R. Lollini
A5022797814- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Dark Matter and Cosmic Phenomena
- Neutrino Physics Research
- Computational Physics and Python Applications
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Stochastic processes and statistical mechanics
- Atomic and Subatomic Physics Research
- Black Holes and Theoretical Physics
- Astrophysics and Cosmic Phenomena
- Cosmology and Gravitation Theories
- Wireless Body Area Networks
- Markov Chains and Monte Carlo Methods
- Algorithms and Data Compression
- International Science and Diplomacy
- Nuclear physics research studies
- Advanced NMR Techniques and Applications
- Pulsars and Gravitational Waves Research
- Methane Hydrates and Related Phenomena
- Superconducting Materials and Applications
- Antenna Design and Analysis
Istituto Nazionale di Fisica Nucleare, Sezione di Perugia
2017-2024
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2017-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Napoli
2024
Scuola Superiore Meridionale
2024
Centre National de la Recherche Scientifique
2023-2024
Roma Tre University
2024
Aix-Marseille Université
2023-2024
Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara
2022-2023
Universitat de Barcelona
2023
University of Groningen
2023
A bstract The NA62 experiment reports the branching ratio measurement $$ \mathrm{BR}\left({K}^{+}\to {\pi}^{+}\nu \overline{\nu}\right)=\left({10.6}_{-3.4}^{+4.0}\left|{}_{\mathrm{stat}}\right.\pm {0.9}_{\mathrm{syst}}\right)\times {10}^{-11} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>BR</mml:mi> <mml:mfenced> <mml:mrow> <mml:msup> <mml:mi>K</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:mo>→</mml:mo> <mml:mi>π</mml:mi> <mml:mi>ν</mml:mi> <mml:mover> <mml:mo>¯</mml:mo>...
A search for heavy neutral lepton production in $K^+$ decays using a data sample collected with minimum bias trigger by the NA62 experiment at CERN 2015 is reported. Upper limits $10^{-7}$ to $10^{-6}$ level are established on elements of extended neutrino mixing matrix $|U_{\ell 4}|^2$ ($\ell=e,\mu$) mass range $170-448~{\rm MeV}/c^2$. This improves results from previous searches decays, setting more stringent and extending range.
A search for heavy neutral lepton (N) production in K+→e+N decays using the data sample collected by NA62 experiment at CERN 2017–2018 is reported. Upper limits of extended neutrino mixing matrix element |Ue4|2 are established level 10−9 over most accessible mass range 144–462 MeV/c2, with assumption that lifetime exceeds 50 ns. These improve significantly upon those previous and decay searches. The favoured Big Bang Nucleosynthesis excluded up to a about 340 MeV/c2.
The NA62 experiment at CERN reports searches for $K^+\to\mu^+N$ and $K^+\to\mu^+\nu X$ decays, where $N$ $X$ are massive invisible particles, using the 2016-2018 data set. particle is assumed to be a heavy neutral lepton, results expressed as upper limits of ${\cal O}(10^{-8})$ neutrino mixing parameter $|U_{\mu4}|^2$ masses in range 200-384 MeV/$c^2$ lifetime exceeding 50 ns. considered scalar or vector hidden sector mediator decaying an final state, decay branching fraction 10-370 reported...
A bstract The NA62 experiment at the CERN SPS reports a study of sample 4 × 10 9 tagged π 0 mesons from K + → ( γ ), searching for decay to invisible particles. No signal is observed in excess expected background fluctuations. An upper limit . − set on branching ratio 90% confidence level, improving previous results by factor 60. This result can also be interpreted as model- independent X , where particle escaping detection with mass range 0.110–0.155 GeV /c 2 and rest lifetime greater than...
A sample of 3984 candidates the K+→π+γγ decay, with an estimated background 291±14 events, was collected by NA62 experiment at CERN during 2017–2018. In order to describe observed di-photon mass spectrum, next-to-leading contribution in chiral perturbation theory found be necessary. The decay branching ratio full kinematic range is measured (9.61±0.17)×10−7. first search for production and prompt axion-like particle gluon coupling process K+→π+a, a→γγ also reported.
A bstract search for the K + → π X decay, where is a long-lived feebly interacting particle, performed through an interpretation of $$ {\pi}^{+}\nu \overline{\nu} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>π</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:mi>ν</mml:mi> <mml:mover> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> analysis data collected in 2017 by NA62 experiment at CERN. Two ranges masses, 0–110 MeV /c 2 and 154–260 , lifetimes above 100 ps are...
