Publications by Riccardo Rattazzi

Related publications (48)

Galileon as a local modification of gravity

In the Dvali-Gabadadze-Porrati (DGP) model, the "self-accelerating" solution is plagued by a ghost instability, which makes the solution untenable. This fact, as well as all interesting departures from general relativity (GR), are fully captured by a four- ...

American Physical Society2009

Electroweak baryogenesis above the electroweak scale

Riccardo Rattazzi, Luca Vecchi, Alfredo Glioti

Conventional scenarios of electroweak (EW) baryogenesis are strongly constrained by experimental searches for CP violation beyond the SM. We propose an alternative scenario where the EW phase transition and baryogenesis occur at temperatures of the order o ...

Springer Nature2019

Bounding scalar operator dimensions in 4D CFT

Riccardo Rattazzi, Alessandro Vichi

In an arbitrary unitary 4D CFT we consider a scalar operator phi, and the operator phi(2) defined as the lowest dimension scalar which appears in the OPE phi x phi with a nonzero coefficient. Using general considerations of OPE, conformal block decompositi ...

Springer Nature2008

Positive moments for scattering amplitudes

Francesco Riva, Riccardo Rattazzi, Marc Riembau Saperas, Brando Bellazzini

We find the complete set of conditions satisfied by the forward 2 -> 2 scattering amplitude in unitary and causal theories. These are based on an infinite set of energy dependent quantities (the arcs) which are dispersively expressed as moments of a positi ...

American Physical Society2021

Learning from radiation at a very high energy lepton collider

Riccardo Rattazzi, Andrea Wulzer, Siyu Chen, Alfredo Glioti, Lorenzo Ricci

We study the potential of lepton collisions with about 10 TeV center of mass energy to probe Electroweak, Higgs and Top short-distance physics at the 100 TeV scale, pointing out the interplay with the long-distance (100 GeV) phenomenon of Electroweak radia ...

Springer Nature2022

Identifying Large Charge operators

Riccardo Rattazzi, Alexander Monin, Gil Badel

The Large Charge sector of Conformal Field Theory (CFT) can generically be described through a semiclassical expansion around a superfluid background. In this work, focussing on U(1) invariant Wilson-Fisher fixed points, we study the spectrum of spinning l ...

Springer Nature2023

Gapped Goldstones at the cut-off scale: a non-relativistic EFT

Riccardo Rattazzi, Alexander Monin, Gabriel Francisco Cuomo, Angelo Esposito

At finite density, the spontaneous breakdown of an internal non-Abelian symmetry dictates, along with gapless modes, modes whose gap is fixed by the algebra and proportional to the chemical potential: the gapped Goldstones. Generically the gap of these sta ...

Springer Nature2021

Exploring the flavor symmetry landscape

Riccardo Rattazzi

We explore flavor dynamics in the broad scenario of a strongly interacting light Higgs (SILH). Our study focuses on the mechanism of partial fermion compositeness, but is otherwise as systematic as possible. Concretely, we classify the options for the unde ...

Stichting SciPost2025

Zoology of condensed matter: framids, ordinary stuff, extra-ordinary stuff

Riccardo Rattazzi

We classify condensed matter systems in terms of the spacetime symmetries they spontaneously break. In particular, we characterize condensed matter itself as any state in a Poincare-invariant theory that spontaneously breaks Lorentz boosts while preserving ...

Springer Nature2015

Feynman diagrams and the large charge expansion in 3-epsilon dimensions

Riccardo Rattazzi, Alexander Monin, Gil Badel, Gabriel Francisco Cuomo

In arXiv:1909.01269 it was shown that the scaling dimension of the lightest charge n operator in the U (1) model at the Wilson-Fisher fixed point in D = 4 - epsilon can be computed semiclassically for arbitrary values of lambda n, where lambda is the pertu ...

2020

On Partial Compositeness and the CP asymmetry in charm decays

Riccardo Rattazzi, Duccio Pappadopulo, Paolo Lodone, Boaz Keren Zur, Luca Vecchi

Recently, the LHCb and CDF Collaborations reported the measure of an unexpectedly large direct CP asymmetry in D meson decays. In this paper we ask if new physics associated with Partial Compositeness could plausibly explain this result. We find that Compo ...

Elsevier Science Bv2013

The quantum mechanics of perfect fluids

Riccardo Rattazzi, Solomon G Shamsuddin Osman Endlich

We consider the canonical quantization of an ordinary fluid. The resulting long-distance effective field theory is derivatively coupled, and therefore strongly coupled in the UV. The system however exhibits a number of peculiarities, associated with the vo ...

Springer Nature2011

Tetraquarks at large M and large N

Riccardo Rattazzi, Majid Ekhterachian, Héloïse Allaman, Filippo Nardi, Stefan Stelzl

We study tetraquarks in large N QCD with heavy quarks, in the domain where non-relativistic quantum mechanics offers an adequate approximation. Within the regime of validity of the Born-Oppenheimer approximation, we systematically study and explicitly cons ...

Springer Nature2024

Strong double higgs production at the LHC

Riccardo Rattazzi, Roberto Contino

The hierarchy problem and the electroweak data, together, provide a plausible motivation for considering a light Higgs emerging as a pseudo-Goldstone boson from a strongly-coupled sector. In that scenario, the rates for Higgs production and decay di ff er ...

Springer Nature2010

The quantum perfect fluid in 2D

Riccardo Rattazzi

We consider the field theory that defines a perfect incompressible 2D fluid. One distinctive property of this system is that the quadratic action for fluctuations around the ground state features neither mass nor gradient term. Quantum mechanically this po ...

2024

Theoretical constraints on the Higgs effective couplings

Riccardo Rattazzi, Alessandro Vichi

We derive constraints on the sign of couplings in an effective Higgs Lagrangian using prime principles such as the naturalness principle, global symmetries, and unitarity. Specifically, we study four dimension-six operators, O-H, O-y, O-g, and O-gamma, whi ...

Springer Nature2010

Strong Higgs interactions at a linear collider

Riccardo Rattazzi, Duccio Pappadopulo, Andrea Thamm, Roberto Contino

We study the impact of Higgs precision measurements at a high-energy and high-luminosity linear electron positron collider, such as CLIC or the ILC, on the parameter space of a strongly interacting Higgs boson. Some combination of anomalous couplings are a ...

Springer Nature2014

Towards a muon collider

Riccardo Rattazzi, Xavier Buffat, Andrea Wulzer, Roberto Franceschini, Varun Sharma, Alexej Grudiev, Riccardo Torre, Siyu Chen, Alfredo Glioti, Xiaoran Zhao, Lorenzo Ricci, Brian Quinn Henning, Filippo Nardi

A muon collider would enable the big jump ahead in energy reach that is needed for a fruitful exploration of fundamental interactions. The challenges of producing muon collisions at high luminosity and 10 TeV centre of mass energy are being investigated by ...

Springer2023

On the effect of resonances in composite Higgs phenomenology

Riccardo Rattazzi, Duccio Pappadopulo, Roberto Contino

We consider a generic composite Higgs model based on the coset SO(5)= SO(4) and study its phenomenology beyond the leading low-energy effective lagrangian approximation. Our basic goal is to introduce in a controllable and simple way the lowest-lying, poss ...

Springer Nature2011

Lopsided gauge mediation

Riccardo Rattazzi, Roberto Franceschini, Duccio Pappadopulo, Andrea De Simone

It has been recently pointed out that the unavoidable tuning among supersymmetric parameters required to raise the Higgs boson mass beyond its experimental limit opens up new avenues for dealing with the so called mu-B-mu problem of gauge mediation. In fac ...

Springer Nature2011