Speaker
Description
The decay of free neutrons is a powerful tool for precision tests of the Standard Model of particle physics. Correlation coefficients - such as the beta asymmetry $A$ and the Fierz interference term $b$ - serve as input for the determination of the CKM matrix element $V_{\mathrm{ud}}$ and for searches for (effective) scalar and tensor as well as right-handed couplings.
The neutron decay spectrometer PERC (Proton Electron Radiation Channel), which is set up at the MEPHISTO beamline of the FRM II, aims to improve the accuracy of several correlation coefficients by up to one order of magnitude. PERC consists of a 12 m long superconducting magnet system, in which the neutron beam is contained by a non-depolarizing neutron guide. The magnetic field guides electrons and protons produced in the neutron decay towards the main detector, which will initially be a scintillation detector with photomultiplier tube readout. A second detector system, which consists of a scintillator read out by silicon photomultipliers, is installed in the upstream area of PERC and allows to identify backscatter events.
The poster gives an overview of PERC and presents the current status.
