Person

Riccardo Rattazzi

Related publications (49)

Large field excursions and approximate discrete symmetries from a clockwork axion

We present a renormalizable theory of scalars in which the low-energy effective theory contains a pseudo-Goldstone boson with a compact field space of 2 pi F and an approximate discrete shift symmetry Z(Q) with Q >> 1, yet the number of fields in the theor ...

American Physical Society2016

The composite twin Higgs scenario

Riccardo Rattazzi, Andrea Wulzer, Davide Greco

Based on an explicit model, we propose and discuss the generic features of a possible implementation of the Twin Higgs program in the context of composite Higgs models. We find that the Twin Higgs quadratic divergence cancellation argument can be uplifted ...

Springer Nature2015

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

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

The local Callan-Symanzik equation: structure and applications

Riccardo Rattazzi, Florent Baume, Boaz Keren Zur, Lorenzo Vitale

The local Callan-Symanzik equation describes the response of a quantum field theory to local scale transformations in the presence of background sources. The consistency conditions associated with this anomalous equation imply non-trivial relations among t ...

Springer Nature2014

The alpha-theorem and the asymptotics of 4D quantum field theory

Riccardo Rattazzi

We study the possible IR and UV asymptotics of 4D Lorentz invariant unitary quantum field theory. Our main tool is a generalization of the Komargodski-Schwimmer proof for the alpha-theorem. We use this to rule out a large class of renormalization group flo ...

Springer Nature2013

A first top partner hunter's guide

Riccardo Rattazzi, Andrea Wulzer, Andrea De Simone

We provide a systematic effective lagrangian description of the phenomenology of the lightest top-partners in composite Higgs models. Our construction is based on symmetry, on selection rules and on plausible dynamical assumptions. The structure of the res ...

Springer Nature2013

A naturally light dilaton

Riccardo Rattazzi, Duccio Pappadopulo, Paolo Lodone, Lorenzo Vitale

Goldstone's theorem does not apply straightforwardly to the case of spontaneously broken scale invariance. We elucidate under what conditions a light scalar degree of freedom, identifiable with the dilaton, can naturally arise. Our construction can be cons ...

Springer Nature2013

Implications of LHCb measurements and future prospects

Riccardo Rattazzi, Abhisek Datta, Anton Petrov

During 2011 the LHCb experiment at CERN collected 1.0 fb(-1) of root s = 7 TeV pp collisions. Due to the large heavy quark production cross-sections, these data provide unprecedented samples of heavy flavoured hadrons. The first results from LHCb have made ...

Springer2013

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

Probing the scattering of equivalent electroweak bosons

Riccardo Rattazzi, Andrea Wulzer, Pascal Borel, Roberto Franceschini

We analyze the kinematic conditions under which the scattering of equivalent massive spin-1 vector bosons factorizes out of the complete process. In practice, we derive the conditions for the validity of the effective W approximation, proposed long ago but ...

Springer Nature2012

Unificaxion

Riccardo Rattazzi

Dark matter, gauge coupling unification, and the strong CP problem find a common and simple solution (in the absence of naturalness) within axion models. We show that such a solution, even without specifying the details of the model implementation, makes t ...

Elsevier Science Bv2012

Operator product expansion convergence in conformal field theory

Riccardo Rattazzi, Johnny Espin Pais, Duccio Pappadopulo

We clarify questions related to the convergence of the operator product expansion and conformal block decomposition in unitary conformal field theories (for any number of spacetime dimensions). In particular, we explain why these expansions are convergent ...

American Physical Society2012

Central charge bounds in 4D conformal field theory

Riccardo Rattazzi, Alessandro Vichi

We derive model-independent lower bounds on the stress tensor central charge C-T in terms of the operator content of a 4-dimensional conformal field theory. More precisely, C-T is bounded from below by a universal function of the dimensions of the lowest a ...

American Physical Society2011

energy's and amplitudes' positivity (vol 05, 095, 2010)

Riccardo Rattazzi

We correct typos in eq. (2.41) and (2.42) of ref. [1]. This has several repercussions for the equations of section 2.3, but none for the subsequent sections or for the conclusions of the paper ...

Springer Nature2011

Bounds in 4D conformal field theories with global symmetry

Riccardo Rattazzi, Alessandro Vichi

We explore the constraining power of OPE associativity in 4D conformal field theory with a continuous global symmetry group. We give a general analysis of crossing symmetry constraints in the 4-point function , where phi is ...

2011

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

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

The other natural two Higgs doublet model

Jan Dalibor Mrazek, Riccardo Rattazzi, Andrea Wulzer

We characterize models where electroweak symmetry breaking is driven by two light Higgs doublets arising as pseudo-Nambu-Goldstone bosons of new dynamics above the weak scale. They represent the simplest natural two Higgs doublet alternative to supersymmet ...

2011

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