G. F. Tassielli
A5085274386- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Radiation Detection and Scintillator Technologies
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Muon and positron interactions and applications
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Atomic and Subatomic Physics Research
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Radiation Therapy and Dosimetry
- Particle accelerators and beam dynamics
- Nuclear physics research studies
- Power Line Communications and Noise
- Distributed and Parallel Computing Systems
- International Science and Diplomacy
- Laser-Plasma Interactions and Diagnostics
- Medical Imaging Techniques and Applications
- Air Quality Monitoring and Forecasting
- Laser-induced spectroscopy and plasma
- CCD and CMOS Imaging Sensors
- Radioactive Decay and Measurement Techniques
Istituto Nazionale di Fisica Nucleare, Sezione di Bari
2022-2025
Istituto Nazionale di Fisica Nucleare, Sezione di Lecce
2015-2024
University of Bari Aldo Moro
2022-2024
A. Alikhanyan National Laboratory
2022-2024
University of Salento
2006-2023
California Institute of Technology
2018-2022
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
2015-2022
Istituto Nazionale di Fisica Nucleare
2012-2022
Joint Institute for Nuclear Research
2021-2022
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati
2021-2022
The final results of the search for lepton flavour violating decay $$\mathrm {\mu }^+ \rightarrow \mathrm {e}^+ {\gamma }$$ based on full dataset collected by MEG experiment at Paul Scherrer Institut in period 2009–2013 and totalling $$7.5\times 10^{14}$$ stopped muons target are presented. No significant excess events is observed with respect to expected background a new upper limit branching ratio this $$ \mathcal{B} (\mu ^+ \mathrm{e}^+ \gamma ) < 4.2 \times 10^{-13}$$ (90 % confidence...
The MEG experiment, designed to search for the mu+->e+ gamma decay at a 10^-13 sensitivity level, completed data taking in 2013. In order increase reach of experiment by an magnitude level 6 x 10-14 branching ratio, total upgrade, involving substantial changes has been undertaken, known as II. We present both motivation upgrade and detailed overview design expected detector performance.
Abstract The MEG II experiment, based at the Paul Scherrer Institut in Switzerland, reports result of a search for decay $$\upmu ^+ \rightarrow {\textrm{e}}^+ \upgamma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:mo>→</mml:mo> <mml:mtext>e</mml:mtext> </mml:mrow> <mml:mi>γ</mml:mi> </mml:math> from data taken first physics run 2021. No excess events over expected background is observed, yielding an...
Abstract The MEG II experiment, located at the Paul Scherrer Institut (PSI) in Switzerland, is successor to which completed data taking 2013. started fully operational 2021, with goal of improving sensitivity $$\upmu ^+ \rightarrow {\textrm{e}}^+ \upgamma $$ <mml:math...
The MEG experiment took data at the Paul Scherrer Institute in years 2009–2013 to test violation of lepton flavor conservation law, which originates from an accidental symmetry that Standard Model elementary particle physics has, and published most stringent limit on charged violating decay μ+→e+γ: BR(μ+→e+γ) <4.2×10−13 90% confidence level. detector has been upgraded order reach a sensitivity 6×10−14. basic principle II is achieve highest possible using full muon beam intensity (7×107...
Abstract The cylindrical drift chamber is the most innovative part of MEG II detector, upgraded version experiment. differs from one because it a single volume structure, instead segmented one, chosen to improve its resolutions and efficiency in detecting low energy positrons muon decays at rest. In this paper, we show characteristics performances fundamental apparatus discuss impact higher resolution on sensitivity Because structure high quality will be cornerstone development an ideal...
Abstract We present the first direct search for lepton flavour violating muon decay mediated by a new light particle X, $$\upmu ^+ \rightarrow \mathrm {e}^+\mathrm {X}, {X} \upgamma \ $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>μ</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:mo>→</mml:mo> <mml:mi>e</mml:mi> </mml:mrow> <mml:mi>X</mml:mi> <mml:mo>,</mml:mo> <mml:mi>γ</mml:mi> <mml:mspace /> </mml:math> . This uses dataset resulting from...
Drift chambers operated with helium-based gas mixtures represent a common solution for tracking charged particles keeping the material budget in sensitive volume to minimum. The drawback of this is worsening spatial resolution due primary ionisation fluctuations, which limiting factor high granularity drift like MEG II tracker. We report on measurements performed three different prototypes chamber aimed at determining achievable single-hit resolution. were helium/isobutane and exposed cosmic...
