The COmpact DEtector for EXotics at LHCb (CODEX-b) is a particle physics detector dedicated to displaced decays-in-flight of exotic long-lived particles (LLPs), compelling signatures of dark or hidden sectors Beyond the Standard Model, which arise in theories containing a hierarchy of scales and/or small parameters. CODEX-b is planned to be installed near the LHCb interaction point and makes...
High precision Higgs coupling measurements are mandatory to establish the exact nature of the electroweak symmetry breaking mechanism and to pin down possible effects of BSM physics. Higgs coupling measurements are generally done in the kappa framework, which is based on inclusive production and decay rates, it is therefore blind to any tension in differential distributions. It also assumes...
Di-Higgs production at the LHC associated with missing transverse energy is explored in the context of simplified models that generically parameterize a large class of models with heavy scalars and dark matter candidates. Our aim is to figure out the improvement capability of machine-learning tools over traditional cut-based analyses. In particular, boosted decision trees and neural networks...
We investigate di-Higgs production at the (HL-)LHC in the Two Higgs Doublet Model (2HDM). We discuss the impact of higher-order corrections and interference effects. We demonstrate the problems applying experimental limits to realistic UV-complete models
Due to the pseudo-scalar nature of the axion-like particle (ALP), the CP-conserving production of two Higgs bosons via the ALP necessarily involves an additional $Z$ or $\gamma$ boson. We examine the existing constraints from di-Higgs searches at Run 2 of the LHC and find that, despite the presence of extra objects in the final state, these searches are sensitive to ALP couplings. We compare...
After more than three years of upgrade and maintenance work, a new period of LHC data taking started in 2022 with a record collision energy of 13.6 TeV. This presentation will be focused on top quark and standard model measurements performed with 2022 data collected by the CMS experiment at this new energy regime. The measurements of single top tW inclusive and differential cross sections and...
I will summarize some of the recent activities of the Effective Field Theory (EFT) Working Group, with special emphasis on those in area 5 (Benchmark Scenarios from UV Models). I also will review the current status of automated tools for EFT matching, highlighting their potential and applications to the field.
Emerging jets are jets with multiple displaced tracks, which originate from the decay of long-lived bound states of a strongly interacting dark sector. In this talk I will summarize our attempts to "validate" the CMS emerging jet search, showing that we are able to reproduce, within reasonable accuracy, the limits obtained by the CMS collaboration in their benchmark model.
The derived...
Lepton flavour universality is conserved in the Standard Model, however still
nowadays, many experimental measurements of lepton flavor universality ratios
exhibit a non-negligible tension with respect the theory predictions, which has a
notable low uncertainty. This makes LFU measurements a gateway for the search of
new physics which must be investigated to solve this tension. The LHCb...
Long-lived particles (LLPs) are predicted in many well-motivated theories of BSM physics, and naturally arise from the presence and breaking of symmetries, which can be motivated by cosmology and the nature of dark matter, neutrino masses, as well as solutions to the hierarchy problem. If these long-lived particles (LLPs) were to be produced at the LHC, they could decay far from the...
The search for weakly interacting particles is one of the main objectives of the high luminosity LHC. In the Minimal Supersymmetric Extension of the Standard Model (MSSM), these particles include the lightest neutralino, which is a good Dark Matter (DM) candidate and whose relic density may be fixed to realistic values through its co-annihilation with the second lightest neutralino and...
Differential cross sections for top-quark pair production, inclusively and in association with jets, are measured in pp collisions at a centre-of-mass energy of 13 TeV with the ATLAS detector at the LHC using an integrated luminosity of 140 fb−1. The events are selected with one charged lepton (electron or muon) and at least four jets. The differential cross sections are presented at particle...
We have studied the phenomenological implications of multiple Higgs boson production from longitudinal vector boson scattering in the context of effective field theories. We found compact representations for effective tree-level amplitudes with up to four final state Higgs bosons. Total cross sections are then computed for scenarios relevant at the LHC in which we found the general Higgs...
A measurement of the WW boson pair production cross section in proton-proton collisions at sqrt(s) = 13.6 TeV is presented. The data used in this study are collected with the CMS detector at the CERN LHC in 2022, and correspond to an integrated luminosity of 35fb-1. The WW candidate events are selected by requiring one electron and one muon of opposite charge. A sequence of requirements on...
New massive scalar or pseudo-scalar states with strong couplings to the top quark are predicted in numerous extensions of the Standard Model. These include models with an extended Higgs sector, such as Two-Higgs-Doublet Models (2HDMs). In this talk, two recent searches for new scalar and pseudo-scalar particles with couplings to the top quark using the full LHC Run-2 dataset are presented....
We report the results of a search for symmetric particle pair production in $138~fb^{-1}$ of pp collisions at $\sqrt{s} = 13$ TeV collected by the CMS detector during the LHC RunII data taking period. We use a sample of events with two oppositely charged leptons (electrons or muons) and large missing transverse momentum to perform the search. The results are interpreted in terms of several...
Although Effective Field Theories (EFTs) can be used to describe physics up to a given energy scale, the question of what lies beneath the EFT subsides, and eventually, a connection between the UltraViolet (UV) Theory and the EFT becomes necessary. In the last decade, the description of the electroweak sector has been addressed by two EFTs: the Standard Model Effective Field Theory (SMEFT) and...
The study of exclusive processes in lepton-hadron and in ultra-peripheral hadron-hadron collisions provides information on the three-dimensional distribution of quarks and gluons as a function of their longitudinal momentum and transverse position inside the hadron, where the longitudinal direction corresponds to the direction of the probe used to investigate the hadron. This will be...
