A5025021429- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Muon and positron interactions and applications
- Particle accelerators and beam dynamics
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Radiation Detection and Scintillator Technologies
- Quantum, superfluid, helium dynamics
- Astrophysics and Cosmic Phenomena
- Scientific Research and Discoveries
- Cosmology and Gravitation Theories
- Nuclear Physics and Applications
California University of Pennsylvania
2024
University of Washington
2021-2023
University of Bern
2019-2022
University of Liverpool
2021
Paul Scherrer Institute
2016-2019
ETH Zurich
2016
École Polytechnique Fédérale de Lausanne
2016
Fermi National Accelerator Laboratory
2013
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...
We present the result of an experiment to measure electric dipole moment (EDM) neutron at Paul Scherrer Institute using Ramsey's method separated oscillating magnetic fields with ultracold neutrons (UCN). Our measurement stands in long history EDM experiments probing physics violating time reversal invariance. The salient features this were use a Hg-199 co-magnetometer and array optically pumped cesium vapor magnetometers cancel correct for field changes. statistical analysis was performed...
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.
We present a new measurement of the positive muon magnetic anomaly, a_{μ}≡(g_{μ}-2)/2, from Fermilab Muon g-2 Experiment using data collected in 2019 and 2020. have analyzed more than 4 times number positrons decay our previous result 2018 data. The systematic error is reduced by factor 2 due to better running conditions, stable beam, improved knowledge field weighted distribution, ω[over ˜]_{p}^{'}, anomalous precession frequency corrected for beam dynamics effects, ω_{a}. From ratio...
The Muon g-2 Experiment at Fermi National Accelerator Laboratory (FNAL) has measured the muon anomalous precession frequency $ω_a$ to an uncertainty of 434 parts per billion (ppb), statistical, and 56 ppb, systematic, with data collected in four storage ring configurations during its first physics run 2018. When combined a precision measurement magnetic field experiment's ring, determines anomaly $a_μ({\rm FNAL}) = 116\,592\,040(54) \times 10^{-11}$ (0.46 ppm). This article describes...
The Fermi National Accelerator Laboratory has measured the anomalous precession frequency $a^{}_\mu = (g^{}_\mu-2)/2$ of muon to a combined precision 0.46 parts per million with data collected during its first physics run in 2018. This paper documents measurement magnetic field storage ring. is monitored by nuclear resonance systems and calibrated terms equivalent proton spin spherical water sample at 34.7$^\circ$C. weighted distribution resulting $\tilde{\omega}'^{}_p$, denominator ratio...
The Mu3e experiment aims to find or exclude the lepton flavour violating decay $\mu \rightarrow eee$ at branching fractions above $10^{-16}$. A first phase of using an existing beamline Paul Scherrer Institute (PSI) is designed reach a single event sensitivity $2\cdot 10^{-15}$. We present overview all aspects technical design and expected performance phase~I detector. high rate up $10^{8}$ muon decays per second low momenta electrons positrons pose unique set challenges, which we tackle...
We present details on a new measurement of the muon magnetic anomaly, $a_\mu = (g_\mu -2)/2$. The result is based positive data taken at Fermilab's Muon Campus during 2019 and 2020 accelerator runs. uses $3.1$ GeV$/c$ polarized muons stored in $7.1$-m-radius storage ring with $1.45$ T uniform field. value $ a_{\mu}$ determined from measured difference between spin precession frequency its cyclotron frequency. This normalized to strength field, using Nuclear Magnetic Resonance (NMR). ratio...
We present a new measurement of the positive muon magnetic anomaly, $a_\mu \equiv (g_\mu - 2)/2$, from Fermilab Muon $g\!-\!2$ Experiment using data collected in 2019 and 2020. have analyzed more than 4 times number positrons decay our previous result 2018 data. The systematic error is reduced by factor 2 due to better running conditions, stable beam, improved knowledge field weighted distribution, $\tilde{\omega}'^{}_p$, anomalous precession frequency corrected for beam dynamics effects,...
We report on a search for dark matter axionlike particles (ALPs) using Ramsey-type apparatus cold neutrons. A hypothetical ALP-gluon coupling would manifest in neutron electric dipole moment signal oscillating time. Twenty-four hours of data have been analyzed frequency range from 23 μHz to 1 kHz, and no significant has found. The usage present dark-matter models allows one constrain the ALPs gluons mass 10^{-19} 4×10^{-12} eV. best limit C_{G}/f_{a}m_{a}=2.7×10^{13} GeV^{-2} (95% C.L.) is...
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...
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,...
Meson factories are powerful drivers of diverse physics programs. With beam powers already in the MW-regime attention has to be turned target and line design further significantly increase surface muon rates available for experiments. For this reason we have explored possibility using a neutron spallation as source muons by performing detailed Geant4 simulations with pion production cross sections based on parametrization existing data. While outperforms standard targets backward direction...
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}...
This paper presents the beam dynamics systematic corrections and their uncertainties for Run-1 data set of Fermilab Muon g-2 Experiment. Two to measured muon precession frequency $\omega_a^m$ are associated with well-known effects owing use electrostatic quadrupole (ESQ) vertical focusing in storage ring. An average vertically oriented motional magnetic field is felt by relativistic muons passing transversely through radial electric components created ESQ system. The correction depends on...
We report on the Beam EDM experiment, which aims to employ a pulsed cold neutron beam search for an electric dipole moment instead of established use storable ultracold neutrons. present brief overview basic measurement concept and current status our proof-of-principle Ramsey apparatus.
We report on a search for dark matter axion-like particles (ALPs) using Ramsey-type apparatus cold neutrons. A hypothetical ALP-gluon-coupling would manifest in neutron electric dipole moment signal oscillating time. Twenty-four hours of data have been analyzed frequency range from 23 $μ$Hz to 1 kHz, and no significant has found. The usage present dark-matter models allows constrain the coupling ALPs gluons mass $10^{-19}$ $4 \times 10^{-12}$ eV. best limit $C_G$/$f_a m_a = 2.7 10^{13}$...