Tag Archives: Evento scientifico

Speaker: Agostino Marinelli (SLAC National Accelerator Laboratory) Attosecond XFELs are the subject of an intense research program at LCLS and other laboratories worldwide. I will discuss recent advances in the field: from the extension of attosecond science to high-repetition rate XFELs, to the demonstration of attosecond hard x-ray pulses using amplified stimulated emission in atomic lasers.

Speaker: Gino Isidori (University of Zurich) What is the origin of the different masses for quarks and leptons is one of the big open questions in particle physics. I will briefly review this problem, illustrating its central role in achieving a deeper understanding of fundamental interactions. I will also outline some recent theoretical ideas on how to address it, focusing in particular on the concept of “flavor deconstruction”, and finally discuss how these ideas can be tested through current and future flavor-physics experiments.

Accelerator-based particle physics research is entering a momentous phase. The update of the European Strategy for Particle Physics is now under way, with the goal of submitting the community recommendation for the next flagship project to the CERN Council next year. Several different projects are currently under evaluation. Moreover, next year the LHC will enter its third long shutdown in order to be upgraded to the HL-LHC. In this mini-workshop we will focus first on the FCC-ee, and then more broadly on the role of the upcoming precision physics program. The first presentation will be from Frank Zimmermann and Michael Benedikt from CERN, who will discuss the technical aspects related to the construction of the FCC-ee collider. The second contribution will be from Pier Monni, also from CERN, who will discuss the role (and the challenges) of the precision physics program at the FCC, as well as at the HL-LHC. If you are coming from outside LNF, please register so that we can arrange permission for you to enter the campus. Contacts: Manuela Boscolo (manuela.boscolo@lnf.infn.it) and Emanuele Bagnaschi (emanuele.angelo.bagnaschi@lnf.infn.it) Secretariat: M. Legramante (maddalena.legramante@lnf.infn.it)  

Speaker: Elisabetta Manca (UCLA) The W boson mass is measured using proton-proton collision data at corresponding to an integrated luminosity of 16.8 inverse fb recorded during 2016 by the CMS experiment. The W boson mass is obtained from a fit of the two dimensional pT-η distribution in a sample of W→μν decays, categorized by charge, yielding one of the most precise measurements of the W mass to date.

Speaker: Lorenzo Calibbi (Nankai University) I will present a recent work where we assessed the capability of Gravitational Wave (GW) experiments to probe the origin of the flavour sector of the Standard Model. Within the context of the Froggatt-Nielsen mechanism to generate the hierarchical patterns of fermion masses and mixing based on a gauged U(1) flavour symmetry, we investigated the formation of cosmic strings and the resulting GW background (GWB), estimating the sensitivity to the model’s parameter space of future GW observatories. Comparing these results with the bounds from low-energy flavour observables, we found that these two types of experimental probes of the model are nicely complementary. In certain scenarios, the combination of flavour constraints and future GW bounds can bring about a complete closure of the parameter space, which (once again) illustrates the potential of GWB searches to test fundamental interactions at ultra-high energy scales beyond the reach of laboratory experiments.

Speaker: Gianluca Cavoto (Istituto Nazionale di Fisica Nucleare) The observation of a resonance structure in the opening angle of the electron-positron pairs in the 7Li(p,e+e−)8Be reaction was claimed and interpreted as the production and subsequent decay of a hypothetical particle (X17). Similar excesses, consistent with this particle, were later observed in processes involving 4He and 12C nuclei with the same experimental technique. The MEG-II apparatus at PSI, designed to search for the µ+ → e+ γ decay, can be exploited to investigate the existence of this particle and study its nature. Protons from a Cockroft-Walton accelerator, with an energy up to 1.1 MeV, were delivered on a dedicated Li-based target. The γ and the e+ e− pair emerging from the 8Be transitions were studied with calorimeters and a spectrometer, featuring a broader angular acceptance than previous experiments. In this seminar we present the analysis and the result of a four-week data-taking in 2023 with proton energy varying from 400 keV to 1080 keV, resulting in the excitation of two different resonances with Q-value 17.6 MeV and 18.1 MeV.

Speaker: Sven Heinemeyer (IFCA (CSIC, Santander)) The baryon asymmetry of the universe naturally leads to BSM Higgs sectors. Such models contain additional Higgs bosons w.r.t. the SM Higgs boson, leading to a Higgs potential substantially more complicated than in the SM. The measurement of triple Higgs couplings (THCs) is key to determinethe shape of the multi-dimensional potential, which are best accessedvia di-Higgs produciton. So far most investigationsfocused on the THC of the SM-like Higgs boson discovered at the LHC in 2012. We go beyond these analyses and show how BSM THCs may be determined atcurrent and future colliders, including the HL-LHC, future linear e+e-colliers and a future muon collider.

Speaker: Alessandro Lella (Istituto Nazionale di Fisica Nucleare) Core-collapse Supernovae (SN) are among the most powerful astrophysical sources of feebly-interacting particles. Indeed, the extreme conditions of temperature and density reached after the gravitational collapse make the SN core a unique environment to have a significant production of novel exotic particles, such as axions and axion-like particles. In this seminar, I discuss how axions and ALPs could be copiously produced in a SN core by means of their coupling with nuclear matter. In particular, I will show that the ALP parameter space can be severely constrained by employing observations of the neutrino burst from SN 1987A. Moreover, ALPs are coupled to photons or leptons are provided with a vast phenomenology due to decays and oscillations in Galactic magnetic fields, leading to observable signatures, which may eventually shed light on controversial features characterizing the SN core.”

Speaker: Gustavo Conesa Balbastre (LPSC-CNRS Grenoble) The ALICE experiment at the LHC is devoted to test QCD predictions, and in particular, the measurement of the properties of the Quark-Gluon plasma created in ultra-relativistic heavy-ion collisions. Among the different probes that the experiment explores, neutral mesons and isolated photons are useful to study the jet-quenching effect in the QGP: the loss of energy of high energy partons (quarks and gluons) produced at the initial stages of the collision traversing the strongly interacting plasma. Such probes are measured in ALICE by its electromagnetic calorimeters PHOS and EMCal, combined with the central tracking systems. The Frascati-LNF-INFN and Grenoble-LPSC-CNRS groups had a strong involvement in the construction and exploitation of the EMCal calorimeter where I was involved. In this presentation I will present the different results obtained with the calorimeter during the LHC Run 1 and 2 data, concentrating on the isolated photons production.

Speaker: Livio Verra (Istituto Nazionale di Fisica Nucleare) The extremely large accelerating fields that can be excited in plasmas are orders of magnitudes larger than in conventional accelerators, and they could be used to miniaturise the ever-increasing footprint of light sources and high-energy physics facilities. In this seminar I will review the concepts of plasma wakefield acceleration, present the main experimental results of the field, and discuss the challenges on the path towards applications for high-energy physics.