We studied the radiative muon decay $μ^+ \to e^+ν\barνγ$ by using for first time an almost fully polarized source. identified a large sample (~13000) of these decays in total 1.8x10^14 positive collected MEG experiment years 2009--2010 and measured branching ratio B($μ^+ e^+ν\barνγ$) = (6.03+-0.14(stat.)+-0.53(sys.))x10^-8 E_e > 45 MeV E_γ 40 MeV, consistent with Standard Model prediction. The precise measurement this mode provides basic tool timing calibration, normalization channel,...
The Mu2e experiment at Fermilab searches the neutrino-less conversion of muon into electron in field an Aluminum nucleus. If such a process will be observed, it proof charged-lepton-flavor-violation (cLFV), otherwise set upper limit Rμe < 6 × 10−17 @ 90% C.L. (which represents improvement by 3–4 order magnitude over existing limit). detector apparatus consists magnetic spectrometer, devoted to measurement electrons momentum, and electromagnetic calorimeter (EMC) which provides independent...
The MEG II experiment, based at the Paul Scherrer Institut in Switzerland, reports result of a search for decay $\mu^+\to e^+\gamma$ from data taken first physics run 2021. No excess events over expected background is observed, yielding an upper limit on branching ratio B($\mu^+\to e^+\gamma$) < $7.5 \times 10^{-13}$ (90% C.L.). combination this and obtained by gives $3.1 C.L.), which most stringent to date. A ten-fold larger sample being collected during years 2022-2023, data-taking will...
The MEG experiment makes use of one the world's most intense low energy muon beams, in order to search for lepton flavour violating process $\mu^{+} \rightarrow {\rm e}^{+} \gamma$. We determined residual beam polarization at thin stopping target, by measuring asymmetry angular distribution Michel decay positrons as a function energy. initial production is predicted be $P_{\mu} = -1$ Standard Model (SM) with massless neutrinos. estimated our -0.85 \pm 0.03 ~ (stat)} { }^{+ 0.04}_{-0.05}...
The Mu2e experiment at Fermilab searches for the charged-lepton flavour violating (CLFV) conversion of a negative muon into an electron in field aluminum nucleus, with distinctive signature mono-energetic energy slightly below rest mass (104.967 MeV). goal is to improve by four orders magnitude search sensitivity respect previous experiments. Any observation CLFV signal will be clear indication new physics. detector composed tracker, electro- magnetic calorimeter and external veto cosmic...
The Mu2e experiment is constructing a calorimeter consisting of 1,348 undoped CsI crystals in two disks. Each crystal has dimension 34 x 200 mm, and readout by large area silicon PMT array. A series technical specifications was defined according to physics requirements. Preproduction were procured from three firms: Amcrys, Saint-Gobain Shanghai Institute Ceramics. We report the quality assurance on crystal's scintillation properties their radiation hardness against ionization dose neutrons....
The reconstruction of the positron trajectory in MEG-II experiment searching for $\mu^+ \to e^+ \gamma$ decay uses a cylindrical drift chamber operated with helium-isobutane gas mixture. A stable performance detector terms its electron properties, avalanche multiplication, and mixture controlled composition purity has to be provided continuously monitored. In this paper we describe strategies adopted meet requirements imposed by target sensitivity MEG-II, including construction commissioning...
An ultra-low mass Tracking Chamber with Particle Identification capabilities is proposed for a future $e^{+}e^{-}$ collider. Details about the construction parameters of drift chamber including both inspection new material wires , techniques soldiering wires, development an improved schema cell and choice gas mixture are described. The performance tracking studied together Improved particle identification obtained by using cluster counting technique.
An observation of Charged Lepton Flavor Violation (CLFV) would be unambiguous evidence for physics beyond the Standard Model. The Mu2e and COMET experiments, under construction, are designed to push sensitivity CLFV in mu e conversion process unprecedented levels. Whether is observed or not, there a strong case made further improving sensitivity, examining on additional target materials. Mu2e-II proposed upgrade Mu2e, with at least an order magnitude rate over Mu2e. approach challenges this...
The MEG II experiment, located at the Paul Scherrer Institut (PSI) in Switzerland, is successor to which completed data taking 2013. started fully operational 2021, with goal of improving sensitivity mu+ -> e+ gamma decay down 6e-14 almost an order magnitude better than current limit. In this paper, we describe operation and performance experiment give a new estimate its versus acquisition time.