An ongoing experiment at PSI aims to determine the nuclear charge radius of $^{226}$Ra - needed by an experiment aiming at measuring atomic parity violation in a radium ion - by means of muonic atom spectroscopy. An intermediate test was performed with a $^{185,187}$Re target which is the last stable element whose nuclear charge radius has not been measured and shows similar nuclear structure...
The measurement of the hyperfine splitting (HFS) in muonic hydrogen at the ppm level by means of pulsed laser spectroscopy allows for extraction of the Zemach radius of the proton at the per mille level. This measurement, ongoing at the Paul Scherrer Institute, features a novel laser system to excite the HFS transition at 6.8 µm. To increase the transition probability, we will use a multi-pass...
Muonic hydrogen is a bound-state of a negative muon and a proton. Since a muon is 207 times heavier than an electron, the energy levels of muonic hydrogen are very sensitive to the nuclear structure. By means of laser spectroscopy, we are aiming at the measurement of the ground-state hyperfine splitting to extract the two-photon exchange contribution and the Zemach radius of the proton. This...
The magnetic (Zemach) radius of the proton can be determined from the ground-state hyperfine splitting (HFS) of muonic hydrogen (bound state between muon and proton). At PSI, Switzerland, we aim to measure this HFS at the ppm level by means of laser spectroscopy.
Since a high laser fluence at an unusual wavelength (6.8 micrometer) is required to excite the HFS, a novel laser system will be...
The ASACUSA collaboration, based at the AD of CERN aims to measure the ground state hyperfine structure of antihydrogen at a ppm level relative precision with a Rabi-type beam experiment [1]. For the same, a spectrometer line has been fully commissioned with studies on hydrogen, with a relative precision of 10$^{-9}$ [3]. This precision can be pushed further by the Ramsey method. Using the...
Recently, we have performed measurements on vacuum muonium formation at room and cryogenic temperatures at the the Paul Scherrer Institute. These measurements were conducted in the context of our efforts on the investigation of the gravitational interaction of antimatter and second-generation particles.
In our room temperature setup, the muon beam impinged on several targets such as zeolite...
The neutron's electric dipole moment is a probe sensitive to a broad range of CP violating physics beyond the standard model. However, a nonzero measurement remains elusive, despite successive measurements performed worldwide since 1951 improving in sensitivity by over 6 orders of magnitude. The most recent measurement took data from 2015-2016 at the ultracold neutron source at the Paul...
The n2EDM experiment hosted at the Paul Scherer Institute is seeking an improvement in the measurement of the neutron electric dipole moment (nEDM) by one order of magnitude. In order to achieve this goal, it is crucial to stabilize the magnetic fields inside the precession chamber, where neutrons are stored and Ramsey measurements are performed, down to 30 fT. This is especially challenging...
The search for the neutron electric dipole moment $d_n$, carried on by the n2EDM experiment at PSI could provide a better insight on the baryon asymmetry of the universe and/or new physics. The experimental goal to reach an order of magnitude higher sensitivity than previous efforts, means its systematic effects need to be better controlled. The appearance of a false $d_n$...
The n2EDM experiment being mounted at the Paul Scherrer Institute (PSI) will search for the neutron electric dipole moment (nEDM) with a baseline sensitivity of $1.1 \times 10^{-27} \mathit{e} \cdot \mathrm{cm}$. With the increase in statistical sensitivity, an accordingly better control of systematic effects is required. This study investigates the impact of Johnson-Nyquist noise originating...
Precision experiments in free neutron beta decay allow probing for physics beyond the Standard Model in a complementary manner to searches conducted at the LHC. NoMoS, the neutron decay products momentum spectrometer, aims to measure the momentum spectra of the charged decay products (electron and proton) in neutron beta decay with high precision. The spectrometer utilizes the concept of an...
The Belle II experiment at the SuperKEKB collider of KEK (Japan) will accumulate 50 ab$^{−1}$ of $e^+e^−$ collision data at an unprecedented instantaneous luminosity of $8\cdot 10^{35}$ cm$^{−2}$s$^{−1}$, about 40 times larger than its predecessor. The Belle II vertex detector plays a crucial role in the rich Belle II physics program, especially for time-dependent measurements. It consists of...
The SIDDHARTA-2 experiment aims to observe the energy shift and width of the kaonic deuterium ground state induced by the strong interaction via X-ray spectroscopy.
This measurement requires an improvement of the signal-to-noise ratio of at least a factor of ten compared to SIDDHARTA due to the very low kaonic deuterium X-ray yield. Therefore, three updates to the apparatus are implemented: a...
The LHCb experiment obtained outstanding results with the data collected during last two LHC data taking periods.
