The FCC-ee is a proposed future e$^+$e$^-$ collider capable of producing all SM particles in large quantities and clean experimental conditions. Up to four experiments can detect the collision products, with IDEA being one of the proposed detector concepts at FCC-ee. IDEA needs to fulfil requirements similar to experiments at other proposed lepton colliders such as reliable particle...
For the High-Luminosity phase of the LHC (HL-LHC) the ATLAS detector will undergo a series of upgrades to cope with the increased number of proton interactions and harsher radiation environment. One of the key projects in this suite of upgrades is the ATLAS Inner Tracker (ITk) and its pixel detector, which will have unprecedented granularity and number of channels, that require extreme...
The LEMING experiment at the Paul Scherrer institute aims to measure the free fall of muonium (M $= \mu^+ + e^-$), an exotic atom consisting purely of leptons. Measuring the free fall of M would be the first test of the weak equivalence principle using elementary antimatter of the second generation and using a system without large hadronic contributions to its mass.
Such a direct measurement...
The first search for the Z boson decay to $\tau\tau\mu\mu$ is presented. The data analyzed were collected by the CMS experiment at the CERN LHC in proton-proton collisions at a center-of-mass energy of 13 TeV and correspond to an integrated luminosity of 138 $\mathrm {fb^{−1}}$. Targeting tau lepton decays to muons and the corresponding
neutrinos, events with two pairs of oppositely charged...
Introduction to PIONEER, a next generation rare pion decay experiment located at PSI.
The LEMING (LEptons in Muonium INteracting with Gravity) experiment aims to measure the gravitational acceleration of Muonium (M = e$^−$ + $\mu^+$ ) in the gravitational field of the earth. An essential part of this experiment is the reliable detection of M’s decay products, i.e. e$^+$ and e$^−$, at temperatures below 1$\,$K. The electron, referred to as atomic electron, can be accelerated to...
Beyond the minimal kinetically-mixed dark photon scenarios predicting fully visible and fully invisible mediator decays, next-to-minimal theories have been considered as compelling frameworks for thermal dark matter and some low-energy anomalies, as the muon g-2.
This talk will showcase the potential of the NA64 experiment in the exploration of rich dark sectors in which the dark photon is...
NA64 is a fixed-target frontier experiment running at the CERN SPS. NA64 searches for possible candidates of mediators between the dark sector and the standard model by looking for missing energy events in an active beam dump. After resuming data taking in 2021, NA64 has tripled its statistics, allowing us to set leading constraints to dark sector mediators in the light dark matter parameter...
We present performance tests of the ATLAS Phase-II Outer Barrel Pixel detector services chains. The Phase-II pixel upgrade is part of the ITk HL-LHC upgrades to be installed later in this decade. After successful completion of the design phase, the final components are undergoing production and integration testing. A full data transmission chain is set up at the University of Bern for ITk that...
We present the first observation of $\tau$ lepton pair production in ultraperipheral nucleus-nucleus collisions. The measurement is based on a data sample collected by the CMS experiment at a per nucleon center-of-mass energy of $5.02~\mathrm{TeV}$, and corresponding to an integrated luminosity of $404~\mu\mathrm{b}^{-1}$. The $\gamma\gamma\to\tau^{+}\tau^{-}$ production is observed with a...
In the light of the current hints for new scalars at the LHC at 95 GeV and 151 GeV, I present an analysis of low mass resonances decaying into W bosons. Recasting and combining the SM Higgs analyses of ATLAS and CMS, our results give further support to the existance of such new Higgs bosons.
The work is based on the paper: e-Print:2302.07276 [hep-ph]
I discuss the two-Higgs doublet model extended by a complex singlet and an additional U(1) gauge group (N2HDM-U(1)) and compare it to the standard two-Higgs doublet model with Z2 symmetries (N2HDM-Z2). We show that the N2HDM-U(1) is more predictive as it has one less free parameter, is CP conserving, and involves only spontaneous symmetry breaking. We then examine the phenomenological...
NA62 is a fixed-target experiment at the CERN SPS dedicated to measurements of rare kaon decays. It is approved to take data until CERN long shutdown 3, with the primary goal to collect the order of 100 candidates $K^+ \rightarrow \pi^+ \nu \bar{\nu}$ events and to measure the corresponding branching ratio with the precision of the order of 10%. The experiment resumed data taking in 2021 after...
An electric dipole moment (EDM) of a fundamental particle would violate time (T) and parity (P) symmetry and by the virtue of the CPT theorem also the combined symmetry of charge conjugation and parity inversion (CP). Searches for EDM are generally considered highly sensitive probes for new physics and might shed light on still unresolved questions in particle physics and cosmology like the...
The SoLAr detector concept, aims to extend the sensitivities of LArTPC detectors to the MeV energy range, and expands their physics reach to observe solar neutrinos and potentially supernovae neutrinos.
The core concept is centered around an integrated charge-light readout plane, consisting of pixel pads for charge collection and VUV SiPMs for direct de- tection of LAr scintillation light....
The FCC-ee project takes a step forward towards the discovery of new physical phenomena beyond the frontier of the standard model, by aiming at unprecedented center of mass energies and luminosities in a double-ring lepton collider. In order to explore potential improvements to the current beam optics design, this work looks at the use of combined function magnets for the main dipoles and...
