Tag Archives: Evento scientifico

Speaker: Emanuele Rosi The detection of gravitational waves (GW) after several decades from their formulation opened a new window to observe the universe. The new generation of GW detectors is expected to span a large parameter space, requiring theoretical physicist to develop different approaches to face the two body problem in General Relativity, each of them based on some perturbative expansion, e.g. Post Newtonian, Post Minkowskian (PM), Self Force. Among these, Effective Field Theories (EFTs) and quantum amplitudes are used together to extract scattering observables which also have a meaningful classical limit, both in the PM and Self Force frameworks. We analyse the high energy (Regge) regime of spinless two body scattering within this approach, by the prospect of isolating universal effects and to give insights on the resummation of the PM observables at higher orders, made possible by the simplicity of the calculations in the Regge limit. A sequence of classical Feynman diagrams is recognised to contribute to the leading power and leading log(s/t) in the high energy expansion. We compute them up to four loops (5PM) and use analyticity properties of the S Matrix to maximise the information that we can extract at any PM order.

Alessandro Pilloni (UniME & INFN CT) In the last 20 years, the discoveries of tenths of exotic candidates has challenged the simplistic quark model predictions, most notably in the charmonium sector. While no consensus on their nature has been reached in the community, it is time to have a critical review of our understanding of the sector, to see what developments can be expected in the near future. I will review the most relevant experimental observations of the last few years, and discuss the theoretical and phenomenological tools that will help us to move forward in understanding this complicate sector of QCD.

Speaker: Marco Scodeggio (Istituto Nazionale di Fisica Nucleare) Since 2009, the BESIII experiment at the BEPCII lepton collider has played a central role in hadron spectroscopy, in measurements of charmed-hadron decay properties, and in precision QCD studies at the interface between the perturbative and non-perturbative regimes. Recently, an extensive upgrade program has been completed: the accelerator luminosity in the high center of mass energy region has been increased by a factor of three, and the innermost tracking system has been replaced by the new CGEM-IT, an inner tracker based on cylindrical gas electron multiplier (GEM) technology, originally developed for the KLOE-2 experiment at LNF. In this seminar, the current status of the BESIII experiment will be presented, highlighting some recent physics results and discussing the status of the CGEM-IT detector.

Speaker: Catalina Oana Curceanu (Istituto Nazionale di Fisica Nucleare) The theory of strong interactions — Quantum Chromodynamics (QCD) — still lacks crucial experimental input in the low-energy regime, to understand how the transition from quarks and gluons to hadrons occurs. Among the most sensitive probes of this domain are kaonic atoms, in which a negatively charged kaon replaces an electron and orbits the nucleus. The energy-level shifts and widths of such exotic systems provide direct information on the kaon–nucleon and kaon nucleus interactions, key ingredients for understanding hadronic matter and the physics of dense astrophysical objects such as neutron stars. At the DAΦNE collider in Frascati, the SIDDHARTA and SIDDHARTA-2 collaborations have pioneered a new generation of precision measurements by combining DAΦNE’s unique low-energy kaon beams with state-of-the-art Silicon Drift Detectors (SDDs). After achieving the most precise data on kaonic hydrogen and other light systems, we have now finalized the first measurement of kaonic deuterium, a long-sought milestone, and have opened the path to QED tests with exotic atoms. In this seminar, I will introduce the physics of kaonic atoms, present our most recent results, and outline future perspectives. Experiments at DAΦNE offer a unique opportunity worldwide to finally unveil the secrets of QCD and QED in the strangeness sector and to deepen our understanding of the role of strange matter, up to the stars.  

Speaker: Gael Finauri (TUM) In this talk I will review recent progress in the inclusive extraction of Vcb in the Standard Model through global fits to kinematic moments of the differential distribution. I will briefly discuss the theoretical framework of the calculation as well as the phenomenological implications. Furthermore I will present a recent work in the inclusion of New Physics effects in the global fit, constraining the available parameter space for the Wilson coefficients of the weak effective theory.