An upgrade of the LHCb detector will be installed aiming for a full detector readout at 40 MHz for Run 3 and 4. To cope with the increased luminosity, the current downstream tracking system will be replaced by the the Scintillating Fibre tracker.
The SciFi tracker uses 250µm...
Given the lack of smoking gun signatures that point to an energy scale to be explored, the landscape of post LHC Run2 motivates searching for new physics in a region that has not been well covered so far, i.e. physics involving new interactions much weaker than the electroweak scale.
Beam dump facilities of high intensity electron and proton beams can probe an unexplored parameter space of...
At the end of the Run 2 of the LHC the current Inner Detector (ID) of the ATLAS experiment will need to be replaced. A new all-silicon Inner Tracker (ITk) is currently being designed and given the increase in the simultaneous p-p collisions, its data-taking system will have to use radiation hard high-speed data links at 10 Gbps, for a total bandwidth of ~ 60 Tbps. In this talk, the concept of...
For operation at the High Luminosity LHC, the ATLAS detector will be upgraded in 2024-2026. Its Inner Tracker will be able to handle pile-up conditions of $\mu = 200$ which increases the digital data output significantly. A new optical to electrical conversion stage, the Optoboard system, needs to be designed in order to cope with this higher bandwidth requirement. In this talk I present the...
Cosmological and astrophysical observations point to the fact that the Standard Model (SM) of particle physics account for less than $5\%$ of the total energy density of our Universe. What remains is defined as dark energy and dark matter (DM). More specifically, indirect gravitational interactions measurements indicate that DM is five times more abundant than ordinary baryonic matter.
The...
A serially powered pixel detector is the baseline choice for the High-Luminosity upgrade of the inner tracker of the CMS experiment. A serial power distribution scheme requires less cable mass, improves power efficiency and is less susceptible to voltage transients than parallel powering. A prototype pixel-readout-chip has been designed for serial powering in 65nm-CMOS technology by the RD53...
Heavy neutrinos are predicted by numerous Beyond the Standard Model theories that provide answers to long-standing questions, such as the smallness of neutrino masses, matter-antimatter asymmetry and the nature of dark matter. In this talk, a status report on a search for a long-lived heavy neutrino decaying to three leptons is presented. This analysis focuses on the final state with one...
Statistical modelling is a key element for High-Energy Physics (HEP) analysis. Currently, most of this modelling is performed with the ROOT/RooFit toolkit which is written in C++ and poorly integrated with the scientific Python ecosystem. We present zfit, a new alternative to RooFit, written in pure Python. Built on top of TensorFlow (a modern, high level computing library for massive...
NA64 is a fixed target experiment at the CERN SPS aiming at a sensitive search for hidden sectors. The A′, called dark photon, could be generated in the reaction e−Z→e−ZA′ of 100 GeV electrons dumped against an active target which is followed by the prompt invisible decay A′→χχ. The experimental signature of this process would be a clean event with an isolated electron and large missing energy...
The ArgonCube Collaboration developed a novel design for Liquid Argon Time Projection Chambers (LAr TPCs), segmenting the total detector volume into a number of electrically and optically isolated TPCs sharing a common cryostat. For the charge-readout, a pixelated anode plane is employed, providing unambiguous 3D event reconstruction. To minimize inactive and dense material a new technology is...
As part of the R&D towards the ultimate dark matter observatory DARWIN, we conduct tests with novel silicon photomultipliers (SiPM) for vacuum ultra violet (VUV) light being a promising alternative to traditionally used photomultiplier tubes. In particular, we are operating a small-scale dual phase (liquid/gas) xenon time projection chamber (TPC) instrumented with VUV-sensitive SiPMs from...
The Advanced Wakefield Experiment (AWAKE) recently demonstrated that a 400 GeV/c proton bunch can drive high amplitude plasma wakefields. To effectively excite wakefields, the drive bunch length should be on the order of the plasma electron wavelength (typically < 3mm). However, available proton bunches at CERN have an rms length of 6-12 cm. To be still able to excite high-amplitude...
The concept of lepton universality is a cornerstone prediction of the Standard Model (SM). In the last few years, hints of lepton universality violation have been observed in both tree-level $b \to c l \nu$ and rare $b\to sll$ beauty decays. These results, combined with the tensions observed in angular and branching fraction measurements of rare semileptonic decays, point to a coherent pattern...
Semi-leptonic b-baryon decays provide a unique means to investigate Lepton Flavour Universality (LFU) at the LHCb experiment. Sensitivity to New Physics (NP) contributions could show up in the angular observables of the decay products. In this work, the decay amplitude of the process $\Lambda_{b}\to\Lambda_{c}\,l\,\nu$ as a function of the squared di-lepton invariant mass and lepton helicity...
