Conveners
Parallel: WG4: Magnetic Moments
- Samuel Grant ()
Parallel: WG4: LFV at colliders and muon EDM
- Gavin Hesketh (UCL)
Parallel: WG4: BSM and Muons
- Kim Siang Khaw (University of Washington)
Parallel: WG4: Muon Conversion
- Simon Corrodi ()
The Muon $g-2$ experiment at Fermilab is progressing towards its physics goal of measuring the muon anomalous magnetic moment with the unprecedented precision of 140 parts per billion. The experiment collected proposed statistics (number of detected decay positrons) and completed the scientific operation in June 2023. Two previous publications in 2021 and 2023 were based on the data taken in...
In the Muon g-2 Experiment at Fermilab, the muon magnetic moment anomaly is measured by observing muon decays inside a magnetic storage ring, in order to test a potential discrepancy between past experiments and the Standard Model prediction. Precise knowledge of the magnetic field experienced by muons in the ring is necessary in order to reach the experiment’s unprecedented uncertainty goal...
The Muon g-2 experiment at Fermilab is analyzing the final data set collected from 2021 to 2023. Our most recent measurement of the positive muon magnetic anomaly, published in 2023, reached a precision of 200 parts per billion (ppb) with a total systematic uncertainty of 70 ppb. To calculate the uncertainty of our final experimental value, we need to assess the systematic effects that arise...
The J-PARC muon g-2/EDM experiment aims to measure the muon magnetic moment anomaly ($a_μ$ = (g-2)/2) and to search for the muon electric dipole moment, with sensitivity comparable to the highest in the world. This will be achieved using a small-emittance muon beam, created by cooling muons to thermal energy at room temperature and accelerating them with a multi-stage linac. The small...
Lepton flavour violation (LFV), and lepton flavour university violation (LFUV), are a striking signature of potential beyond the Standard Model physics. This talk presents recent searches and tests for LFV and LFUV with the ATLAS detector, using proton-proton collisions with a centre of mass energy of 13 TeV. A broad range of models and signatures are considered, including leptoquarks, heavy...
Recent LFV results from CMS
Rates of lepton-flavor violation in charged lepton decays are enhanced in many beyond-the-standard-model theories. The low-background samples of $e^+e^- \to \tau^+\tau^-$ events collected by Belle and Belle II allow world-leading searches for such decays with tau leptons. We present Belle II results for the decays $\tau \to \ell V^0$, where $V^0$ is a neutral vector meson, $\tau \to 3\mu$,...
The muEDM experiment at the Paul Scherrer Institute (PSI) aims to measure the muon's electric dipole moment (EDM) using the frozen spin technique. This approach involves storing muons within a solenoid and applying a radial electric field to counteract the spin precession caused by the anomalous magnetic moment. Any remaining longitudinal precession would indicate a non-zero EDM. The...
A storage ring proton electric dipole moment (EDM) experiment (pEDM) would be the first direct search for a proton EDM and would improve on the current (indirect) limit by 5 orders of magnitude. It would surpass the current sensitivity (set by neutron EDM experiments) to QCD CP-violation by 3 orders of magnitude, making it potentially the most promising effort to solve the strong CP problem,...
We propose here a set of new methods to directly detect light mass dark matter through its scattering with abundant atmospheric muons or accelerator beams. Firstly, we plan to use the free cosmic-ray muons interacting with dark matter in a volume surrounded by tracking detectors, to trace possible interaction between dark matter and muons. Secondly, we will interface our device with domestic...
The smallness of neutrino masses in conjunction with the observed flavor oscillations in the neutrino sector can be hinting to physics beyond the standard model. These observations can be naturally accommodated by the so-called "seesaw" mechanism, in which new Heavy Neutral Leptons (HNL) are postulated. Additionally, several HNL models provide a DM candidate or include a possible explanation...
I will discuss $\mu \rightarrow e$ conversion signatures stemming from light new physics at high-intensity muon experiments. Specifically, I'll focus on the discovery potential and reach of the $\mu \rightarrow 5e$ channel at Mu3e as well as the prospect of 'signal' electrons from muon-induced baryon number violation at Mu2e and COMET.
Dark Matter (DM) is one of the most interesting research topics in physics. Many particle physicists are trying to identify it because we know that dark matter is likely to be a major component of a complete fundamental description of nature. The Muon g-2 Experiment at Fermilab measures the anomalous precession frequency of the muon. Oscillations of this precession frequency could be produced...
Mu2e will search for coherent, neutrinoless conversion of muons into electrons in the nucleus field of aluminum with a sensitivity improvement of a factor of 10,000 over existing limits. Probing the charged lepton flavor-violating reaction at such sensitivity may uncover new physics at a scale unreachable by direct searches at current or planned high-energy colliders. The experiment...
Should muon-to-electron conversion in the field of a nucleus be found in the current generation of experiments, the measurement of the atomic
number dependence of the process will become an important experimental
goal. We present a new treatment of the (Z,A) dependence of coherent
muon-to-electron conversion in 236 isotopes. Our approach differs from
earlier work in several ways. Firstly,...
Mu3e is an experiment under construction at the Paul Scherrer Institute in Switzerland, aiming to search for the lepton flavour violating decay: mu+ -> e+e+e-. Any observation of this decay would indicate physics beyond the standard model (SM), as in the SM, neutrinos have no mass, and the decay is forbidden. Through extensions of the SM, the LFV decay becomes allowed through loops but is...
Charged lepton flavor violation (CLFV) is expected in a diverse set of new physics scenarios. The current generation of experiments in the muon sector probe CLFV in three complementary channels: muon to electron conversion (Mu2e, COMET), muon to electron and gamma (MEG-II), and muon to three electrons (Mu3e). These experiments aim to enhance existing limits by several orders of magnitude and...
This talk covers the status of the muon electric dipole moment search at the Fermilab Muon g-2 experiment. Electric dipole moments of fundamental particles violate CP, and are zero at tree level in the Standard Model, but significantly enhanced in many extensions of the SM. The Muon g-2 experiment is designed for a high precision measurement of the magnetic dipole moment of the (anti-)muon,...