Speaker: Davide Milillo (Istituto Nazionale di Fisica Nucleare) A minimal abelian extension of the SM is considered, based on the introduction of a new massive, neutral gauge boson Z′. Due to the specific solution adopted for the cancellation of gauge anomalies, the new mediator has flavor non-universal couplings to quarks and leptons. As a result, quark and lepton sectors constrain each other to prevent large deviations from SM predictions. Moreover, correlations emerge between quark flavor and lepton flavor violating processes, such as lepton flavor violating B meson and purely leptonic decays. In this seminar, after reviewing the motivations and strategies for the search of BSM physics, the key aspects and predictions of this model for rare and SM-forbidden decays will be presented.  

INFN has a long-standing tradition in the use of synchrotron radiation and in the construction of accelerators dedicated to its use. The tradition started with the use of the ADONE 1.5 GeV electron storage ring up to 1993 and continued with the DAFNE electron-positron 0.5 GeV collider. INFN is now developing at Frascati a new user facility EuPRAXIA@SPARC_Lab based on plasma acceleration. This new facility in the framework of the EuPRAXIA EU project should produce FEL radiation beams for a wide range of applications. During this workshop the story of synchrotron radiation at Frascati from its early beginnings (e-synchrotron) up to nowadays will be reported with talks related to the past and to all the people who made it possible, to the present and to the future scientific activities.

Speaker: Gia Dvali (LMU and MPP. Munich) In this talk we first review why the CP-violating θ-vacuum is a built-in feature of QCD and how the mass of the η′-meson provides a direct experimental evidence for it. We then explain how the axion protects CP dynamically and define the axion-quality measure. This discussion, in particular, will make it transparent that the η′-meson is nothing but a poor-quality axion. Next, we introduce the so-called gauge formulation of axion in which the axion emerges as intrinsic part of QCD gauge redundancy without the need of any anomalous global symmetry. By the power of gauge symmetry, the gauge axion has an exact quality, as it is protected agains arbitrary continuous deformations of the theory. Next, we show that in a generic gauge theory the elimination of the θ vacua by an anomalous symmetry is correlated with the existence of a pseudo-scalar particle that non-linearly realizes that symmetry. Applied to the electroweak sector, this implies the existence of a new particle, a so-called ηw-meson, which is sourced by the B+L-anomaly and gets its mass from the topological susceptibility of the electroweak vacuum. We then discuss how gravity opens up a whole new perspective on the axion, promoting it into a consistency issue. Namely, once coupled to gravity, every topologically non-trivial gauge sector must be accompanied by the axion of exact quality. This requirement must be fulfilled by gravity itself which, due to Eguchi-Hanson instantons, possesses the CP-violating θ-vacuum. Strikingly, this implies the existence of …

The Workshop on Light Dark Sectors @ LNF (LDS@LNF) will gather researchers to discuss recent progress in the study of light dark sectors (covering light dark matter, axion-like particles, dark photons, and related scenarios). The program will cover topics ranging from theoretical motivations to novel experimental strategies, with the aim of encouraging exchanges and fostering collaborations within the community. This workshop is also supported by the PRIN2022K4B58X project “AxionOrigins: Towards a Complete Theory for the Origin of the Axion” (PI: L. Di Luzio), a collaborative effort involving INFN, the University of Padua, and Sapienza University of Rome. The meeting serves as the closing event of this initiative. The workshop will take place in the Salvini Auditorium (Building 36, access via the LNF secondary entrance at Via E. Fermi, 60 – see map). (Talks by invitation only)

Speaker: Laura Miller The nature of dark matter remains one of the largest open questions in particle physics. Despite numerous theories and experimental searches, both small-scale and large-scale, it has so far remained unobserved at the particle level. The DarkLight experiment located at TRIUMF in Vancouver, Canada aims to leverage the ARIEL electron linear accelerator to search for a new dark sector force carrier in the 10-20 MeV range. Such a force carrier could undergo kinetic mixing with Standard Model photon, and thus could provide possible explanations for experimental anomalies such as the X17. As the DarkLight experiment has recently been installed and has begun commissioning, this talk will primarily focus on progress up to this point and future plans.