Muon capture on the proton and deuteron

Progress Report 2010 and Beam Request for 2011 Muon Capture on the Deuteron

A precision measurement of the rate of muon capture on the deuteron

Because quantum chromodynamics (QCD) is non-perturbative at low energies, strong interactions at the ∼ GeV scale are very challenging to understand. Theoretical progress has been made recently using QCD-based effective field theories (EFT). The short-distance physics of the effective theory is absorbed into a limited number of low energy constants (LECs), which are determined by direct experime...

Chiral effective field theory predictions for muon capture on deuteron and {3}He.

The muon-capture reactions {2}H(μ{-},ν{μ})nn and {3}He(μ{-},ν{μ}){3}H are studied with nuclear potentials and charge-changing weak currents, derived in chiral effective field theory. The low-energy constants (LECs) c{D} and c{E}, present in the three-nucleon potential and (c{D}) axial-vector current, are constrained to reproduce the A=3 binding energies and the triton Gamow-Teller matrix elemen...

Nuclear Muon Capture in Hydrogen and its Interplay with Muon Atomic Physics

The singlet capture rate ΛS for the semileptonic weak process μ+ p → n+ νμ has been measured in the MuCap experiment [2]. The novel experimental technique is based on stopping muons in an active target, consisting of a time projection chamber operating with ultra-pure hydrogen. This allows the unambiguous determination of the pseudoscalar form factor gP of the charged electroweak current of the...

Transverse Spin Effects at COMPASS

The measurement of transverse spin effects in semi-inclusive deepinelastic scattering (SIDIS) is an important part of the COMPASS physics program. In the years 2002-2004 data was taken by scattering a 160GeV/c muon beam off a transversely polarized deuteron target. In 2007, additional data was collected on a transversely polarized proton target. New preliminary results for the Collins and Siver...