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Daniele Dominici

Publications and source records attributed to Daniele Dominici.

At least 19 recordsLinked to original sources
arXiv2026

Massive and massless particles in Mielke--Baekler geometries

The Mielke--Baekler geometries are three-dimensional reductive homogeneous spacetimes together with a choice of invariant connection which is compatible with a lorentzian metric. The spacetimes generalise Minkowski and (anti)de~Sitter spacetimes in that the invariant metric connection can have torsion, a peculiarity of three dimensions. Using coadjoint orbits and the techniques of nonlinear realisations, we construct worldline actions for massive and massless spinning particles moving in these spacetimes. We pay particular attention to the so-called teleparallel branch, in which the curvature of the invariant connection vanishes. Apart from the trivial Minkowski case, this singles out anti-de~Sitter spacetime, as the only of these lorentzian manifolds admitting an invariant Weitzenböck connection; that is, a flat connection with torsion. The introduction of a Wess--Zumino term describing spin has, as a main consequence, the appearance of dynamical sectors (denoted ``regular'' and ``critical''), with a different number of physical degrees of freedom. In particular, in the massive case, we discuss the formulation of the dynamics in terms of either the Weitzenböck or the Levi-Civita connection, and the emergence of a Papapetrou-type forcing term in the critical sector. For the massless particle we study the Noether symmetries of the action, which, for the spinless case, include the conformal transformations. For nonzero spin, only the Killing subset survives as genuine Noether transformations in the regular sector, while in the critical sector any conformal Killing contribution can be set to zero by a gauge transformation.

hep-th↗
arXiv2026

From Florence to Fermions: a historical reconstruction of the origins of Fermi's statistics one hundred years later

Aim of this paper is to retrace the path that led the young Enrico Fermi to write his paper on the statistics of an ideal monatomic gas. This discovery originated in his interest, which he had shown since his formative years, in the absolute entropy constant and in the problems he highlighted in Sommerfeld's quantization in the case of identical particle systems. The fundamental step taken by Fermi in writing his work on statistics was to apply the Exclusion Principle, formulated for electrons in an atom and which could therefore have been a pure effect due to dynamics, to a system of non-interacting particles.

physics.hist-ph↗
arXiv2025

A Celestial Kinematical Interpretation for an Extended BMS$_4$

Motivated by the work of Longhi and Materassi, who constructed a realisation of the (centreless) BMS$_4$ algebra for the massive Klein-Gordon field in $3+1$, we build a realisation of the (centreless) massless BMS$_4$ algebra including super-rotations. This realisation depends only on the momenta in the lightcone expressed in celestial coordinates without any reference to the Klein--Gordon field. The quadratic Casimir of the Lorentz algebra is written in terms of a second order differential operator and the volume form plays an essential role in this construction. The BMS$_4$ algebra in terms of vector fields shows its kinematical nature, like the Poincaré algebra. We also construct a dynamical realisation of BMS$_4$ from the symplectic structure on the solutions of the massless four-dimensional Klein--Gordon field in terms of quadratic expressions of the Fourier modes and plane waves invariant under translations. Using the Mellin transform, we rewrite the Klein--Gordon field in terms of the boost invariant basis, and write down the corresponding BMS$_4$ realization. We also provide the relation with spherical harmonics, linking our results with the solutions of Longhi-Materassi, which are in fact a subset of ours.

hep-th↗
arXiv2025

The history of the Arcetri Physics Institute from the 1920s to the end of the 1960s

The history of the Arcetri Institute of Physics at the University of Florence is analyzed from the beginning of the 20th century to the 1960s. Thanks to the arrival of Garbasso in 1913, not only did the Institute gain new premises on Arcetri hill, but also hosted brilliant young physicists such as Rita Brunetti, Enrico Fermi, Franco Rasetti in the '20s and Enrico Persico, Bruno Rossi, Gilberto Bernardini, Daria Bocciarelli, Lorenzo Emo Capodilista, Giuseppe Occhialini and Giulio Racah in the '30s, engaged in the emerging fields of Quantum Mechanics and Cosmic Rays. This internationally renowned Arcetri School dissolved in the late 1930s mainly for the transfer of its protagonists to chairs in other Italian or foreign universities. After the war, the legacy was taken up by some students of this school who formed research groups in the fields of nuclear physics and elementary particle physics. As far as theoretical physics is concerned, after the Fermi and Persico periods, these studies enjoyed a new expansion in the sixties thanks to the arrival of Raoul Gatto who created in Arcetri the first Italian school of theoretical physics.

