with impact on many fields, spanning materials science, geophysics, physical chemistry and biochemistry
Luigi Coraggio
Dipartimento di Matematica e Fisica dell’Università degli Studi della Campania “Luigi Vanvitelli”, e Sezione INFN di Napoli
A historical journey: 90 years of the evolution of our knowledge of the nuclear interaction
Link identifier #identifier__148748-2Locandina – 21 febbraio 2025 ore 14:30 Aula M6
Historically, the first attempt to develop a fundamental theory of nuclear forces was carried out by the Japanese physicist Hideki Yukawa in 1935, who proposed that the force among nucleons would explicate through the exchange of mesons. This meson theory has been the most popular approach to nuclear forces for more than half a century, and also the cornerstone of modern approaches that are grounded on the effective field theory (EFT) in order to match the fundamental theory of strong interactions – the quantum chromodynamics (QCD) – and the physics of low-energy nuclear systems. I will review the history of the development our understanding of the nuclear potential, and present modern ideas which apply the concept of an effective field theory to low-energy QCD, as well as our present knowledge of the interaction among nucleons as also allowed the advance of microscopic calculations of the properties of many-nucleon systems.
The contents of my presentation are aimed to an audience of non-experts in nuclear-physics problems, in particular to graduate students.
Tommaso Chiarusi
INFN Sezione di Bologna
High energy neutrino telescopes: under ice and under water challenges and new findings
Link identifier #identifier__37110-3Locandina – 13 marzo ore 14:30 Aula G
Neutrino astronomy has acquired an increasingly important role in investigating violent phenomena in remote regions of the universe, completing the multi-messenger scenario together with electromagnetic radiation, cosmic rays and gravitational waves.
The flux of astrophysical neutrinos, in the energy region of greatest interest, i.e. above 100 TeV, is rather small and it drives the construction of cubic-kilometre scale detectors which must operate for decades.This is the target for the second generation of underwater and under-ice Cherenkov neutrino telescopes, namely IceCube, KM3NeT and GVD-Baikal. IceCube has already reached an instrumented volume of about 1 km3, while KM3NeT and GVD-Baikal will reach the target in the coming years. This contribution will review the scope and the main characteristics of such detectors, discussing their similarities and differences in terms of construction and performance. A review of the main recent scientific findings will also be given, with emphasis to the ultra high energetic neutrino discovered by KM3NeT and published in Nature last February 12th 2025. Finally, the role of these experiments in the context of Global Neutrino Network will be discussed, along with new projects that are still in the design phase or are testing the first detector prototypes.
Cristiano De Michele
Sapienza Università di Roma
Extremely Coarse-Grained modeling of Multimeric G Quadruplexes
16 aprile ore 14:30 Aula B
Biological macromolecules, such as DNA duplexes, proteins and polypeptides, comprise many degree of freedom and live in a water environment. Numerical methods have been widely used to study these biological systems, but many of these methods, such as atomistic molecular dynamics , are rather demanding if many or very large biomolecules are considered. To overcome these limitations, extremely coarse-grained models can be employed, where within these approaches biomolecules retain few degrees of freedom and water is treated implicitly, thus making simulations feasible. A prominent example is provided by G-quadruplexes (G4s), which are helical four-stranded structures forming from guanine-rich nucleic acid sequences and which are thought to play a role in cancer development and malignant transformation. In this seminar I will show examples of extremely coarse-grained modeling of some biomolecules with special focus on telomeric G4 multimers. Concerning G4s, I will present a novel low-resolution structural approach that combines small-angle X-ray scattering (SAXS) with extremely coarse-grained (ECG) simulations and that allows us to quantify physical properties of these systems. Complexation of G4 with benchmark ligands, i.e. possible anti-cancer drugs, has been also studied through this approach, proving that it can be an affordable tool aiding in the selection and design of drugs that target G4s under physiological conditions.
Prossimi colloqui
26 maggio – Riccardo Torre
INFN di Genova
25 giugno – Riccardo Claudi “The search for life: an astrophysicist’s point of view”
INAF – Istituto di Astrofisica e Planetologia Spaziali
luglio – Manuela Magliocchetti (data da definire)
INAF – Istituto di Astrofisica e Planetologia Spaziali
11 settembre – Claudia Hagedorn
IFIC di Valencia
21 ottobre – Carmine Ortix
Università di Salerno
4 novembre – Gianmaria Sannino
Enea