M. Hildebrandt
A5050682096- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Neutrino Physics Research
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Muon and positron interactions and applications
- Atomic and Molecular Physics
- Atomic and Subatomic Physics Research
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Plasma Diagnostics and Applications
- Nuclear physics research studies
- Medical Imaging Techniques and Applications
- Advanced Chemical Physics Studies
- Cosmology and Gravitation Theories
- Astrophysics and Cosmic Phenomena
- Advanced Semiconductor Detectors and Materials
- Black Holes and Theoretical Physics
- Gas Dynamics and Kinetic Theory
- Enhanced Oil Recovery Techniques
- Computational Physics and Python Applications
- History and advancements in chemistry
Paul Scherrer Institute
2015-2024
ETH Zurich
2011-2023
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
2023
Istituto Nazionale di Fisica Nucleare, Sezione di Roma I
2014-2021
Heidelberg University
1997-2021
The University of Tokyo
2011-2021
Illinois Institute of Technology
2020
Istituto Nazionale di Fisica Nucleare, Sezione di Genova
2010-2014
Laboratoire Kastler Brossel
2011
Centre National de la Recherche Scientifique
2011
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 analysis of a combined data set, totaling 3.6 × 10(14) stopped muons on target, in the search for lepton flavor violating decay μ(+) → e(+)γ is presented. collected by MEG experiment at Paul Scherrer Institut show no excess events compared to background expectations and yield new upper limit branching ratio this 5.7 10(-13) (90% confidence level). This represents four times more stringent than previous world best set MEG.
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 result based on an analysis of the data collected by MEG detector at Paul Scherrer Institut in 2009 and 2010, search lepton-flavor-violating decay μ+→e+γ. The likelihood combined sample, which corresponds to total 1.8×1014 muon decays, gives 90% C.L. upper limit 2.4×10−12 branching ratio μ+→e+γ decay, constituting most stringent existence this date.Received 31 July 2011DOI:https://doi.org/10.1103/PhysRevLett.107.171801© 2011 American Physical Society
Cross sections for elastic and proton-dissociative photoproduction of J/ψ mesons are measured with the H1 detector in positron-proton collisions at HERA. The data were collected ep centre-of-mass energies $\sqrt{s}\approx318~\mathrm{GeV}$ $\sqrt {s}\approx225 \ \mbox{GeV}$ , corresponding to integrated luminosities $\mathcal{L} = 130~\mbox{pb}^{-1}$ 10.8~\mbox{pb}^{-1}$ respectively. cross as a function photon-proton energy range 25<W γp <110 GeV. Differential dσ/dt, where t is squared...
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...
We propose an experiment (Mu3e) to search for the lepton flavour violating decay mu+ -> e+e-e+. aim ultimate sensitivity of one in 10^16 mu-decays, four orders magnitude better than previous searches. This is made possible by exploiting modern silicon pixel detectors providing high spatial resolution and hodoscopes using scintillating fibres tiles precise timing information at particle rates.
A measurement is presented of the inclusive neutral current e\pm p scattering cross section using data collected by H1 experiment at HERA during years 2003 to 2007 with proton beam energies Ep 920, 575, and 460 GeV. The kinematic range covers low absolute four-momentum transfers squared, 1.5 GeV2 < Q2 120 GeV2, small values Bjorken x, 2.9 \cdot 10-5 x 0.01, extends high inelasticity up y = 0.85. structure function FL measured combining new results previously published 920 GeV 820...
The MEG (Mu to Electron Gamma) experiment has been running at the Paul Scherrer Institut (PSI), Switzerland since 2008 search for decay μ +→e+ γ by using one of most intense continuous + beams in world. This paper presents components: positron spectrometer, including a thin target, superconducting magnet, set drift chambers measuring muon vertex and momentum, timing counter time, liquid xenon detector photon energy, position time. trigger system, read-out electronics data acquisition system...
A BSTRACT Inclusive e ± p single and double differential cross sections for neutral charged current deep inelastic scattering processes are measured with the H1 detector at HERA. The data were taken a centre-of-mass energy of $ \sqrt {s} = {319} GeV total integrated luminosity 333.7 pb −1 shared between two lepton beam charges longitudinal polarisation modes. in range negative four-momentum transfer squared, Q 2 , 60 50 000 Bjorken x 0 . 0008 65. measurements combined earlier published...
Abstract The energy levels of hydrogen-like atomic systems can be calculated with great precision. Starting from their quantum mechanical solution, they have been refined over the years to include electron spin, relativistic and field effects, tiny shifts related complex structure nucleus. These caused by nuclear are vastly magnified in formed a negative muon nucleus, so spectroscopy these muonic ions used investigate high Here we present measurement two 2S–2P transitions helium-4 ion that...
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...
A measurement of elastic deeply virtual Compton scattering γ∗p→γp using e−p collision data recorded with the H1 detector at HERA is presented. The analysed sample corresponds to an integrated luminosity 145 pb−1. cross section measured as a function virtuality Q2 exchanged photon and centre-of-mass energy W γ∗p system in kinematic domain 6.5<Q2<80 GeV2, 30<W<140 GeV |t|<1 where t denotes squared momentum transfer proton vertex. determined differentially for different values exponential...
Diffractive electroproduction of ρ and ϕ mesons is measured at HERA with the H1 detector in elastic proton dissociative channels. The data correspond to an integrated luminosity 51 pb−1. About 10500 2000 φ events are analysed kinematic range squared photon virtuality 2.5 ≤ Q 2 60 GeV2, photon-proton centre mass energy 35 W 180 GeV four-momentum transfer |t| 3 GeV2. total, longitudinal transverse cross sections as a function 2, |t|. measurements show transition dominantly "hard" behaviour,...
Inclusive charm and beauty cross sections are measured in e-p e+p neutral current collisions at HERA the kinematic region of photon virtuality 5<Q^2<2000 GeV^2 Bjorken scaling variable 0.0002<x<0.05. The data were collected with H1 detector years 2006 2007 corresponding to an integrated luminosity 189 pb^-1. numbers events determined using variables reconstructed by vertex including impact parameter tracks primary position secondary vertex. measurements combined previous compared QCD predictions.
A first measurement is reported of the longitudinal proton structure function F_L(x,Q^2) at ep collider HERA. It based on inclusive deep inelastic e^+p scattering cross section measurements with a positron beam energy 27.5 GeV and energies 920, 575 460 GeV. Employing dependence section, F_L measured in range squared four-momentum transfers 12 < Q^2 90 GeV^2 low Bjorken x 0.00024 0.0036. The values agree higher order QCD calculations parton densities obtained using data previously
Inclusive $$ep$$ double differential cross sections for neutral current deep inelastic scattering are measured with the H1 detector at HERA. The data were taken a lepton beam energy of $$27.6$$ GeV and two proton energies $$E_p=460$$ 575 corresponding to centre-of-mass 225 252 GeV, respectively. measurements cover region $$6.5\times 10^{-4} \le x 0.65$$ $$35\le Q^2 800$$ $$^2$$ up $$y=0.85$$ . used together previously published $$E_p=920$$ lower $$Q^2$$ , $$575$$ $$920$$ extract longitudinal...
The production of jets is studied in deep-inelastic ep scattering at large negative four momentum transfer squared 150<Q^2<15000 GeV^2 using HERA data taken 1999-2007, corresponding to an integrated luminosity 395 pb^-1. Inclusive jet, 2-jet and 3-jet cross sections, normalised the neutral current are measured as functions Q^2, jet transverse proton fraction. measurements well described by perturbative QCD calculations next-to-leading order corrected for hadronisation effects. strong...