Using data from the LHCb experiment at CERN, a search for the lepton-flavour-violating decay $B^{+} \to K^{+} \tau^{\pm} \mu^{\mp}$ is being performed. This decay is forbidden in the standard model (SM) of particle physics because it violates the lepton-flavour conservation. However, it is known that the SM cannot account for dark matter, dark energy, the strong $CP$ problem, the neutrino...
The family of decays mediated by $b \to s \ell^+ \ell^-$ transitions ($\ell = \mu, e$) provides a rich laboratory to search for effects of physics beyond the Standard Model. In recent years, LHCb has reported an anomalous behaviour in angular and branching fraction analyses of this decay, notably in one of the observables with reduced theoretical uncertainties, $P^{\prime}_{5}$. However, the...
Precision measurements of CP violating observables in beauty and charm hadron decays are powerful probes to search for physics effects beyond the Standard Model. The LHCb experiment is specifically designed to study these heavy hadron decays and is currently playing a major role in the field. One of its latest achievements is the first observation of CP violation in the charm sector. This talk...
A great step has been made recently in the field of CP violation in the charm sector, with the first observation of CP asymmetry by the LHCb collaboration (arXiv:1508.03054). A complementary approach to studying decay-rate asymmetries is investigating time-odd triple-product observables, which have the opposite dependence on the strong phase difference and thus complementary sensitivity to CP...
CP Violation (CPV) in the two-body decays of charm mesons was recently observed by the LHCb collaboration through the $\Delta A_{\mathrm{CP}}$ parameter. Current theoretical uncertainties cannot establish if this effect is due to physics beyond the Standard Model or not. Tests of CPV in the mixing or in the interference between mixing and decay might help clarify the picture. One way to probe...
We present a measurement of charm-mixing parameters in $D^0 \rightarrow K^0_S \pi^+ \pi^-$ decays with a model-independent method on data collected by the LHCb collaboration in 2011-2012 [arXiv:1903.03074], and the prospects for an improved analysis using the 2016-2018 data. The analysis measures the dimensionless parameter $x$ related to the mass difference between the mass eigenstates of the...
Direct and indirect CP violation is observed in particle decays. The latter usually includes oscillations between a neutral meson and its antiparticle. ATLAS measures this type of CP violation in the decay Bs -> J/psi + phi, with J/psi -> µ+µ- and phi -> K+K-, mainly because it is sensitive to higher order effects and therefore to deviations from known physics. Here the quantity of interest is...
The amplitudes describing the decays of neutral b-hadrons to charmless (quasi)-two-body final states receive contributions from b→u tree and b→d,s penguin topologies. This rich landscape of interfering amplitudes allows interesting CP-violation measurements to be performed. In the case of B decays to two vector particles, a full amplitude analysis also provides insight in the so-called...
A long standing tension between measurements of the CKM matrix element $V_{\rm ub}$ in inclusive and exclusive decays can be eased by introducing a small right-handed weak current.
By measuring the differential decay rate of the semileptonic decay $B^{+}\rightarrow\rho^{0} \mu^{+} \nu_{\mu}$, using data from the LHCb experiment, a bound on a possible right-handed weak current can be set. This...
In 2012, the ATLAS and CMS Collaborations announced the discovery of a new state with a mass around 125 GeV, compatible with the Standard Model Higgs boson.
A measurement of the Higgs-beauty quark coupling through the Higgs boson production associated with a Z or W boson in the lepton + beauty final state is presented. The analysis is based on 41.3/fb data from p-p collisions at 13 TeV...
Measuring the top quark Yukawa coupling is an important test of the standard model (SM) of particle physics and the production of a Higgs boson in association with top quarks (ttH) is the only channel that allows a direct measurement of this SM parameter. This talk will focus on the measurement of ttH where the Higgs boson decays to bottom quarks. The data were collected by the CMS experiment...
A search for direct top squark pair production is presented using Run 2 ATLAS data in final states containing at least three leptons and missing transverse momentum. Naturalness considerations suggest the third generation squark masses should be around the TeV scale and hence could be produced at LHC.
Models are considered where a pair of the heavier top squark mass eigenstates is produced,...
The measurement of low-mass $\rm e^+e^-$ pairs is a powerful tool to study the properties of the Quark-Gluon Plasma (QGP) created in ultra-relativistic heavy-ion collisions. Since such pairs do not interact strongly and are emitted during all stages of the collisions, they allow us to investigate the full time evolution and dynamics of the medium created.
Measurements in pp and p-Pb...
Despite the tremendous success of the Standard Model of particle physics, there remain several fundamental aspects of the Universe that are still not understood. One such is the violation of the symmetry of simultaneous charge exchange and parity inversion (CP), which allowed the early Universe to become more abundant in matter than in antimatter. For some 65 years the electric dipole moment...
