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Markus Cristinziani

Publications and source records attributed to Markus Cristinziani.

17 recordsLinked to original sources
arXiv2026

Hardware-efficient neural networks for FPGA-based radio triggering of extensive air showers

We present a hardware-efficient hybrid trigger for FPGA-based radio detection of extensive air showers. The hybrid design consists of a lightweight denoiser that cleans raw ADC traces and a compact classifier that operates on the denoised output, enabling robust near-threshold pulse detection in high-interference environments. Both neural networks are trained quantization-aware. Signals are generated from detector-folded CoREAS/CORSIKA simulations and embedded into measured noise to form a realistic benchmark. The trigger reaches an AUC of 0.992 while fitting comfortably within the resource budget of a Zynq-7000 Z-7020, with microsecond-scale latency and sub-watt power consumption. RTL validation confirms agreement between the fixed-point hardware and the quantized software model, demonstrating that neural denoising combined with classification provides reliable, low-cost radio triggering in noisy environments.

astro-ph.IM↗
arXiv2026

A dual-polarization whitened-template trigger for real-time radio detection of extensive air showers

Autonomous radio stations require a first-stage trigger that rejects measured background while preserving weak extensive-air-shower pulses under tight hardware constraints. We present a dual-polarization trigger based on a 16-sample whitened pulse template evaluated continuously on the orthogonal north-south and east-west channels of an Auger Engineering Radio Array station. The template is derived from detector-folded air-shower pulses and whitened using the covariance of measured background. Responses from both polarizations are combined within a fixed timing radius and compared with a calibrated threshold. On an independent test set, the trigger reaches an efficiency of 0.97, with a 95 percent confidence interval of 0.96 to 0.98, at a frame-equivalent candidate rate of 3.39 kHz. At the same operating point, an unwhitened dual-polarization template reaches 0.41 efficiency and an amplitude trigger reaches 0.16. Efficiency remains at least 0.94 in every populated signal-to-noise bin. Replay of 159.29 ms of continuous measured background yields a score-cluster rate of 6.64 kHz, below the 71.4 kHz capacity of the downstream module. The FPGA implementation accepts one dual-polarization sample per clock, closes timing at 200 MHz, and uses 2377 lookup tables, 5330 registers, and 32 digital signal-processing blocks. Register-transfer-level simulation agrees bit for bit with the reference implementation for 400 traces. These results show that background covariance, pulse morphology, and dual-polarization consistency can be combined in a compact real-time radio trigger.

astro-ph.IM↗
arXiv2026

Hybrid neural denoising for resource-efficient near- and sub-threshold radio triggering of extensive air showers

Autonomous radio self-triggering for extensive air showers must reject variable radio-frequency interference while preserving sensitivity to weak pulses and remaining compatible with station-level edge hardware. This work presents a hybrid neural trigger in which waveform recovery and signal classification are treated as a single deployment-constrained problem. A compact convolutional denoiser maps a noisy single-channel trace to a cleaned estimate of the air-shower pulse, which is then evaluated by a compact classifier. The method is tested with measured high-interference background traces and detector-folded air-shower pulses from the Pierre Auger Offline simulation chain, with signals concentrated in the near- and sub-threshold regime. Model selection and deployment are linked through hyperparameter optimisation, quantisation-aware training, fixed-point quantisation, hls4ml firmware export, high-level synthesis, and register-transfer-level validation. The denoiser alone turns a simple peak-envelope decision into an efficient weak-pulse trigger, showing that the cleaned waveform carries trigger-relevant information beyond a final classifier score. In the full denoiser-classifier chain, the hybrid trigger improves signal-background separation and efficiency at fixed false-positive rates: at a false-positive rate of 10^-4, it retains about 41% of held-out signal traces in the weak-signal benchmark, while the classical peak-envelope trigger retains none. The cleaned waveform preserves timing and peak-amplitude structure for station-level diagnostics, feature extraction, and selective readout. The firmware meets timing on representative FPGA targets with microsecond-scale latency and compact arithmetic-resource demand. These results establish hybrid neural denoising as a practical route toward radio-only triggering for weak and inclined air-shower signals in noisy environments.

astro-ph.IM↗
arXiv2025

Subatomic Heroes

Sharing the amazing achievements of the (particle) physics world with the general public is at the heart of the mission of the Subatomic Heroes, based at the University of Siegen, Germany. Originally this started out as an endeavor of theoretical particle physics, now we are steadily spreading out to cover and include more branches of physics and science. Our activities range from merging art with public physics lectures via marvelous artistic performances at the local theater, over dedicated events for high-school students, to our Subatomic Heroes channel on Instagram and TikTok where you may also find out when and where our famous "hadronic ice-cream" will be served next! So follow us on https://www.instagram.com/subatomic_heroes and https://www.tiktok.com/@subatomic_heroes.

