A5021824433- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Radiation Detection and Scintillator Technologies
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Neutrino Physics Research
- Medical Imaging Techniques and Applications
- Nuclear Physics and Applications
- CCD and CMOS Imaging Sensors
- Nuclear physics research studies
- Radio Astronomy Observations and Technology
- Atmospheric Ozone and Climate
- Muon and positron interactions and applications
- Gamma-ray bursts and supernovae
- X-ray Spectroscopy and Fluorescence Analysis
- Comparative Literary Analysis and Criticism
- Photocathodes and Microchannel Plates
- Solar and Space Plasma Dynamics
- Geophysical and Geoelectrical Methods
- Nuclear reactor physics and engineering
- Radiation Therapy and Dosimetry
- Pulsars and Gravitational Waves Research
LIP - Laboratory of Instrumentation and Experimental Particle Physics
2016-2025
University of Coimbra
2015-2024
University of Lisbon
2015-2020
Centro Brasileiro de Pesquisas Físicas
2017
Universidade Estadual de Campinas (UNICAMP)
2017
Universidade Federal de São Carlos
2017
Universidade de São Paulo
2017
Slovak Academy of Sciences
2016
Pierre Auger Observatory
2016
Institute of Physics Rosario
2016
Abstract A new analysis of the data set from Pierre Auger Observatory provides evidence for anisotropy in arrival directions ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative excess arrivals strong, nearby sources. The consist 5514 events above with zenith angles up to 80° recorded before 2017 April 30. Sky models have been created two distinct populations extragalactic gamma-ray emitters: active galactic nuclei second catalog hard Fermi -LAT sources (2FHL)...
Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on absolute calibration, and apply it events with primary 6–16 EeV (ECM=110–170 TeV), whose longitudinal development lateral distribution were simultaneously measured by Pierre Auger Observatory. The average shower is 1.33±0.16 (1.61±0.21) times larger than predicted using leading LHC-tuned EPOS-LHC...
We report a measurement of the energy spectrum cosmic rays for energies above 2.5×1018 eV based on 215,030 events recorded with zenith angles below 60°. A key feature work is that estimates are independent assumptions about unknown hadronic physics or primary mass composition. The most precise made hitherto accumulated exposure being so large measurements flux dominated by systematic uncertainties except at 5×1019 eV. principal conclusions (1) flattening near 5×1018 eV, so-called "ankle,"...
Abstract SND@LHC is a compact and stand-alone experiment designed to perform measurements with neutrinos produced at the LHC in pseudo-rapidity region of 7.2 < η 8.4. The located 480 m downstream ATLAS interaction point, TI18 tunnel. detector composed hybrid system based on an 830 kg target made tungsten plates, interleaved emulsion electronic trackers, also acting as electromagnetic calorimeter, followed by hadronic calorimeter muon identification system. able distinguish interactions...
Neutrinos in the cosmic ray flux with energies near 1 EeV and above are detectable Surface Detector array of Pierre Auger Observatory. We report here on searches through data from January 2004 until 20 June 2013. No neutrino candidates were found, yielding a limit to diffuse ultra-high energy neutrinos that challenges Waxman-Bahcall bound predictions. Neutrino identification is attempted using broad time-structure signals expected SD stations, efficiently done for all flavors interacting...
We present phase space distributions and multiplicities of K+, K−, ϕ mesons produced in Ar+KCl reactions at a kinetic beam energy 1.756 GeV/nucleon measured with the HADES spectrometer. The inverse slope parameters yields kaons supplement systematics previous measurements. percentage K− coming from decay is found to be 18±7%.6 MoreReceived 9 March 2009DOI:https://doi.org/10.1103/PhysRevC.80.025209©2009 American Physical Society
We present transverse momentum spectra, rapidity distribution and multiplicity of $ \Lambda$ -hyperons measured with the HADES spectrometer in reaction Ar(1.76AGeV) + KCl . The yield \Xi^{{-}}_{}$ is calculated from our previously reported /( \Sigma^{{0}}_{}$ ) ratio compared to other strange particle multiplicities. Employing a strangeness balance equation multiplicities yet unmeasured \Sigma^{{\pm}}_{}$ can be estimated. Finally statistical hadronization model used fit yields \pi^{-}_{}$ ,...
We report a measurement of the energy spectrum cosmic rays above 2.5×1018 eV based on 215 030 events. New results are presented: at about 1.3×1019 eV, spectral index changes from 2.51±0.03(stat)±0.05(syst) to 3.05±0.05(stat)±0.10(syst), evolving 5.1±0.3(stat)±0.1(syst) beyond 5×1019 while no significant dependence features declination is seen in accessible range. These can be reproduced models with energy-dependent mass composition. The density 5×1018 [5.66±0.03(stat)±1.40(syst)]×1053 erg...
We report first results on a deep subthreshold production of the doubly strange hyperon Xi;{-} in heavy-ion reaction. At beam energy 1.76A GeV reaction Ar + KCl was studied with High Acceptance Di-Electron Spectrometer at SIS18/GSI. A high-statistics and high-purity Lambda sample collected, allowing for investigation decay channel --> Lambdapi;{-}. The deduced Xi;{-}/(Lambda Sigma;{0}) ratio (5.6 +/- 1.2_{-1.7};{+1.8}) x 10;{-3} is significantly larger than available model predictions.
We present a search for the e+e− decay of hypothetical dark photon, also named U vector boson, in inclusive dielectron spectra measured by HADES p(3.5 GeV) + p, Nb reactions, as well Ar (1.756 GeV/u) KCl reaction. An upper limit on kinetic mixing parameter squared ϵ2 at 90% CL has been obtained mass range MU=0.02–0.55 GeV/c2 and is compared with world data set. For masses 0.03–0.1 GeV/c2, lowered respect to previous results, allowing now exclude large part region favored muon g−2 anomaly....