physics.hist-ph↗
arXiv2024

Non equivalence of Carroll limits in relativistic string theory

We construct new Carroll strings in flat space by considering the Carroll limit of equivalent relativistic string theories at classical level. In the limit these Carroll strings are no longer equivalent and have different degrees of freedom. This fact is due to a general phenomenon that the configuration space and canonical Lagrangians are no longer equivalent after a singular redefinition of the variables and of the parameters of the starting Lagrangians.

hep-th↗
arXiv2023

Superconformal interacting particles

The free massless superparticle is reanalysed, in particular by performing the Gupta-Bleuler quantization, using the first and second class constraints of the model, and obtaining, as a result, the Weyl equation for the spinorial component of the chiral superfield. Then we construct a superconformal model of two interacting massless superparticles from the free case by the introduction of an invariant interaction. The interaction introduces an effective mass for each particle by modifying the structure of fermionic constraints, all becoming second class. The quantization of the model produces a bilocal chiral superfield. We also generalise the model by considering a system of superconformal interacting particles and its continuum limit.

hep-th↗
arXiv2023

Two interacting conformal Carroll particles

In this note we analyse two different models of two interacting conformal Carroll particles that can be obtained as the Carrollian limit of two relativistic conformal particles. The first model describes particles with zero velocity and exhibits infinite dimensional symmetries which are reminiscent of the BMS symmetries. A second model of interaction of Carrollian particles is proposed, where the particles have non zero velocity and therefore, as a consequence of the limit c to 0, are tachyons. Infinite dimensional symmetries are present also in this model.

hep-th↗
arXiv2023

A brief history of Florentine physics from the 1920s to the end of the 1960s

The history of the Institute of Physics at the University of Florence is traced from the beginning of the 20th century, with the arrival of Antonio Garbasso as Director (1913), to the 1960s. Thanks to Garbasso's expertise, not only did the Institute gain new premises on Arcetri hill, where the Astronomical Observatory was already located, but it also formed a brilliant group of young physicists made up of Enrico Fermi, Franco Rasetti, Enrico Persico, Bruno Rossi, Gilberto Bernardini, Daria Bocciarelli, Lorenzo Emo Capodilista, Giuseppe Occhialini and Giulio Racah, who were engaged in the emerging fields of Quantum Mechanics and Cosmic Rays. This Arcetri School disintegrated in the late 1930s for the transfer of its protagonists to chairs in other universities, for the environment created by the fascist regime and, to some extent, for the racial laws. After the war, the legacy was taken up by some students of this school who formed research groups in the field of nuclear physics and elementary particle physics. As far as theoretical physics was concerned, after the Fermi and Persico periods these studies enjoyed a new expansion towards the end of the 1950s, with the arrival of Giacomo Morpurgo and above all, that of Raoul Gatto, who created the first real Italian school of Theoretical Physics at Arcetri.

physics.hist-ph↗
arXiv2021

Spin-1 resonances

Spin-1 resonances are naturally present in composite Higgs frameworks. We first review a model independent approach to parametrize a single additional heavy triplet and then we consider more realistic models arising in composite Higgs scenarios where a larger number of spin-1 resonances is expected. In these cases, finite width and interference effects can heavily affect the bounds extracted from the data.

hep-ph↗
arXiv2018

The teacher of the gattini (kittens)

The figure of Raoul Gatto, who died in 2017, is remembered here, with an illustration of his career and the main results of his research, along with the personal memories of some of those who worked with him.

physics.hist-ph↗
arXiv2015

Variational approach to thermal masses in compactified models

We investigate by means of a variational approach the effective potential of a 5D U(1) scalar model at finite temperature and compactified on S^1 and S^1/Z_2 as well as the corresponding 4D model obtained through a trivial dimensional reduction. We are particularly interested in the behaviour of the thermal masses of the scalar field with respect to the Wilson line phase and the results obtained are compared with those coming from a one-loop effective potential calculation. We also explore the nature of the phase transition.

hep-ph↗
arXiv2013

Dynamical sectors of a relativistic two particle model

We reconsider a model of two relativistic particles interacting via a multiplicative potential, as an example of a simple dynamical system with sectors, or branches, with different dynamics and degrees of freedom.The presence or absence of sectors depends on the values of rest masses. Some aspects of the canonical quantization are described. The model could be interpreted as a bigravity model in one dimension.

