COMETA workshop on BSM in Multiboson Processes

Contribution List

4. Exotic h → Za Higgs decays into τ leptons

Camila Ramos

New techniques and probes

Exotic Higgs decays are among the most promising areas to be explored at the High-Luminosity LHC, given the unprecedentedly large amount $(\sim 3 \times 10^8)$ of 125 GeV Higgs bosons that will be produced. In this context, we propose a new search channel for which the Higgs boson decays to a (leptonically decaying) $Z$ boson and a light BSM pseudoscalar $a$, which subsequently decays to a...

3. Multi boson processes in EFTs from on-shell amplitude techniques

Michal Jakub Ryczkowski (Università di Padova and INFN, Sezione di Padova)

Multi-boson processes are essential for probing the nature and dynamics of the Higgs boson and its interactions with massive vector bosons.

In this talk, we apply on-shell amplitude techniques to study multi-boson processes involving massive vectors and scalars. We construct the relevant kinematic structures, match the results to both the Higgs Effective Field Theory (HEFT) and the Standard...

5. New Bosons from a Deformed Massless-Up-Quark Solution to the Strong CP Problem: Is the Axion Hiding in Plain Sight?

Luca Di Luzio

Model building

In a recent paper, Murayama proposed a GeV-scale axion scenario in which the up-quark mass arises dynamically from the QCD chiral condensate, which also spontaneously breaks a Peccei-Quinn symmetry. If correct, the QCD axion may already be hidden among the known pseudoscalar resonances in the 1-2 GeV region, accompanied by a scalar partner predicted by the same framework. The proposal,...

8. Novel Background for BSM searches in VBS in the scalar channel

Sofie Martins (University of Graz)

Precision

BSM in the process $VV\rightarrow H^* \rightarrow VV$ can arise in two ways: As an effective extension of a composite Higgs at low energies or by a deviation hinting at a close-by resonance at high energies. It is thus necessary to control the standard model in these regions to high precision. We present novel standard model backgrounds, alongside lattice estimates for them, which arise from a...

7. Probing Z' Models at Future Colliders

Barbara Anna Erdelyi (Università degli Studi di Padova and INFN Sezione di Padova)

New techniques and probes

Several models of grand unification predict the existence of an additional gauged $U(1)_D$ symmetry, which gives rise to a new heavy neutral gauge boson $Z'$ at the TeV scale. In general, the Standard Model particles may be charged under this new symmetry, with gauge coupling $g_D$, and the $Z'$ can exhibit a kinetic mixing $\epsilon$ with the hypercharge gauge boson as well. Future...

9. Recovering LHC sensitivity to GGM in photon-deficient regions with boosted objects and machine learning

Mr Debabrata Sahoo (Institute of Physics Bhubaneswar)

Model building

We propose a comprehensive search strategy for gluinos in the framework of General Gauge Mediation (GGM) at the high-luminosity LHC. Conventional GMSB searches at the LHC rely on a final state with multiple hard photons originating from the decay of a bino-higgsino-mixed NLSP into a gravitino LSP. As we have shown in our previous work, this strategy loses sensitivity over a significant portion...

6. Sensitivity to top-quark couplings in diboson production at lepton colliders

Eugenia Celada

Effective Field Theory

We show results for the next-to-leading order electroweak corrections to $e^+e^− \to W^+W^−$ from dimension-six two-fermion top-quark operators in the SMEFT. We discuss the analytical computation and show results for future electron–positron colliders,focusing on the proposed LEP3 and FCC-ee that will operate at centre of mass energies below the $t\bar t$ production threshold. We compare the...