Neutrinos with energies above $10^{17}$ eV are detectable the Surface Detector Array of Pierre Auger Observatory. The identification is efficiently performed for neutrinos all flavors interacting in atmosphere at large zenith angles, as well Earth-skimming $\tau$ nearly tangential trajectories relative to earth. No neutrino candidates were found $\sim\,14.7$ years data taken up 31 August 2018. This leads restrictive upper bounds on their flux. $90\%$ C.L. single-flavor limit diffuse flux...
The Auger Engineering Radio Array (AERA) is part of the Pierre Observatory and used to detect radio emission cosmic-ray air showers. These observations are compared data surface detector stations Observatory, which provide well-calibrated information on energies arrival directions. response in 30--80 MHz regime has been thoroughly calibrated enable reconstruction incoming electric field. For latter, energy deposit per area determined from pulses at each observer position interpolated using a...
We present a new method for probing the hadronic interaction models at ultrahigh energy and extracting details about mass composition. This is done using time profiles of signals recorded with water-Cherenkov detectors Pierre Auger Observatory. The arise from mix muon electromagnetic components air showers. Using risetimes signals, we define parameter, which use to compare our observations predictions simulations. find, first, inconsistencies between data over greater range substantially...
A bstract Heavy Neutral Leptons (HNLs) are hypothetical particles predicted by many extensions of the Standard Model. These can, among other things, explain origin neutrino masses, generate observed matter-antimatter asymmetry in Universe and provide a dark matter candidate. The SHiP experiment will be able to search for HNLs produced decays heavy mesons travelling distances ranging between $$ \mathcal{O} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>O</mml:mi>...
We measure the energy emitted by extensive air showers in form of radio emission frequency range from 30 to 80 MHz. Exploiting accurate scale Pierre Auger Observatory, we obtain a radiation 15.8 \pm 0.7 (stat) 6.7 (sys) MeV for cosmic rays with an 1 EeV arriving perpendicularly geomagnetic field 0.24 G, scaling quadratically cosmic-ray energy. A comparison predictions state-of-the-art first-principle calculations shows agreement our measurement. The provides direct access calorimetric...
We report a first measurement for ultra-high energy cosmic rays of the correlation between depth shower maximum and signal in water Cherenkov stations air-showers registered simultaneously by fluorescence surface detectors Pierre Auger Observatory. Such is unique feature hybrid air-shower observatory with sensitivity to both electromagnetic muonic components. It allows an accurate determination spread primary masses cosmic-ray flux. Up till now, constraints on have been dominated systematic...
Employing the Bonn–Gatchina partial wave analysis framework (PWA), we have analyzed HADES data of reaction p(3.5GeV)+p→pK+Λ. This might contain information about kaonic cluster "ppK−" (with quantum numbers JP=0− and total isospin I=1/2) via its decay into pΛ. Due to interference effects in our coherent description data, a hypothetical K‾NN (or, specifically "ppK−") signal need not necessarily show up as pronounced feature (e.g. peak) an invariant mass spectrum like Our PWA includes variety...
A search for ultra-high energy photons with energies above 1 EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries achieved combining measurements longitudinal air-shower development particle content at ground measured fluorescence surface detectors, respectively. Only three candidates 1–2 are found, which compatible expected hadron-induced background. Upper limits on...
We present an analysis of proton number fluctuations in $\sqrt{s_{NN}}$ = 2.4 GeV Au+Au collisions measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI. With help extensive detector simulations done IQMD transport model events including nuclear clusters, various nuisance effects influencing observed cumulants have been investigated. Acceptance and efficiency corrections applied as a function fine grained rapidity transverse momentum bins, well considering local track...
We report the direct observation of muon neutrino interactions with SND@LHC detector at Large Hadron Collider. A dataset proton-proton collisions sqrt[s]=13.6 TeV collected by in 2022 is used, corresponding to an integrated luminosity 36.8 fb^{-1}. The search based on information from active electronic components detector, which covers pseudorapidity region 7.2<η<8.4, inaccessible other experiments collider. Muon candidates are identified through their charged-current interaction topology, a...
We present the transverse momentum spectra and rapidity distributions of ${\ensuremath{\pi}}^{\ensuremath{-}}$ ${\mathrm{K}}_{S}^{0}$ in Ar $+$ KCl reactions at a beam kinetic energy $1.756$ $A$ GeV measured with High Acceptance Di-Electron Spectrometer (HADES). The reconstructed sample is characterized by good event statistics for wide range rapidity. compare experimental to predictions Isospin Quantum Molecular Dynamics (IQMD) model. model calculations show that low momenta constitute...
We report measurements of electron pair production in elementary p+p and d+p reactions at 1.25 GeV/u with the HADES spectrometer. For first time, pairs were reconstructed for n+p by detecting proton spectator from deuteron breakup. find that yield invariant mass Me+e- > 0.15 GeV/c2 is about an order magnitude larger as compared to p+p. A comparison model calculations demonstrates mechanism not sufficiently described yet. The spectra measured C+C are compatible a superposition collisions,...
We present results on dielectron production in ${}^{40}\mathrm{Ar}+\mathrm{KCl}$ collisions at 1.76$A$ GeV. For the first time $\ensuremath{\omega}$ mesons could be reconstructed a heavy-ion reaction bombarding energy which is well below threshold free nucleon-nucleon collisions. The multiplicity has been extracted and compared to yields of other particles, particular $\ensuremath{\varphi}$ meson. At intermediate ${e}^{+}{e}^{\ensuremath{-}}$ invariant masses, we find strong enhancement pair...