A characterisation of scintillating fibres with silicon photomultiplier read-out was performed in view of their possible application in fibre tracking detector systems. Such a concept is being considered for the Kaos spectrometer at the Mainz Microtr
on MAMI and as a time-of-flight start detector for the hypernuclear physics programme at the PANDA experiment of the FAIR project. Results on particle detection effciency and time resolution are discussed. In summary, the silicon devices are very suitable for the detection of the low light yield from scintillating fibres insofar a trigger scheme is found to cope with the noise rate characteristics.
We study the gauge covariance of the fermion propagator in Maxwell-Chern-Simons planar quantum electrodynamics (QED$_3$) considering four-component spinors with parity-even and parity-odd mass terms both for fermions and photons. Starting with its tr
ee level expression in the Landau gauge, we derive a non perturbative expression for this propagator in an arbitrary covariant gauge by means of its Landau-Khalatnikov-Fradkin transformation (LKFT). We compare our findings in the weak coupling regime with the direct one-loop calculation of the two-point Green function and observe perfect agreement up to a gauge independent term. We also reproduce results derived in earlier works as special cases of our findings.
Measured response functions and low photon yield spectra of silicon photomultipliers (SiPM) were compared to multi-photoelectron pulse-height distributions generated by a Monte Carlo model. Characteristic parameters for SiPM were derived. The devices
were irradiated with 14 MeV electrons at the Mainz microtron MAMI. It is shown that the first noticeable damage consists of an increase in the rate of dark pulses and the loss of uniformity in the pixel gains. Higher radiation doses reduced also the photon detection efficiency. The results are especially relevant for applications of SiPM in fibre detectors at high luminosity experiments.
New results of a Programme of study of BAL + IR + Fe II QSOs (at low and high redshift) are presented. Which are based mainly on deep Gemini GMOS integral field unit (IFU/3D) spectroscopy. We have performed a detailed study of the kinematics, morphol
ogical, and physical conditions, in the BAL + IR + Fe II QSO: IRAS 04505-2958. From this study, some selected results are presented, mainly for the 3 expanding giant shells (observed with Gemini). In particular, the GMOS data suggest that the outflow (OF) process -in this IR QSO- generated multiple expanding hypergiant shells (from 10, to 100 kpc), in several extreme explosive events. These new Gemini GMOS data are in good agreement with our evolutionary, explosive and composite Model: where part of the ISM of the host galaxy is ejected in the form of multiple giant shells, mainly by HyN explosions. This process could generate satellite/companion galaxies, and even could expel a high fraction -or all- the host galaxy. In addition, this Model for AGN could give important clue about the physical processes that could explain the origin -in AGNs- of very energetic cosmic rays, detected by the P. Auger Observatory.
