Research: Experiment - Overview
The experimental research projects carried out with participation
of this division at MPIK are
the reactor neutrino experiment
Double Chooz in Chooz in France,
the double beta decay experiment
GERDA at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy,
the Dark Matter search experiments
XENON100 and XENON1T at LNGS,
and the solar neutrino experiment
Borexino at LNGS.
Major progress has been achieved in all of these experiments during
Construction of the double beta decay experiment
GERDA in hall A of LNGS
has been completed. Gerda aims at measuring neutrino-less
double beta decay or at improving the current limits on the
life-time considerably. Observing this decay
would be of fundamental importance for neutrino physics and physics
beyond the Standard Model in general, because it would prove that
Lepton Number is not conserved by nature. It would show that neutrino
masses are not generated by the standard Higgs mechanism, which
provides charged fermions and quarks with mass. Potential consequences
go as far as the cosmological generation of the Baryon Asymmetry of
Similarly, the on-site installation of the neutrino oscillation
experiment Double Chooz at the
nuclear power station Chooz, France, is progressing. The far detector
has been completed and it has started data taking. The near detector
will be finished early 2012. Double Chooz will measure or limit
the last remaining and so far unknown lepton mixing angle.
Both theoretical models of flavour as well as indications from
global fits to all other existing data suggest that this angle
becomes measurable. The value of this angle has strong influence on
the future program of experimental neutrino physics, since it
decides if and how we can measure leptonic CP violation and the
neutrino mass ordering.
The division participates also in the
XENON100 Dark Matter search project
which started data taking already in 2010 and which obtained already
very important results. Data taking will continue and in parallel the
XENON1T project, an up-scaled version of the detector, is beeing
planned and realized. XENON100 and XENON1T make very important
measurements, since they cover a large part of the theoretically
expected parameter space for WIMPs, the favoured Dark Matter candidates.
The solar neutrino experiment
Borexino started data taking in 2007
and it has already obtained spectacular results. The achieved
radio-purity levels exceeded specifications by about one order of
magnitude, which allows much better measurements. The first direct
solar 7Be neutrino measurement was published already in
2007 and recent results include the observation of geo-neutrinos with
unprecedented precision, constraining the hypothesis of an active
geo-reactor in the Earth's core.
The arts of low-background physics,
which were developed in past and on-going experiments are unique.
The relevant techniques are further improved and new methods
are being developed for on-going and future experiments.