physics.ed-ph↗
arXiv2020

The SHiP experiment at CERN

The current status of the proposed SHiP experiment at the CERN Beam Dump Facility is presented. SHiP is a general-purpose fixed-target experiment. The 400 GeV/$c$ proton beam extracted from the SPS will be dumped on a heavy target to integrate $2 \times 10^{20}$ protons on target in five years. The detector, based on a long vacuum tank followed by a spectrometer and particle identification detectors, will allow to probe a variety of models with light long-lived exotic particles and masses below ${\cal O}(10)$ GeV/$c^2$. The main focus will be the physics of the so-called hidden portals, i.e. the search for dark photons, light scalars and pseudo-scalars, and heavy neutrinos. The sensitivity to heavy neutrinos will allow to probe, in the mass range between the kaon and the charm meson mass, a coupling range for which baryogenesis and active neutrino masses could also be explained. A second dedicated detector will study neutrinos and explore light dark matter.

physics.ins-det↗
arXiv2019

Evidence for the production of three massive vector bosons with the ATLAS detector

The search for the production of three massive vector bosons in proton$-$proton collisions, performed using data at $\sqrt{s}$ = 13 TeV recorded with the ATLAS detector at the Large Hadron Collider in the years 2015$-$2017, corresponding to an integrated luminosity of $79.8$ fb$^{-1}$, is presented. Events with two same-sign leptons $\ell$ (electrons or muons) and at least two reconstructed jets are selected to search for $WWW \to \ell ν\ell νqq$. Events with three leptons without any same-flavour opposite-sign lepton pairs are used to search for $WWW \to \ell ν\ellν\ell ν$, while events with three leptons and at least one same-flavour opposite-sign lepton pair and one or more reconstructed jets are used to search for $WWZ \to \ell νqq \ell \ell$. Finally, events with four leptons are analysed to search for $WWZ \to \ell ν\ell ν\ell \ell$ and $WZZ \to qq \ell \ell \ell \ell$. Evidence for the joint production of three massive vector bosons is observed with a significance of 4.1 standard deviations, where the expectation is 3.1 standard deviations.

hep-ex↗
arXiv2019

Top-quark properties at ATLAS

Properties of the top-quark are presented, with emphasis on the most recent ATLAS measurements of the mass and $t\bar{t}$ spin correlations, obtained with proton-proton collision data collected at the Large Hadron Collider. Normalised differential distributions are used in both cases. For the extraction of the top-quark mass, $t\bar{t}+1$-jet single-lepton events are selected from the 20.2 fb$^{-1}$ 8 TeV dataset, and the unfolded distribution at parton level is compared with theoretical predictions to obtain $m_t^{\text{pole}} = 171.1^{+1.2}_{-1.1}$ GeV in the pole-mass scheme and $m_t(m_t) = 162.9^{+2.4}_{-1.6}$ GeV in the running-mass scheme. For the measurement of spin correlations in $t\bar{t}$ production, dilepton events are selected using 36.1 fb$^{-1}$ 13 TeV data. The azimuthal opening angle between the two leptons is measured inclusively and as a function of the invariant mass of the $t\bar{t}$ system. The observed degree of spin correlation is significantly higher than predicted by the generators used, but agrees well with the prediction of one of the fixed-order calculations.

hep-ex↗
arXiv2019

Recent diboson and multiboson results in ATLAS

Recent measurements of the associated production of two or three massive vector bosons in proton-proton collisions at the Large Hadron Collider, collected by the ATLAS detector at a centre-of-mass energy of $\sqrt{s} = 13$ TeV, are reported. The diboson analyses target the production and decay modes $WW\rightarrow eν_eμν_μ$, $WZ \rightarrow \ell^{\prime} ν\ell \ell\,(\ell = e, μ)$, $ZZ \rightarrow \ell\ellνν$, and the $4\ell$ final state. Fiducial inclusive cross sections are compared to state-of-the-art Standard Model calculations and several unfolded differential distributions are measured. In the $WZ$ channel, the helicities of the $W$ and $Z$ bosons are probed. Results are interpreted in terms of limits on anomalous gauge couplings in the framework of effective field theories. Finally, the first evidence for the production of three massive vector bosons ($WWW$, $WWZ$, $WZZ$) is presented.

hep-ex↗
arXiv2016

Top-quark physics at the Large Hadron Collider

This experimental review gives an overview of top-quark measurements performed by the two general purpose-detectors ATLAS and CMS during the first few years of running of the Large Hadron Collider. In the years 2010 - 2012 each experiment collected 5 fb$^{-1}$ of pp collision data at $\sqrt{s} = 7$ TeV and 20 fb$^{-1}$ at $\sqrt{s} = 8$ TeV, allowing detailed studies of top-quark production and decays, and measurements of the properties of the top quark with unprecedented precision.

hep-ex↗
arXiv2015

Top-quark production measurements

Recent measurements of top-quark production at hadron colliders are reviewed. The inclusive top-quark pair production is determined at four centre-of-mass energies at Tevatron and LHC with experimental uncertainties that are close to the uncertainties in theoretical calculations at next-to-next-to-leading order in QCD. Several differential measurements are performed and compared to simulation. Production of single top quarks is studied in the three different production channels. Top-quark pair production with neutral and charged vector bosons has been observed by the LHC experiments. Finally, production of additional heavy flavour quark pairs ($b\bar{b}$, $t\bar{t}$) is studied or searched for.

