11 research outputs found
Measurement of the Proton Asymmetry (C) in free neutron β-decay with Perkeo III
The decay of polarized neutrons can be used to search for Physics Beyond the Standard Model.
The non-isotropic angular distributions of the decay particles are parity violating and reveal the true nature of the weak interaction.
Many observables are available in the decay of polarized neutrons, but the decay itself is only described by three parameters, which allows searches for new physics in a combined analysis.
Measurements of the electron angular correlation coefficient (A) can be used to precisely determine the ratio of the axial to the vector coupling constant.
The proton angular correlation coefficient (C) has only been measured once by a predecessor of this experiment.
We measured the proton asymmetry with a similar proton detector, but employed a new measuring scheme allowing the collection of the worlds first data on the proton energy dependence of the proton asymmetry.
At the current state of the analysis, a statistical uncertainty on the value of C of 0.8 % in each of the two detectors can be reached.
For a final value, studies of systematic effects based on field simulations and tracking are still missing.
For this measurement I designed and constructed a new detector. For the first time the scintillator was coated with a transparent conductive coating and together with the new CAD milled light-guides in a four-side readout configuration the low energy performance of the detector could be increased.
Several systematic effects have been studied, especially the Point Spread Function of the magnetic transport system
Design of the Magnet System of the Neutron Decay Facility PERC
The PERC (Proton and Electron Radiation Channel) facility is currently under
construction at the research reactor FRM II, Garching. It will serve as an
intense and clean source of electrons and protons from neutron beta decay for
precision studies. It aims to contribute to the determination of the
Cabibbo-Kobayashi-Maskawa quark-mixing element from neutron decay data
and to search for new physics via new effective couplings. PERC's central
component is a 12m long superconducting magnet system. It hosts an 8m long
decay region in a uniform field. An additional high-field region selects the
phase space of electrons and protons which can reach the detectors and largely
improves systematic uncertainties. We discuss the design of the magnet system
and the resulting properties of the magnetic field.Comment: Proceedings of the International Workshop on Particle Physics at
Neutron Sources PPNS 2018, Grenoble, France, May 24-26, 201
Bulk neutrinos and core collapse supernovae
We discuss the phenomenology of neutrino mixing with bulk fermions in the
context of supernova physics. The constraints on the parameter space following
from the usual energy loss argument can be relaxed by four orders of magnitude
due to a feedback mechanism that takes place in a broad region of the parameter
space. Such a mechanism also affects the protoneutron star evolution through a
non trivial interplay with neutrino diffusion. The consistency with the SN
1987A signal is discussed, as well as the implications for deleptonization,
cooling, composition of the neutrino flux and the delayed explosion scenario.Comment: 23 pages, 5 eps figures; v2: minor comments and references added,
version to appear on Phys.Rev.
Signatures of Supernova Neutrino Oscillations into Extra Dimensions
We consider the mixing of muon and tau neutrinos with sterile fermion fields
propagating in extra dimensions in the context of core collapse supernova
physics, extending the analysis of the electron neutrino case done in a
previous work. We show that the potentially dramatic modifications to the
supernova evolution are prevented by a mechanism of feedback, so that no severe
bounds on the parameters of the extra dimensions need to be imposed.
Nevertheless, the supernova core evolution is significantly modified. We
discuss the consequences on the delayed explosion mechanism and the
compatibility with the SN1987A signal. Then, for the cases of both nu_{mu,tau}
and nu_e mixing with bulk fermions, we analyse the distinctive features of the
signal on Earth.Comment: 16 pages, 7 figures; v2: minor changes, matches published versio
Design of the magnet system of the neutron decay facility PERC
The PERC (Proton and Electron Radiation Channel) facility is currently under construction at the research reactor FRM II, Garching. It will serve as an intense and clean source of electrons and protons from neutron beta decay for precision studies. It aims to contribute to the determination of the Cabibbo-Kobayashi-Maskawa quark-mixing element Vud from neutron decay data and to search for new physics via new effective couplings. PERC's central component is a 12 m long superconducting magnet system. It hosts an 8 m long decay region in a uniform field. An additional high-field region selects the phase space of electrons and protons which can reach the detectors and largely improves systematic uncertainties. We discuss the design of the magnet system and the resulting properties of the magnetic field