10 years after the discovery of the Higgs boson, the LHC is gearing up for two more decades of operations, during which it will evolve into a precision machine. Amidst a shortage of particle discoveries, precision will allow the implementation of new strategies to search for new physics, aiming for non-resonant signals.
This is the main motivation underlying the huge development in EFT...
Improving the sensitivity to CP-violation in the Higgs sector is one of the pillars of the precision Higgs programme at the Large Hadron Collider. I will present a simple method that allows CP-sensitive observables to be directly constructed from the output of neural networks. In this talk, I will show that these observables have improved sensitivity to CP-violating effects in the production...
We show that only 10 (17) CP-odd operators of the SMEFT give the leading, i.e. least suppressed by the new physics scale, CP-violating contributions once we assume that all fermions are massless but the top (and bottom) quark(s). We start with a short review of previous analyses focusing on operators of our reduced basis and list different observables probing their CP violating effects by...
Vector-boson scattering (VBS) processes probe the non-Abelian gauge structure of the electroweak sector of the Standard Model, and provide a unique sensitivity to potential kinematic anomalies arising from the inclusion of SMEFT operators. In this talk, we report on the most recent VBS measurements performed at CMS with the full LHC Run 2 data, and on the corresponding constraints on the...
One of the usual assumptions in Effective Field Theories (EFTs) is to truncate the expansion with the dimension-6 operators. I discuss the relevance of including operators of dimension-8 in an EFT for the 2 Higgs Doublet Model (2HDM). I present the matching between EFT and 2HDM up to dimension 8, written in terms of well-known bases, considering a generally CP-violating 2HDM. Using the...
Lepton Flavor Violating (LFV) observables such as $\mu\to e\gamma$, $\mu\to 3e$ and $\mu N \to eN$ are among the best probes for new physics at the TeV scale. In the near future the bounds on these observables will improve by many orders of magnitude. In this work we use the SM EFT to understand the impact of these measurements. The precision reach on the measurement of these processes is such...
Precision measurements in nuclear and neutron beta decay will be reviewed and analyzed both within the Standard Model and looking for new physics. Using an EFT description I will discuss the interplay between the different experiments and which ones are the most sensitive and promising.
Effective field theories (EFTs) are a powerful tool for the exploration of potential new physics in a model-independent way. At a time when there is a lack of clarity on how to extend the Standard Model, the Standard Model effective field theory (SMEFT) and related EFTs have been receiving an increasing amount of attention. For example, the number of SMEFT operators, up to high mass...
I will describe a procedure for the automated building of simplified models starting from effective operators, and how this procedure was used to derive a large class of novel and historical neutrino-mass models using an open-source Python library. I will discuss some details of the algorithm as well as the database of neutrino-mass models that it has produced. I will conclude with possible...
In recent years a great deal of work has been put into the framework that is the Standard Model Effective Field Theory. One loop calculations are currently being used to increase the precision of SMEFT predictions. Within these predictions, three Electroweak input parameters need to be decided on, with the historically accepted choice in the SM being the set {Alpha_EW, G_f, MZ}. Our work...
I will report on recent developments concerning the Python package smelli, which implements a global likelihood function in the space of dimension-six Wilson coefficients in the Standard Model Effective Field Theory and the Weak Effective Theory above and below the electroweak scale, respectively. This likelihood can serve as a basis either for model-independent fits or for testing dynamical models.
There is an increased effort to perform global fits of current experimental results in order to find signs of New Physics. The Standard Model Effective Field Theory has become the leading framework for these efforts thanks to offering a theoretically consistent and mostly model-independent way to parameterize deviations from the SM. More recent studies aim at interpreting the results of such...
We classify the SMEFT operators into the so-called "J-basis" that are responsible for generating local amplitude of the specific scattering channel with definite angular momenta and gauge quantum numbers. In this sense, the J-basis operators can be viewed as originating from integrating out a heavy field with the corresponding spin and gauge quantum numbers. Such a classification can lead to a...
We derive the finite one-loop counterterm required to restore the Ward Identities broken by the regularization scheme in chiral gauge theories. Our result is an analytic expression applicable to a wide class of regularizations satisfying a few general properties. We adopt the background field method, which ensures background gauge invariance in the quantized theory, and focus on renormalizable...
Hamiltonian truncation is a non-perturbative numerical method for calculating observables of a quantum field theory. In this talk, I will show how to treat Hamiltonian truncation systematically using effective field theory methodology. The starting point for this method is to truncate the interacting Hamiltonian to a finite-dimensional space of states below some energy cutoff Emax. The...
Moments of the leptonic angular distribution in the Drell-Yan process have recently been shown to be sensitive probes of a specific class of dimension-8, four-fermion operators in the Standard Model Effective Field Theory, involving a pair of quarks and leptons. The same operators are also subject to positivity bounds, when requiring the associated (unknown) UV completion to obey basic...
In the quest for new physics (NP), due to the lack of any direct evidence, the framework of Effective field theory (EFT) becomes an indirect and consistent way to parametrise NP effects in terms of higher dimension operators. Among the observables with the potential to account for NP signatures, Electroweak Precision Observables (EWPO) and those from Higgs productions and decays play an...
High-energy lepton colliders with a centre-of-mass energy in the multi-TeV range are currently considered among the most challenging and far-reaching future accelerator projects. We observe that starting from collider energies of a few TeV, electroweak (EW) vector boson fusion/scattering (VBF) at lepton colliders becomes the dominant production mode for all Standard Model processes relevant to...
Recent measurements at the Large Hadron Collider allow for a robust and precise characterisation of the electro-weak interactions of the top quark. We present the results of a global analysis at next-to-leading order precision including LHC, LEP/SLD and Tevatron data in the framework of the Standard Model Effective Field Theory. We include a careful analysis of the impact of correlations among...