hep-th↗
arXiv2013

Discovery and Mass Spectroscopy via Mixed Di-Boson Production at the LHC in a 4-Site Model with a Composite Higgs Boson

We investigate the scope of the Large Hadron Collider (LHC) in probing the parameter space of a 4-Site (4S) model supplemented by one composite Higgs state. We concentrate on the yield of `mixed' di-boson production giving three leptons and missing (transverse) energy in the final state, i.e., events induced via the sub-process $q\bar q' -> l^+ν_l l^{'+}l^{'-}$ + ${\rm{c.c.}}$, where $q,q'$ are quarks and $l,l'=e,μ$ in all possible combinations, signature which enables the production in the intermediate steps of all additional -- with respect to the Standard Model (SM) -- neutral and charged gauge bosons belonging to the spectrum of this scenario, all of which in resonant topologies. We not only find this channel to be accessible over the background but also show that, after a dedicated cut-based analysis, kinematical reconstruction of all such resonances is always possible. We finally compare the yield of the mixed di-boson mode to that of the `charged' di-boson one and find that the former is of lesser scope than the latter at smaller gauge boson masses but it overcomes it at higher values, thereby revealing itself a viable search mode covering new regions of parameter space.

hep-ph↗
arXiv2012

Interference effects in heavy W'-boson searches at the LHC

Interference effects are widely neglected in searches for new physics. This is the case in recent publications on searches for W'-bosons using leptonic final states. We examine the effects of interference on distributions frequently used to determine mass limits for possible W'-bosons and show that there are important qualitative effects on the behaviour of the new physics signal. There are two main consequences. Firstly, exclusion limits where interferences effects have not been considered are likely to have been overestimated. Secondly, presenting experimental results as a function of a transverse mass cut rather than in terms of the contribution of new physics to the total cross-section would be more informative.

hep-ph↗
arXiv2012

Indirect Sensitivity to Heavy Z' Bosons at a Multi-TeV e+e- Collider

We compare the phenomenology of two models, the so-called minimal Z' and an effective model for a SM-like Higgs realised as a composite state of a new strong interaction, at a multi-TeV linear collider in the hypothesis that the new physics is at a scale beyond the direct reach of the machine.

hep-ph↗
arXiv2011

Effective chiral Lagrangians for new vector bosons to O(p^4) order

If the SM Higgs boson does not exist, electroweak symmetry breaking may be realized via a strong interaction with a typical scale Lambda > 1 TeV. Resonances from the strong sector may help to unitarize WW scattering, which becomes strong in the absence of an Higgs field, and could be detected at the LHC. In this paper we describe such a scenario, in the minimal case in which only one new vector resonance is present, via a chiral SU(2) x SU(2)/SU(2) lagrangian also including all possible invariant terms up to O(p^4) order (assuming a parity symmetry in the strong sector). The O(p^4) invariants are not usually taken into account in similar studies in the literature; however, they have been shown to be potentially important, at least, to reconcile this kind of scheme with electroweak precision tests. Here we use the O(p^4) lagrangian to study the scattering amplitudes for the pi pi sector, investigating the partial wave unitarity properties of the model and its cut-off energy scale. We obtain constraints on the parameter space and compare our result to the one obtained with just the O(p^2) lagrangian, finding that the contribution of the new operators is indeed significant.

hep-ph↗
arXiv2011

W' production at the LHC in the 4-site Higgsless model

We study the phenomenology of the 4-site Higgsless model, based on the $SU(2)_L\times SU(2)_1\times SU(2)_2\times U(1)_Y$ gauge symmetry, at present colliders. The model predicts the existence of two neutral and four charged extra gauge bosons, Z1,Z2,W1,W2. In this paper, we focus on the charged gauge sector. We first derive limits on W1,W2-boson masses and couplings to SM fermions from direct searches at the Tevatron. We then estimate at the 7 TeV LHC the exclusion limits with the actual L=1 fb-1 and the discovery potential with the expected L=10 fb-1. In contrast to the minimal (or 3-site) Higgsless model which predicts almost fermiophobic extra gauge bosons, the next-to-minimal (or 4-site) Higgsless model recovers sizeable W1,W2-boson couplings to ordinary matter, expressing the non-fermiophobic multiresonance inner nature of extra-dimensional theories. Owing to this feature, we find that in one year from now the new heavy gauge bosons, W1 and W2, could be discovered in the final state with an electron and large missing transverse energy at the 7 TeV LHC for W1,W2-boson masses in the TeV region, depending on model parameters.

hep-ph↗