Searches for lepton number violating K+→π−e+e+ and K+→π−π0e+e+ decays have been performed using the complete dataset collected by NA62 experiment at CERN in 2016–2018. Upper limits of 5.3×10−11 8.5×10−10 are obtained on decay branching fractions 90% confidence level. The former result improves a factor four over previous best limit, while latter represents first limit rate.
A bstract The NA62 experiment at CERN, designed to study the ultra-rare decay K + → π $$ \nu \overline{\nu} <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>ν</mml:mi> <mml:mover> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> , has also collected data in beam-dump mode. In this configuration, dark photons may be produced by protons dumped on an absorber and reach a volume beginning 80 m downstream. search for decaying flight μ − pairs is reported, based sample of 1 . 4 × 10 17...
The first search for ultra-rare K+ decays into the π+e+e−e+e− final state is reported, using a dataset collected by NA62 experiment at CERN in 2017–2018. An upper limit of 1.4×10−8 90% CL obtained branching ratio K+→π+e+e−e+e− decay, predicted Standard Model to be (7.2±0.7)×10−11. Upper limits are level 10−9 ratios two prompt decay chains involving pair-production hidden-sector mediators: K+→π+aa, a→e+e− and K+→π+S, S→A′A′, A′→e+e−.
The NA62 experiment at CERN, designed to study the ultra-rare decay $K^+ \to \pi^+\nu\overline{\nu}$, has also collected data in beam-dump mode. In this configuration, dark photons may be produced by protons dumped on an absorber and reach a volume beginning 80 m downstream. A search for decaying flight $\mu^+\mu^-$ pairs is reported, based sample of $1.4 \times 10^{17}$ dump 2021. No evidence photon signal observed. region parameter space excluded 90% CL, improving previous experimental...
Abstract The NA62 experiment at CERN utilises a differential Cherenkov counter with achromatic ring focus (CEDAR) for tagging kaons within an unseparated monochromatic beam of charged hadrons. CEDAR-H detector was developed to minimise the amount material in path by using hydrogen gas as radiator medium. shown satisfy kaon requirements test-beam before installation and commissioning experiment. performance measured data collected 2023.
The NA62 experiment at CERN, configured in beam-dump mode, has searched for dark photon decays flight to electron-positron pairs using a sample of 1.4×10^{17} protons on dump collected 2021. No evidence signal is observed. combined result searches lepton-antilepton final states presented and region the parameter space excluded 90% confidence level, improving previous experimental limits mass values between 50 600 MeV/c^{2} coupling range 10^{-6} 4×10^{-5}. An interpretation e^{+}e^{-} search...
A large RICH detector is used in NA62 to suppress the muon contamination charged pion selection by a factor 100 momentum range between 15 and 35 GeV/c. The consists of 17 m long tank (vessel), filled with neon gas at atmospheric pressure. Cherenkov light reflected mosaic 20 spherical mirrors focal length, placed downstream end, collected 1952 photomultipliers (PMTs) upstream end. In this paper characterization before installation mirror support system are described. procedure laser alignment...
The first search for ultra-rare $K^+$ decays into the $\pi^+e^+e^-e^+e^-$ final state is reported, using a dataset collected by NA62 experiment at CERN in 2017-2018. An upper limit of $1.4\times 10^{-8}$ 90% CL obtained branching ratio $K^+\to\pi^+e^+e^-e^+e^-$ decay, predicted Standard Model to be $(7.2\pm0.7)\times 10^{-11}$. Upper limits are level $10^{-9}$ ratios two prompt decay chains involving pair-production hidden-sector mediators: $K^+\to\pi^+aa$, $a\to e^+e^-$ and $K^+\to\pi^+S$,...
A large RICH detector is used in NA62 to suppress the muon contamination charged pion sample by a factor of 100 momentum range between 15 and 35 GeV/c. Cherenkov light collected 1952 photomultipliers placed at upstream end. In this paper characterization dedicated Frontend Data Acquisition electronics are described, time resolution detection efficiency measurement presented.
A sample of $1.3 \times 10^5$ $K^+ \to π^0 e^+ νγ$ candidates with less than 1% background was collected by the NA62 experiment at CERN SPS in 2017-2018. Branching fraction measurements are obtained percent relative precision three restricted kinematic regions, improving on existing results a factor larger two. An asymmetry, possibly related to T-violation, is investigated no evidence observed within achieved precision.
The NA62 experiment at CERN was designed to measure the branching ratio of ultra-rare K + → π ν decay with a decay-in-flight technique.The Standard Model prediction for this is very precise and process an ideal candidate indirect search New Physics high-mass scale.NA62 took physics data from 2016 2018: results analysis in 2016+2017 sets are presented.Moreover, high-intensity setup, flexibility its trigger system, hermetic coverage make useful tool exotic particles MeV-GeV range weakly...