muEDM Collaboration Meeting October 2021


Principle goal for the meeting:  Decision on proposal submission

Start of meeting: October 7, 9h30
End of meeting:  October 8, 12h00
Zoom: Online Meeting

The Next PSI Users' Meeting Ring is on January 24 - 27, 2022. This is the meeting where the Research Committee for Particle Physics at the Ring Cyclotron decides on experiments' proposals.

If we decide to submit a full proposal to the research committee for the 2022 call, we need to submit it by January 10, 2022.

In the last months, we have started to work in task groups on the main questions of the muEDM experiment.

  • Theory and motivation
  • Muon beamline and injection
  • Systematic effects and magnetic/electric field configuration
  • Muon identification and trigger
  • Positron tracker

In this meeting we will have three session:

Oct 7, 9:30  - 11:00  Overview / beamline and injection
Oct 7, 14:00 -15:30  Magnetic simulations and systematic effects
Oct 8, 10:30 -12:00 Muon and positron detection / Organization

Please contact me, Philipp Schmidt-Wellenburg, if you have contributions.

  • Thursday, October 7
    • 9:30 AM 11:00 AM
      Welcome / Overview / Beamline and Injection 1h 30m
      • muon EDM - next steps? 30m

        Status of the current concept.
        How do we want to carry on?

        Speaker: Philipp Schmidt-Wellenburg (PSI - Paul Scherrer Institut)
      • Discussion muEDM task organization 30m
        Speaker: Philipp Schmidt-Wellenburg (PSI - Paul Scherrer Institut)
    • 2:00 PM 3:30 PM
      Systematic effect and magnet design 1h 30m
      • MuEDM magnet design - development of an open source optimization tool 30m

        An ongoing effort is conducted to find the optimal design of the MuEDM magnet to fuflill the magnetic specifications to trap muons. The design should be as simple as possible limiting in particular the segmentation of the magnet to ease the fabrication. An optimization tool is being developed to reach that goal while providing a generic tool for further use. This tool implements a genetic algorithm (GA) using python and the FEM open source cross platform software Onelab (mesh generator Gmsh and solver GetDP) to estimate the magnetic field. This magnetic field is computed off axis and compared to a target distribution which bundles the magnetic specifications. The dimensions of the coils making the magnet and the current densities associated with the coils are optimized.
        The code has been implemented. First tries have been carried out on a set of coils to test the code. The debugging phase is nearly completed and a benchmark is considered to guaranty the correct response of the algorithm.

        Speaker: Dr Frederic Trillaud Pighi (Universidad Nacional Autonoma Mexico)
      • Discussion - next steps magnet design 20m
        Speaker: Philipp Schmidt-Wellenburg (PSI - Paul Scherrer Institut)
      • Measurement of multiple Coulomb scattering in thin foils with pixel telescopes 20m

        We plan to measure multiple Coulomb scattering in thin foils of several materials in a PSI beam time in December. For this we will use a HV-MAPS (MuPix) telescope. The talk will present the plans as well as an earlier measurement performed with the EUDET telescope at DESY with electrons of a few GeV"

        Speaker: Niklaus Berger (Mainz University, Insititute for Nuclear Physics)
      • Discussion - muon beam time 2021 20m
        Speaker: Philipp Schmidt-Wellenburg (PSI - Paul Scherrer Institut)
  • Friday, October 8
    • 10:30 AM 12:00 PM
      Muon and Positron detection / Organization 1h 30m
      • Simulation-based pixel and time resolution analysis for positron tracking using muSRSim 25m

        The aim of this investigation is to optimize the configuration of a detector used to measure the Electric Dipole Moment (EDM) of the muon through the frozen spin technique. We investigate the required pixel resolution to accurately reconstruct the trajectory of positrons in a magnetic field, which are emitted from a muon storage ring. A simple helix fitting algorithm is proposed which reconstructs the trajectories of positrons in a Geant4 simulation, specifically musrSim. This algorithm allows to determine the decay vertex. The muon EDM is determined through measuring the up-down asymmetry as a function of time, and the influence of the time quantisation precision on the accuracy of the measured muon EDM is subsequently investigated. Some inconsistencies in the maximal observed decay asymmetry reveal potential sources of systematic errors in the momentum spectrum measured by the detection mechanism, which could be corrected by measuring the asymmetry through g-2 precession.

        Speaker: Alexander Jaeger (ETHZ)
      • General status - Muon detection 15m
        Speaker: Angela Papa (PSI - Paul Scherrer Institut)
      • Standalone MC simulation for the plastics scintillator based detectors - Status 15m
        Speaker: Bastiano Vitaly
      • R&D activities in Roma 15m
        Speaker: Francesco Renga (INFN Roma)
      • Discussion 15m