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Nuclear Physics focuses on the study of the structure and dynamics of complex
systems of particles which build up hadrons and nuclei. Nuclear Physics
has also a broad spectrum of applications and a strong impact on other
fields of science, as presented in the 1994 NuPECC report on «Impact
and Applications of Nuclear Science in Europe». Nuclear Science remains
fundamental for the development of future energy technologies. A number
of complementary research facilities in the field of Nuclear Physics are
established in Europe and are operated mainly by national institutions,
funded by national agencies and used by an international community of scientists.
The exploitation of this network of facilities is co-ordinated by international
advisory boards. This co-ordinated approach has led to a remarkable scientific
productivity and coherence in the field. It is therefore very important
to maintain the open access to this network. Future facilities and detectors
will considerably exceed today's systems in size, complexity and cost and
will mostly have to be realised in the framework of international collaborations.
NuPECC therefore recommends that national funding agencies should become
involved already during the planning stage of these new facilities. NuPECC
is ready to help in this process. For certain projects such as second
generation radioactive ion beam facilities and a future high-energy electron
accelerator the necessary steps should be taken soon.
Progress in Nuclear Physics depends not only on a
strong experimental programme but also on the excellence of research in
Nuclear Theory. NuPECC therefore recommends that universities and research
institutes assure the future of this part of the field by appointing young
scientists in Nuclear Theory. The European Centre for Theoretical Studies
in Nuclear Physics and Related Areas (ECT*) in Trento provides a forum
for the discussion of new ideas between theorists and experimentalists.
NuPECC recommends that long term financial support for ECT* from European
sources be assured.
NuPECC emphasises that universities throughout Europe play a key role
for the future of Nuclear Physics, both by providing the basic nuclear
physics education and the interface to other disciplines and by being the
home base for groups doing experiments at large facilities. NuPECC recommends
that the strength of the university home base be maintained.
Nuclear Structure under Extreme
The understanding of Nuclear Structure has made significant progress in
the last decade and, at the same time, has generated a number of challenging
new questions. They address the properties of the nucleus at the limits
of excitation energy, spin, isospin and mass. The rapid development of
experimental techniques leading to highly efficient detector arrays for
gamma-rays, charged- and neutral particles makes the investigation of central
issues of Nuclear Structure possible. These include extreme nuclear shapes
and their evolution as well as the influence of the thermal environment
on collective modes at low and high excitation energy. The next generation
of radioactive ion beam facilities will open the way to the study of new
Nuclear Structure phenomena near the drip lines, such as halo nuclei, neutron
skins, neutron-proton pairing and exotic collective phenomena. At the same
time, they will provide more insight into the process of nucleosynthesis.
Extrapolating from the recent observation of element Z=112, the
synthesis of superheavy elements near the expected island of stability
will become within reach with the new generation of high luminosity facilities.
Nuclear Structure studies rely on a continuing
availability of accelerators providing high quality beams of stable ions
and electrons. In order to fully exploit the important recent investments
in facilities and instruments, those accelerator laboratories which form
a European network of complementary facilities must therefore be supported
and further improved.
Nuclear Structure studies at the limits of stability
require the highest possible luminosities and detection efficiencies. The
European collaborations involved in the development of powerful new detector
systems and the operation or the construction of the radioactive beam facilities
and the R&D on high power target-ion source combinations should be
strongly supported in order to reach this goal.
NuPECC recommendation: A study group should
be set up in order to investigate the main options for second generation
radioactive ion beam facilities in Europe.
and the Phase Transitions of Nuclear Matter
Collisions of atomic nuclei at intermediate and high energies address some
of the key questions of modern Nuclear Physics. They are the means to study
the phases of nuclear and hadronic matter as a function of temperature
and density of the system. Several phase transitions are under investigation.
At low density and temperature, the nucleus may ``multifragment'' and evaporate
into a cold gas of nucleons and light nuclei. At high density and temperature,
hadronic matter may dissolve into the quark-gluon plasma via the associated
phase transitions of deconfinement and of chiral symmetry restoration.
At energies and densities below this regime, the equation of state of hot
and dense hadronic matter may be mapped out. The quark-gluon plasma phase
transition and the equation of state of dense matter are of astrophysical
and cosmological relevance, e.g. for the recreation of the conditions as
they existed about a microsecond after the Big-Bang, the structure of neutron
stars and the evolution of supernovae.
All these experimental activities must be accompanied
by theoretical investigations using teraflop computer systems. Recent advances
in parallel computer systems offer the opportunity to carry out the necessary
In order to investigate the phase transitions
of Nuclear Matter, the complementarity in energy and the variety of beams
of existing facilities should be maintained and existing detectors further
NuPECC recommendations: A study group should
be set up in order to investigate the possibility of a European effort
towards large scale computing. The realisation of a dedicated
heavy ion detector in time for the start of the LHC is endorsed as the
highest priority of the high-energy heavy ion community.
Quark and Hadron Dynamics
The study of the structure of baryons and mesons in terms of the quark
and gluon degrees of freedom offers many new challenges that Nuclear Physics
will have to address during the coming decade. Achieving a quantitative
treatment of the confinement regime, which cannot be treated perturbatively,
is at the basis of a more fundamental description of nuclei in terms of
elementary constituents and interactions. At the same time the understanding
of quark degrees of freedom is indispensable for the study of Nuclear Matter
under extreme conditions such as they occur in the quark-gluon plasma and
in astrophysical objects. Addressing the quark and gluon degrees of freedom
requires the development of new theoretical concepts and the investigation
of observables through exclusive measurements. The corresponding experiments
require high-energy high duty cycle lepton beams of a luminosity much beyond
the ones presently available.
High precision measurements at low energy making
the best use of existing facilities using electromagnetic and hadronic
probes remain essential.
For the time being, the study of the hadron and
quark dynamics at higher energy should be pursued with priority at the
existing facilities in Europe and in the US.
NuPECC Recommendation: As a new initiative,
a high luminosity and high duty cycle electron facility of at least
for fixed target experiments) should be built.
Nuclear and Particle Astrophysics,
Neutrino Physics, Fundamental Interactions
The impact of Nuclear Physics on other fields of science is particularly
strong for Astrophysics, Neutrino Physics, and the study of Fundamental
Interactions. The knowledge of nuclear properties, in particular of exotic
nuclei, and of the nuclear equation of state plays a crucial role in the
understanding of many astrophysical objects or events, especially explosive
ones. High intensity low energy stable and radioactive ion beam accelerators
are essential tools for the measurements of cross-sections relevant for
astrophysical processes. Many of the highly sophisticated techniques used
to unravel the neutrino properties are common with Nuclear Physics. The
use of the Nucleus to study the fundamental interactions and their symmetries
implies a deep knowledge of this complex system and the utilisation of
Involvement of Nuclear Physicists in a number
of experiments on neutrino mass, double-beta decay and dark matter should
be supported, including the development of new techniques using cryogenic
and superconducting detectors. High intensity pion, muon and cold neutron
beams for the study of fundamental symmetries and rare decays should continue
to be available.
NuPECC Recommendation: An underground accelerator
for background free measurements of important astrophysical cross-sections
at thermal energies should be constructed.
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