The XENON project aims to directly detect Dark Matter, employing a dual-phase TPC (Time Projection Chamber) with a xenon target. Located at the Gran Sasso National Laboratory (LNGS), the XENON project began in 2006 with the prototype XENON10, followed by XENON100 in 2008. The third phase, XENON1T, has already achieved the highest sensitivity to the elastic scattering of nucleons and WIMPs...
The XENON1T dark matter experiment, located at the Laboratori Nazionali del Gran Sasso, currently holds the world-leading limit for direct detection of Weakly Interacting Massive Particles. Due to unprecedented low backgrounds, it also has discovery potential to dark matter in the form of dark photons and axion-like particles via absorption by bound electrons. Here I will present the latest...
The XENON1T experiment searches for Weakly Interacting Massive Particle (WIMP) dark matter candidate with a dual-phase xenon time projection chamber. Following the main result on spin-independent WIMP-nucleon scattering, the effort of the XENON collaboration is directed towards exploring other detection channels. For this purpose the signal reconstruction and data analysis need to be extended...
The current best estimate for the universe’s matter content consists of 84% dark matter, and the search for its composition remains of great interest. One possible candidate is a so far undetected ultra-low-mass axion. Various astronomical observations, and only one laboratory experiment, using ultra-cold neutrons, currently constrain the axion mass and its interaction strength in the allowed...
The SST-1M project, a 4 m-diameter Davies Cotton telescope with 9 degrees FoV and a 1296 pixels SiPM camera, is designed to meet the requirements of the next generation of ground based gamma-ray observatory CTA in the energy range above 3 TeV.
In this work, a special emphasis will be given to the commissioning results of the SST-1M telescope. The latest performance validation tests such as...
Since 2012 the IceCube detection of a diffuse population flux of astrophysical neutrinos confirmed the existence of population of sources emitting neutrinos above the 100 TeV energy scale, the nature of which remains still unknown. The sources of this diffuse neutrino high-energy excess need investigations with point-like source searches (time integrated and time dependent) and a strong...
This talk focus on the control and understanding of a gravitationally interacting elementary quantum system using the techniques of gravitational resonance spectroscopy (GRS) and ultracold neutrons (UCN). It offers a new way of looking at gravitation at short distances based on quantum interference.
In the past years, the qBOUNCE collaboration designed and built a new Ramsey-type experiment...
MAGIC and FACT investigate the very-high-energy (E>100GeV) gamma rays emitted by blazars, whose relativistic jets points towards the observer. Past observations have revealed that the blazar 1ES2344+51.4 can show strong flux variability and the spectral energy distribution shifts towards unusual high energies during flares. We report a flaring episode of 1ES2344+51.4 during August 2016, where...
A precise characterization of neutrino oscillation parameters is very important to search for physics beyond the standard model. T2K, located in Japan, is one of the leading long-baseline neutrino oscillation experiments. It measures a muon (anti-)neutrino flux, with energy peaked at ~0.6 GeV, produced at the J-PARC facility 295 kilometers east of the SuperK far detector. One of the most...
Supersymmetry and Grand Unified Theories predict several nucleon decay modes with lifetimes between $10^{28}$ and $10^{39}$ years. The Deep Underground Neutrino Experiment (DUNE) will be able to test many of the predicted decay modes for lifetimes up to $10^{35}$ years. DUNE's far detector will comprise four 10-kiloton Liquid Argon Time Projection Chambers (LAr TPCs) installed 1475 meters...
The discovery of neutrinoless double beta decay would establish neutrinos as Majorana fermions and imply a violation of lepton number conservation. The leading experiment based on $^{76}$Ge is GERDA, which operates a 36\,kg array of germanium detectors, enriched in $^{76}$Ge directly immersed in liquid argon. The argon acts a a coolant and active shield against background radiation due to its...
The DARWIN experiment is a next-generation dual-phase time projection chamber which will operate 50 tonnes of natural xenon and whose primary goal will be to explore the entire experimentally accessible parameter space for WIMPs. Besides its unprecedented sensitivity to WIMPs, such a large detector, with its low-energy threshold and ultra low background level, will also be sensitive to other...
DARk matter WImp search with liquid xenoN (DARWIN) will be a direct dark matter detection experiment using a multi-ton time projection chamber at its core. While DARWIN is designed to explore the entire experimentally accessible parameter space for WIMPs, the detector will also be sensitive to other rare interactions. One ambitious goal is the search for the neutrinoless double beta decay of...
MicroBooNE is the first of three liquid argon time projection chambers (LArTPCs) of the Short-Baseline Neutrino Program at Fermilab. Located on the Booster Neutrino Beamline, MicroBooNE has been collecting data since October 2015 to determine the source of the low-energy electromagnetic event excess previously reported by MiniBooNE and LSND. In addition, MicroBooNE is studying neutrino...