hep-ex↗
arXiv2013

Search for FCNC in top-quark events in ATLAS

Searches for flavor changing neutral current (FCNC) processes in top-quark production and decays by the ATLAS Collaboration are presented. Data collected from $pp$ collisions at the LHC at a centre-of-mass energy of 7 TeV during 2011, corresponding to an integrated luminosity of 2.05/fb, are used. In a first analysis single top-quarks produced via FCNC are searched for. Candidate events with a semileptonic top-quark decay signature are classified as signal or background-like events by using several kinematic variables as input to a neural network. No signal is observed in the neural network output distribution and a Bayesian upper limit is placed on the production cross-section. The observed upper limit is converted using a model-independent approach into upper limits on the coupling strengths k_{ugt}/Lambda < 6.9x10^{-3}/TeV and k_{cgt}/Lambda < 1.6x10^{-2}/TeV, where Lambda is the new physics scale, and on the branching fractions BF(t-->ug) < 5.7x10^{-5} and BF(t-->cg) < 2.7x10^{-4}. A second search is performed for top-quark pair-production events, with one top quark decaying through the t-->Zq FCNC (q=u,c) channel, and the other through the Standard Model dominant mode t-->Wb. Only the decays of the Z boson to charged leptons and leptonic W-boson decays are considered as signal. No evidence for an FCNC signal is found and thus an upper limit on the t-->Zq branching ratio of BF(t-->Zq)<0.73% is set at the 95% confidence level.

hep-ex↗
arXiv2011

Top physics with 0.70-1.08/fb of pp collisions with the ATLAS detector at the LHC

With data collected during the first half of 2011 pp run of the Large Hadron Collider at \surds = 7 TeV, a substantial data sample of high p_T triggers, 1.08/fb, has been collected by the ATLAS detector. Measurements of the production of top-quark pairs and single top-quarks in different channels, the top-quark mass, the top-quark pair charge asymmetry and spin correlations, and the W helicity fractions in top-quark decays are presented, as well as two searches for new physics effects involving top-quark pairs.

hep-ex↗
arXiv2009

Diamond Prototypes for the ATLAS SLHC Pixel Detector

Vertex detectors at future hadron colliders will need to cope with large particle fluences. Diamond is a particularly radiation hard material and exhibits further properties that makes it an attractive material for such detectors. Within the RD42 collaboration several chemical vapor deposition diamond samples are being studied in the form of strip and pixel detectors. While the quality of the poly-crystalline diamond samples is constantly increasing and the feasibility of producing wafers has been demonstrated, recently a single-crystal diamond pixel detector has been assembled and characterized in a 100 GeV particle beam at CERN. Results on performance, detection efficiency, spatial resolution and charge collection are reported here together with the latest radiation damage studies.

physics.ins-det↗
arXiv2008

Single top: prospects at LHC

Single top quark processes are interesting as direct probes of the $Wtb$ vertex, and are also an important background in searches of the Higgs boson and beyond the standard model physics. Both ATLAS and CMS have performed studies with simulated data to estimate the expected uncertainty on the production cross section measurements of the three single top processes ($t$-channel, s-channel, $tW$ production) in the first years of LHC operations. Results in the different channels and for the two experiments are reported.

hep-ex↗
arXiv2004

Charmless 2- and 3-body B decays and the angle alpha (phi2)

We present preliminary measurements of branching fractions and CP-asymmetry parameters in two- and three-body charmless hadronic B decays. The available data sample consists of 227 million Upsilon(4S) B decays collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at SLAC. We establish the observation of the decays B --> pi0 pi0 and B0 --> K0K0bar and constrain the CKM angle alpha with a full SU(2) isospin analysis in the B --> pi pi system and with a B0 --> pi+ pi- pi0 time-dependent Dalitz plot analysis.

hep-ex↗
arXiv2003

Search for Antimatter with the AMS Cosmic Ray Detector

Antimatter search results of the Alpha Magnetic Spectrometer (AMS) detector are presented. About 100 million triggers were collected in the 1998 precursor flight onboard space shuttle Discovery. This ten day mission exposed the detector on a 51.7 degrees orbit at an altitude around 350 km. Identification of charged cosmic rays is achieved by multiple energy loss and time-of-flight measurements. Bending inside the 0.15 T magnetic volume yields a measurement of the absolute value of the particle's rigidity. The supplemental knowledge of the sense of traversal identifies the sign of the charge. In the rigidity range 1 < R < 140 GV no antinucleus at any rigidity was detected, while 2.86 million helium and 165 thousand heavy nuclei were precisely measured. Hence, upper limits on the flux ratio antinuclei-to-nuclei are given. Different prior assumptions on the antimatter spectrum are considered and corresponding limits are given.

astro-ph↗