Perspectives of Nuclear Physics in Europe - European Science ...

determination of abundance patterns, etc.). Dedicated
efforts aimed at the identification of presolar nova oxide
and SiC grains should be encouraged.
For X-ray bursts, it is critical to assess whether some
mass ejection may result from late radiation-driven
winds. Additional theoretical work is needed to determine
the likely nucleosynthesis endpoint in these sources.
Challenging high-resolution spectroscopy should be
pursued to solve the existing controversy associated
with the potential identification of absorption lines, as a
way to constrain nucleosynthesis.
The contribution of Big Bang to the abundance pattern
is rather well known. The remaining uncertainties,
such as the 7 Li problem, will require a multidisciplinary
approach, including theoretical work on the contribution
of non-thermal processes (cosmic ray spallation reactions)
and of additional astrophysical sources (classical
novae, type II supernovae) to the synthesis of 7 Be ( 7 Li),
and key observations of lithium in extremely metal poor
stars of the Galactic halo.
The important role of low- and intermediate-mass
stars in element synthesis (s-process) would require
improvement of the theoretical models (most likely in a
multidimensional framework), in areas such as convective
and non-convective (magnetically driven) mixing and
dredge-up, tightly connected with the formation of the
required 13 C pocket, mass loss and rotation. This will
benefit from high-resolution spectroscopic studies of
intermediate-mass stars in different stages (from Main
Sequence to the AGB phase) and in different environments,
both in our Galaxy (halo, globular clusters…)
and extragalactic.
For supernovae, theoretical efforts should focus
on the determination of the burning flame regime and
the likely transition from deflagration to detonation in
type Ia models, and on the mechanism that drives the
explosion (spherical or asymmetric) in type II models,
including a better characterization of the neutrino transport,
Multidimensional models are certainly required to
address such issues, combined with high-resolution
spectroscopy and panchromatic observations (X-ray,
γ-rays…) to address other key features, such as the
possible metallicity dependence of SNIa and its link
with the cosmological applications of thermonuclear
supernovae. Studies of laboratory X-grains condensed
in the ejecta from (type II) supernovae can also play an
important role in this field, and a tight connection with
the cosmochemistry community will be required.
Much theoretical effort will be required to address
some of the fundamental questions that remain to be
solved for neutron stars, in areas such as the equation
of the state, and a number of exotic properties such as
superfluidity. This work would benefit from high-resolution
spectroscopic analyses of absorption atomic lines
that may help to derive the M-R relationship and, in turn,
put constraints on the predicted strange quark stars.
Combined observational and theoretical studies of the
cooling of neutron stars will aid a better understanding
of the nature of the neutron star interior.
Priorities
1. Nuclear astrophysics, perhaps uniquely, requires
access to an extremely wide range of stable and radioactive
beams and often involves very long periods
of beamtime. It is vital to maintain and enhance the
existing network of complementary facilities that have
been developed through past coordinated efforts in
Europe, from the small university based to the large
national laboratory based, to satisfy the increasing
demand for these beams and to provide the essential
time for instrument development and student training.
This is the priority for the period through to 2015 and
beyond.
2. Along with the nuclear structure community (WG3) the
nuclear astrophysics community is eagerly awaiting
the completion of the next generation of radioactive
beam facilities (FAIR, SPIRAL 2, HIE_ISOLDE and
SPES) which will provide a rich variety of complementary
beams needed to tackle more complex issues.
This work will become important during the period
2015-2020. The later three facilities are the precursor
to EURISOL, which will be developed in the following
decade.
3. During the period 2010-2015 it will be essential to
select and construct the next generation of underground
accelerator facility. Europe was a pioneer in
this field, but risks a loss of leadership to new initiatives
in the USA. Providing an underground multi-MV accelerator
facility is a high priority. There are a number of
proposals being developed in Europe and it is vital
that construction of one or more facilities starts as
soon as possible.
4. The small reaction yields typical of the field mean
that high beam currents and extremely sophisticated
experimental approaches are required. Towards the
end of the decade a high intensity facility as envisaged
in the ECOS proposal will be required to enable the
nuclear astrophysics community to pursue the more
challenging reaction measurements that are at present
our of experimental reach.
5. Efforts must be made to strengthen the coordination
between the nuclear physicists, astrophysical
modellers and astronomers engaged in the field. The
recently approved EuroGENESIS EUROCORES pro-
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