The understanding of the Higgs coupling to fermions is among the main goals of the Run2 at the LHC. This talk will present the most recent results from LHC on this topic. Prospects for the full Run2 analyses and for CP measurements of the Hff vertex will be also discussed.
The measurement of Higgs boson production in association with a ttbar pair is essential to understand the top-quark couplings to the Higgs boson. This talks presents the analyses using Higgs boson decays to bbbar pairs, to two Z bosons, to other multi-lepton final states, and to a pair of photons, using pp collision data collected at 13 TeV.
The production of a Higgs boson in association with a pair of top quarks (ttH) is presented. In particular the final states with multileptons targeting the WW, ZZ and tautau decays of the Higgs boson, are reported. The data set analyzed corresponds 41.4 fb$^{-1}$ of pp collisions recorded by the CMS experiment in 2017. Machine learning and matrix element techniques are used to enhance the...
Testing the couplings of the Higgs boson to fermions is an important part to understand the origin of fermion masses. The talk presents cross section measurements in Higgs boson decays to two tau leptons, as well as a search for Higgs boson decays to two muons. Both analyses are based on pp collision data collected at 13 TeV.
In Run2 precise measurements of the Higgs production and its properties have been carried out using the Higgs decays to bosons. Recent results from the LHC will be discussed, including measurements of different Higgs production modes and differential cross section measurements.
The most precise measurements of Higgs boson cross sections, using the framework of simplified template cross sections, are obtained from a combination of the measurements performed in the different Higgs boson decay channels. This talk presents the combined measurements, as well as their interpretation.
The Higgs decay width can be constrained by exploiting interference effects of the $pp \to H \to \gamma\gamma$ signal with the $pp \to \gamma\gamma$ continuum background, which leads to a width-dependent shift of the Higgs mass peak. I review a study in which my collaborators and I investigate the reach of an analysis that determines the reference mass by measuring the di-photon final state at...
This talk will discuss the most recent results for the search of double Higgs non-resonant production at the LHC.
The sensitivity reached, which is still one order of magnitude above than the SM prediction, allows excluding already significant regions of the BSM phase space. Interpretation of searches results with a dedicated EFT approach will be showed. A particular focus will be also given...
At the LHC the dominant production channel for the Higgs-boson with two
jets is through gluon fusion, which is therefore also the dominant background for measuring the Higgs-boson production through weak boson fusion. To reduce the gluon fusion component WBF cuts require a large invariant mass of the dijet system. Thus the predictions become sensitive to a high energy logarithm. We present new...
Several direct searches for exotic Higgs decays, which will be a clear sign of BSM physics, are performed at the LHC (lepton flavour violation, long-lived particles, low-mass scalars, semi-invisible...). This talk will discuss the most recent searches performed at the LHC, the interpretation of the results and prospects for the full LHC Run2 analyses.
The searches for light pseudoscalar Higgs bosons pair produced from the decay of the 125 GeV Higgs boson and resulting in various final states (4mu, 4tau, 2mu2tau, 2b2tau) according to the mass of the light boson and searches for low mass scalar bosons below 125 GeV in decays to photon pairs will be summarised. The analyses are performed using data collected with the CMS experiment at the LHC...
Recent results on searches for Dark Matter are reported, including H->inv.
The presence of a non-baryonic dark matter component in the Universe is inferred from the observation of its gravitational interaction. If dark matter interacts weakly with the Standard Model it would be produced at the LHC, escaping the detector and leaving a large missing transverse momentum as their signature. The ATLAS detector has developed a broad and systematic search program for dark...
Evidence for the light-by-light scattering process, γγ → γγ, in ultraperipheral PbPb collisions at a centre-of-mass energy per nucleon pair of 5.02 TeV is reported. The analysis is conducted using a data sample corresponding to an integrated luminosity of 390 μb −1 recorded by the CMS experiment at the LHC. Light-by-light scattering processes are selected in events with two photons exclusively...
We present a novel framework to carry out global analyses of the Standard Model Effective Field Theory (SMEFT) at dimension-six: SMEFiT. The SMEFiT approach is based on the Monte Carlo replica method to derive a faithful estimate of the experimental and theoretical uncertainties and enables one to construct the probability distribution in the space of the SMEFT degrees of freedom.
As a proof...
Top quark production can probe physics beyond the SM in different ways. Some processes, and especially certain angular correlations, are sensitive to the existence of anomalous top quark couplings. In the SM, flavour-changing neutral currents (FCNC) are forbidden at tree level and are strongly suppressed in loop corrections. Several extensions of the SM incorporate significantly enhanced FCNC...
Many extensions to the Standard Model predicts new particles decaying into two bosons (W, Z, photon, or Higgs bosons) making these important signatures in the search for new physics. Searches for such resonant diboson resonances (including HH) have been performed in final states with different numbers of leptons, photons, jets and b-jets where new jet substructure techniques to disentangle the...
