Seminario di Fisica Teorica –
Over the past two decades, f(R) gravity has been at the forefront of providing an alternative to dynamical dark energy to explain the origin of late-time acceleration in the universe. This talk will provide a survey of work that has been done in this area using covariant methods, dealing with diverse topics from cosmological dynamics to gravitational lensing and perturbations of black holes.
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Seminario di Fisica Teorica-
In the first part of the presentation, I will present a study of the spectra and strong decay widths of heavy baryons. The masses of single heavy baryons up to the D-wave have been calculated within a constituent quark model, employing both the three-quark and quark-diquark schemes. The decay widths of the ground and excited single heavy baryons into the heavy single baryon-(vector/pseudoscalar) meson pairs and the (octet/ decuplet) baryon-
(pseudoscalar/vector) heavy meson pairs, have been calculated. Moreover, I will discuss why the presence or absence of the ρ-mode excitations in the experimental spectrum is the key to distinguishing between the quark-diquark and three-quark behaviours, as it was originally pointed out in. The quantum number assignments and predictions for mass spectra and strong-decay widths are in agreement with the available data. These findings provide valuable
guidance for future measurements in experiments as ATLAS, CMS, LHCb, Belle, and Belle II.
In the second part of this talk, I will present a new application of the Interacting Boson Fermion-Fermion Model (IBFFM) for describing double charge exchange reactions. The study of double charge exchange reactions induced by heavy ions involving candidate nuclei for neutrinoless double beta decay is a complex task carried out by the NUMEN collaboration [5], to which I belong. This investigation faces the intricacies of complex odd-odd intermediate nuclei in sequential double charge exchange processes. I will offer a comprehensive description of heavy odd-odd nuclei using the (IBFFM). Additionally, I will outline the methodology for describing transfer operators within this framework.
Finally, I will explore the potential applications of our results in future reaction codes for describing double charge exchange reactions.
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Seminario di Fisica Teorica-
The advent of noisy-intermediate-scale quantum (NISQ) devices is opening new horizons for fundamental theoretical research. When viewed as experimental platforms for many-body quantum physics, NISQ devices can be conceptualized as systems evolving according to discrete sequences of few-body unitary processes, local projective measurements, and feedback. These ingredients give rise to new qualitative features and universal phenomena out of equilibrium, such as the recently discovered entanglement measurement-induced phase transitions (MIPTs). In the first part of the talk, I will provide an overview of the recent literature on the subject, introducing different quantum-circuit models for non-equilibrium many-body physics and the MITPs. In the second part, I will focus on some of my recent work on explicit models, showing either interesting new phenomena or allowing for analytic insight based on mappings to statistical mechanics problems.
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Seminario di Fenomenologia –
In this talk I will describe how the common treatment of heavy quark mass effects in either the initial of final state can lead to important issues and how can we construct a more effective way of dealing with massive quarks in a consistent way both theoretically and practically.
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Seminario Generale
The Precision Proton Spectrometer (PPS) was developed by the CMS and TOTEM Collaborations and started to be used extensively during Run 2 of the LHC. It is a powerful tool for advancing new measurements with forward proton tags and beyond the standard model searches. The commissioning of this new detector involves understanding different aspects of forward proton reconstruction (alignment and optics calibrations, radiation damage, pileup contributions and validation using standard model candles).
In this seminar I’ll illustrate how PPS can be used by focussing on a generic search for the associated production of a Z boson or a photon with an additional unspecified massive particle X in proton-tagged events from proton-proton (pp) collisions at √s =13 TeV, recorded in 2017. The so-called missing mass spectrum is analysed in the 600–1600 GeV range and a fit is performed to search for possible deviations from the background expectation. No significant resonant deviations in data with respect to the background predictions have been observed. Model-independent upper limits on the visible production cross section of pp → pp + Z/γ + X are set. Results from other recent searches with PPS and Run 2 will also be summarized.
Neutrino experiments such as MiniBooNE and MicroBooNE produce a large quantity of secondary muons. This provides an
interesting opportunity to search for BSM particles that may
preferentially couple to the muon. In my talk, I will present a
scenario where neutrino experiments are particularly suitable for
studying BSM models, and show how these experiments have excluded
certain regions where a BSM scalar could explain the g-2 anomaly.
Seminario di Fisica Teorica-
On a space with a group action, the equivariant localization theorem allows one to compute integrals using only local information. We shall see how this can be applied to AdS/CFT to compute various supersymmetric gravity observables without solving the equations of motion, using just topological information.
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Seminario di Fisica Teorica-
The standard cosmological model (LCDM) has shown a great ability to explain cosmological observations throughout the past 3 decades. Despite this, several of its component are still a mystery from the theoretical point of view; together with the observational tensions recently found between different measurements of its parameters, this motivates the search for alternative models or, at least, a thorough testing of LCDM.
In this talk, I will focus mostly on tests of one of the crucial assumptions done in cosmology, i.e. that General Relativity is a good description of gravity at cosmological scale, showing recent constraints and how upcoming surveys might improve our knowledge.
In addition to this I will also show results on other more fundamental assumptions, namely the validity of the Distance Duality Relation and on the possible variation of the fine-structure constant. Finally, I will also briefly summarize how new cosmological observables might shed new light on the dark component of the standard cosmological model.
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Seminario di Fisica Teorica-
Abstract: I will review the old idea of studying QFTs on AdS background to control strong coupling effects. We study dynamical mass generation in some 2d asymptotically free theories in AdS backgrounds. At weak coupling a Dirichlet boundary condition ensures that the bulk field is exactly massless.
At strong coupling a marginal boundary singlet operator appears, destabilizing the BCFT and leading to a boundary phase transition. The endpoint of this boundary flow allows for a massive bulk phase and interpolates with the flat spacetime physics. We conjecture that such a phenomenon is also responsible for confinment in 4d gauge theories on AdS background.
Based on work to appear with Lorenzo di Pietro, Shota Komatsu and Ziming Ji.
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Seminario di Fisica Torica
In this talk, I will present a fracton gravity gauge theory based on a covariant version of the monopole-dipole-momentum algebra. In the presence of a suitable background field, the theory includes a massive two-form and a massless symmetric two-index tensor. The latter transforms only under longitudinal diffeomorphisms, making the massless sector similar to linearized gravity, but with additional modes of lower spin. I will show that the theory can be consistently coupled to a curved background metric and discuss its possible interaction terms with itself and with matter. In addition, I will present a map between solutions of linearized gravity in Kerr-Schild form and solutions of fracton gravity coupled to matter.
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