In this talk I will introduce a rather recent scaling method allowing to perform the usual equilibrium finite-size scaling analysis for continuous phase transitions in the out-of-equilibrium relaxation regime. Such an approach is most valuable for all those system which show a very slow critical dynamics – i.e. a high value of the dynamic exponent z – and systems which are computationally expensive to simulate. I will show results obtained for the three-dimensional IsingSpin Glass (z ~ 6.8) relaxed via the Metropolis dissipative dynamics. The values of the critical exponents and critical temperature are the first out-of-equilibrium estimates to be compatible and comparable in precision with those obtained from the "Janus" dedicated supercomputer. Since the method is based on Renormalization Group arguments it turns out to be completely general and, potentially, of wide interest in different domains. Furthermore, I will summarize some results obtained in the development of the numerical implementation of such simulations optimized for GPU architectures. [1] M. Lulli, G. Parisi and A. Pelissetto, PRE 93, 032126 [1](2016), http://dx.doi.org/10.1103/PhysRevE.93.032126 [2] [2] M. Lulli, M. Bernaschi and G. Parisi, CPC 196 (2015) 290–303, http://dx.doi.org/10.1016/j.cpc.2015.06.019 [3]

Scopri di più »# Tag Archives: Evento scientifico

## MASSIVE GRAVITINOS IN CURVED SPACE TIME

We derive mass formulae for broken(and unbroken) supersymmetry in curved space-time. These formulae are applicable to De-Sitter configurations as in the case of inflation. For unbroken supersymmetry in Anti-de-Sitter they describe the deviation from flat space formulae due to the space-time curvature.

Scopri di più »## Higgs precision physics at the LHC: the case of soft gluons

The investigation of Higgs boson properties is one of the most important activities in particle physics nowadays. Such studies can provide invaluable insights on the nature of beyond the Standard Model physics, complementing the ongoing direct searches. The increasing precision of the experimental measurements at the LHC calls for correspondingly good theoretical predictions for Higgs production processes. In this context, calculations of QCD corrections to the production rates for these processes are of central relevance to the LHC physics programme. A major contribution to higher order QCD corrections originates from multiple soft gluon emission and can be treated systematically to all orders by means of resummation techniques. In this talk I will review the application of resummation techniques to Higgs boson physics at the LHC, concentrating on the processes of the associated Higgs production.

Scopri di più »## Relaxed Inflation

The hierarchy problem of the Standard Model of particle physics might have a cosmological solution based on relaxion models, an idea recently put forward. In my talk I first review the basics of this mechanism and then discuss whether the relaxioncould also play the role of the inflaton.

Scopri di più »## The dirty side of the axion

Since the early 90’s it was understood that in order for the Peccei Quinn (PQ) mechanism to work the global U(1)_PQ had to be realized to an extremely high level of accuracy. In fact, even a tiny explicit breaking of the global PQ symmetry (e.g. via Planck-induced effective operators) would sizably contribute to the axion vacuum energy density and prevent the θ angle to relax to a value below the experimental upper bound |θ| < 10^-10. In this contribution, I will reproduce the standard argument and review possible mechanisms in order to protect the axion.

Scopri di più »## Constructing realistic GUTs of flavour

Recently, two SUSY GUTs of flavour have been proposed, based on SU(5) and SO(10) with non-Abelian flavour symmetry. They are reasonably complete, resolving many outstanding problems in GUT model building; as a result, they are rather involved. I am currently working on constructing the minimal and most predictive viable SO(10) model within this framework, with a focus on producing the correct masses and mixings for quarks and leptons. This may be combined with a Peccei-Quinn (PQ) symmetry to resolve the strong CP problem, giving a “flavoured PQ” GUT model. Within this framework, one might explore SUSY and/or axion phenomenology.

Scopri di più »## Route to TeV/cm, X-ray Wake Field Acceleration

Hitherto, the laser has been very successful to study atomic physics. The possibility to amplify lasers to extreme peak power offers a new paradigm unifying the atomic and subatomic worlds, to include Nuclear physics, High Energy Physics, Astrophysics and Cosmology. This application needs extreme intensities. At the moment we are experiencing a rush toward the 10 PW led by the 3-pillar ELI infrastructure along with Apollon in France and similar infrastructures in Russia, USA, China and Korea. One of the most intriguing applications is the possibility to produce extraordinary large gradients in the TeV/cm regime or 1000 times what is possible with LWA in the visible. Also we will discuss what the generation of GeV protons with numerous applications in proton therapy, short-lived isotope production, nuclear waste transmutation and the like.

Scopri di più »## The effect of hyperons and kaon on the structure of neutron stars

The relativistic mean-field (RMF) models either with higher order couplings or density-dependent couplings can be used to explain neutron stars properties with and without kaon or baryons. The nuclear interactions are described by the exchange of the sigma, omega and rho mesons. RMF parameterizations consistent with the recently studied constraints related to nuclear matter, pure neutron matter and symmetry energy were used to calculate the equations of state of star. The properties of nonrotating and rotating neutron stars are considered for a set of equations of state.

Scopri di più »## Winter Institute: Selected Topics on the Phenomenology of Present and Future Colliders

Aim of the workshop: This meeting aims at gathering theorists and experimentalists working in the Rome area in the field of collider physics. In an informal environment, we shall discuss several issues, which are relevant at present (SPS and LHC) and future accelerators. In particular, we shall debate the hunting for new physics with the NA62 detector, the coupling of the Higgs boson to gluons and top quarks, top-Higgs associated production and discuss the physics of future facilities, such as ILC and FCC, in both hadron-hadron and electron-positron modes.

Scopri di più »## The ubiquitous top quark

The top quark plays a central role in many LHC analyses that test the Standard Model and that search for new physics. I will review why this is so, and discuss in particular recent advances in how to describe the top quark production and decay processes precisely, including the spin of the top quark, and with possible new physics influences. Recent experimental results and theoretical advances will be reviewed, and an outlook given.

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