Many theories beyond the Standard Model predict new particles, including new gauge bosons or heavy Majorana or Dirac neutrinos, which decay to well isolated leptons. Searches for new physics models with these signatures, are performed using the ATLAS experiment at the LHC.
The sensitivity of beam dump experiments to heavy neutral leptons depends on the relative strength of their couplings to individual lepton flavours in the Standard Model. We study the impact of present neutrino oscillation data on these couplings in the minimal type I seesaw model and find that it significantly constrains the allowed heavy neutrino flavour mixing patterns. We estimate the...
Many theories beyond the Standard Model predict new phenomena which decay to light or heavy quarks. Such final states are of particular interest at the LHC since new phenomena produced in parton collisions are likely to produce final states with (at least) two partons. Various strategies are employed to probe high and low resonance masses. This talk will present the latest searches performed...
The talk will present the most recent results on inclusive searches for supersymmetric squarks (including direct stop and sbottom pair production) and gluinos at the LHC, possibly including R-parity violating scenarios and the description of special reconstruction techniques needed in these searches.
Supersymmetry (SUSY) is a theoretical favored extension of the standard model (SM) since it provides explanations for several issues. Models with general gauge mediation (GGM), have the additional benefit of naturally suppressing flavor violations in the SUSY sector. Many of those models predict the production of events with photons and significant missing transverse momentum. The results of a...
The talk presents results from searches for gaugino and slepton pair production at the LHC, possibly including R-Parity violating scenarios, and from searches for long-lived particles (excluding the ones from exotics Higgs decays), which can be detected through abnormal specific energy loss, appearing or disappearing tracks, displaced vertices, long time-of-flight or late calorimetric energy deposits.
We show that heavy ion collisions at the LHC provide a promising environment to search for signatures with displaced vertices in well-motivated New Physics scenarios. The lower instantaneous luminosity in heavy ion collisions allows to operate the LHC experiments with very loose triggers. For scenarios in which long-lived particles are produced in the decay of light particles, this can...
A major recent breakthrough in global fits of the quark and gluon structure of the proton has been the inclusion of a significant amount of precision LHC measurements. While these data sets provide important constraints, especially on the poorly-known gluon and antiquark PDFs, it is crucial to avoid any contamination from potential beyond the Standard Model (BSM) effects that could be present...
I present the theory of high energy hadron-lepton interactions in presence of a background which breaks Lorentz invariance (this parameterization of Lorentz violation is known in the literature as the Standard Model Extension). I apply this theory to the calculation of Lorentz violating effects in DIS and present the expected bounds that can be obtained by sidereal time analyses of existing...
Leptoquarks are predicted by many new physics theories to describe the similarities between the lepton and quark sectors of the Standard Model and offer an attractive potential explanation for the lepton flavour anomalies observed at flavour factories. The ATLAS experiment has a broad program of direct searches for leptoquarks, coupling to the first-, second- or third-generation particles....
High-precision HERA data corresponding to a luminosity of around
1 fb$^{-1}$ have been used in the framework of $eeqq$ contact
interactions (CI) to set limits on possible high-energy contributions
beyond the Standard Model to electron--quark scattering. Measurements
of the inclusive deep inelastic cross sections in neutral and charged
current $ep$ scattering were considered. The analysis of...
The prospects of the proposed Large Hadron electron Collider (LHeC) in the
search for heavy neutral scalar particles are discussed.
A minimal model is considered with one additional complex scalar singlet that interacts with the Standard Model (SM) via mixing with the Higgs doublet, giving rise to a SM-like Higgs boson h1 and a heavy scalar particle h2.
Both scalar particles are produced via...
The Large Hadron Collider (LHC) has been successfully delivering proton-proton collision data at the unprecedented center of mass energy of 13 TeV. An upgrade is planned to increase the instantaneous luminosity delivered by LHC in what is called HL-LHC, aiming to deliver a total of about 3000/fb of data to the ATLAS detector. To cope with the expected data-taking conditions ATLAS is planning...
The type II seesaw mechanism is an attractive way to generate the observed light neutrino masses. It postulates a SU(2)$_\mathrm{L}$-triplet scalar field, which develops an induced vacuum expectation value after electroweak symmetry breaking, giving masses to the neutrinos via its couplings to the lepton SU(2)$_\mathrm{L}$-doublets. When the components of the triplet field have masses around...
The production of a light charged Higgs boson at the future Large Hadron electron Collider (LHeC) and Future Circular Collider in the mode hadron-electron (FCC-he) is studied, the main process e^− p \to \nu_e H^− q is considered, taking in account the decay channels H^− \to b \bar{c} and H^− \to \tau \nu_{\tau} in the final state. We analyze these processes in the framework of the 2-Higgs...
