Production of the leptophilic Z' boson at the future colliders has been proposed as one of the benchmark BSM scenarios for the Briefing Book being prepared for the 2026 update of the European Strategy for Particle Physics. Presented in this contributions are results on the sensitivity of the ILC experiment to $L_e - L_\mu$ scenario. Expected cross section limits as a function of the Z' boson...
In this talk, we discuss the possibility of detecting new SM-neutral vector bosons ($Z'$) that couple exclusively to leptons at the FCC-ee. Focusing on the $Z'$ production with a radiated photon, we show that the FCC-ee can significantly extend the unprobed parameter space by increasing the exclusion in the coupling by one to two orders of magnitude in the kinematically allowed mass range...
Several new physics scenarios still allow for novel scalar states with masses below a few hundred GeV. In this talk, I will give a short overview on such scenarios and comment on some recent search studies at Higgs factories.
The physics program of the Higgs factory will focus on measurements of the 125 GeV Higgs boson, with the Higgs-strahlung process being the dominant production channel at 250 GeV. However, similar production of exotic light scalars, in a scalar-strahlug process, is still not excluded by the existing experimental data, provided their coupling to the SM gauge bosons is sufficiently suppressed....
The direct pair-production of the superpartner of the $\tau$-lepton, the $\widetilde{\tau}$,
is one
of the most interesting channels to search for SUSY in:
the $\widetilde{\tau}$ is
likely to be the lightest of the scalar leptons,
and is one of the most experimentally challennging ones.
The current model-independent $\widetilde{\tau}$ limits come from LEP,
while limits obtained at the...
The existence of Higgs-like scalars, which could be produced at
electron-positron collider in association with a Z boson, is predicted
by many BSM models and, assuming a small
coupling to the Z boson, still not excluded by experimental data.
Prospects for discovering such an scalar at future Higgs
factories have been studied by different methods.
The most model-independent one is based...
A central goal of future collider experiments is to probe the shape of the Higgs potential. This requires access to trilinear scalar couplings, and in particular the self-coupling of the detected Higgs boson. While this coupling is fixed in the Standard Model (SM), it can be significantly modified in many Beyond the Standard Model (BSM) scenarios, which are often linked to solutions of open...
In the talk the parameter determination of the fundamental parameters in the supersymmetric MSSM is discussed and in particular its relevance wrt to dark matter determination. The importance of polarized beams and threshold scans is critically analyzed. Precision requirements of masses, cross sections and asymmetries has been worked out. The impact of virtual particles masses has been analyzed...
In a class of theories, dark matter is explained by postulating the existence of a dark sector',
which interacts gravitationally with ordinary matter. If this dark sector contains a U(1) symmetry,
and a correspondingdark' photon ($A_{D}$) , it is natural to expect that this particle kineticly mix
with the ordinary photon, and hence become a `portal' through which the dark sector can be...
Future e$^+$e$^-$ colliders provide a unique opportunity for long-lived particle (LLP) searches. We present a full simulation study of LLP searches using the International Large Detector (ILD), where a gaseous time projection chamber as the main tracking device provides excellent prospects for LLP searches. Signatures of displaced vertices and kinked tracks are explored. We study challenging...
We investigate the possibility of probing an extra Higgs boson at future linear $e^+ e^-$ colliders. We consider the $e^+e^- \to H\nu \bar\nu$ production process, followed by $H \to W^+W^-$ decay, where $H$ is the extra CP-even Higgs boson of the general two Higgs doublet model. This process is governed by the CP-even Higgs mixing angle, $\cos\gamma$, offering direct access to this parameter....
Due to the large QCD background, tt spectroscopy is poorly doing at LHC with the exception of a toponium candidate first observed with high statistical significance by CMS. Our previous work predicts a contribution at almost the same mass from a Kaluza Klein graviton T376. For heavy scalars, following ATLAS and CMS, we describe how the top loop contribution to the gluon-gluon fusion mechanisms...
Strong-field quantum electrodynamics offers a unique window into non-perturbative phenomena such as vacuum pair production, where electron-positron pairs emerge from intense electromagnetic fields. The LUXE experiment at DESY will soon probe this regime using collisions between a high-intensity laser and the 16.5 GeV electron beam of the European XFEL. Future accelerator infrastructures, such...
https://arxiv.org/pdf/2504.03841
The International Linear Collider (ILC), with its technologically mature accelerator and detector designs and well-understood physics program, represents a realistic candidate for a future Higgs factory. Its staged energy program, the use of polarized beams, and the capability to reach center-of-mass energies up to 1 TeV offer unique sensitivity to deviations from Standard Model predictions in...
