Overview of the Workshop
This NATO Advanced Research Workshop (ARW) dealt with the emerging field of "astroparticle physics", which constitutes a fusion of traditional astrophysics with modern particle physics, both theoretical and experimental. Researchers in the field gathered to exchange knowledge and information gained from recent experiments on non-accelerator particle astrophysics, which have brought many new important results, as well as a list of unanswered questions.

The possibility of neutrino oscillations, and therefore of non-zero neutrino masses, is one of the most interesting subjects in astroparticle physics; other topics of importance in cosmology and particle physics include: the origin of high-energy cosmic rays, the existence and nature of dark matter, magnetic monopoles, and other super-massive particles.

A wealth of information has been provided by the SuperKamiokande, MACRO, and Soudan 2 experiments regarding atmospheric neutrinos. These experiments have found a significant reduction with respect to expectation in the number of muon neutrinos that reach the earth, while the electron neutrinos agree with expectations. This has been interpreted as due to neutrino oscillations, but a final proof of this effect requires "appearance experiments", that is, the observation of the new neutrino type into which the muon neutrino has oscillated.

The workshop gave considerable emphasis to these subjects, with presentations of new experimental results, new proposed detectors, long baseline experiments, as well as phenomenological and theoretical interpretations.

Another main goal of this Advanced Workshop was to bring together a relatively small number (less than 50) physicists and astrophysicists involved in high-energy particle and astro-physics research in order to ignite discussions regarding the present and future directions taken by the field. Indeed, one of the prime achieve-ments of the workshop was that it gave all participants the opportunity to discuss the new results and try to draw guidelines for new developments in these fields, in relation with other fields. In three days, Oujda (the workshop group, but also the university community) was able not only to fuse seemingly disparate fields as cosmic rays, dark matter from gravitational collapses, supernovae, neutrinos from gamma-ray bursts, and cosmology, but also to connect Europe (and the rest of the West) with Morocco (and the rest of the South).

In a final collective burst of thought and discussion, the workshop organized a "round table" discussion, superbly directed by Paolo Lipari (National Institute of Nuclear Physics, Roma, Italy), on "the future of particle astrophysics research" and "opportunities for North-South cooperation in astroparticle physics." A summary of this final roundup is given below, and one of the contributions made to the discussion, that of Jamal Mimouni (University of Constantine, Algeria) and Nidhal Guessoum (American University of Sharjah, UAE), is presented separately.

We should also note that concurrent with the workshop, a short historical exhibition was organized by the French Institute for Oriental Culture, in connection with the bicentennial of the death of Luigi Galvani and the bicentennial of the invention of the battery by Alessandro Volta.

The workshop was sponsored by the NATO Science Programme, Mohamed 1st University (Oujda), Faculty of Sciences (Oujda), INFN sezione di Bologna and the University of Bologna.

The future of particle astrophysics research
In summarizing the themes of the conference, Paolo Lipari first noted that neutrino physics has come of age, with significant progress on the properties of these particles, their oscillations, their astrophysical sources (supernova watches), and their cosmological implications. The MACRO collaboration experiment has not discovered magnetic monopoles (though it has set limits on them), nor massive relics, but it has strongly established neutrino oscillation studies and set a rich future program for it; it also has not yet established muon astronomy, but it has opened the way for future underground research programs. In astrophysics, it has certainly developed into a new way of looking at the sky. The key question that has emerged in this area is: has neutrino physics opened a window on new physics (at high masses, i.e. > 3 GeV)? As far as future experiments are concerned, one should ponder carefully whether km3 detectors set the scale (and thus the solution) to begin probing astrophysical sources? If not, then what is the future for experimental neutrino astrophysics?

The field of "High Energy Astro-physics" has also witnessed several truly amazing discoveries in the past 10 years, from AGNs (Active Galactic Nuclei) and their interesting characteristics, to GRBs (Gamma-Ray Bursts) and their fascinating properties. And soon, with GLAST (Gamma-ray Large Area Space Telescope), another quantum leap will be achieved. GLAST will be able to detect 10 000 sources of high-energy radiation (E > 20 MeV), compared to 260 sources detected by the very successful EGRET (Energetic Gamma Ray Experiment Telescope, on board the late Compton Gamma Ray Obser-vatory, CGRO). The key question here is, Lipari asks: "Is this 'just' astronomy, or is it 'fundamental physics'?"

In his third "rapporteur" segment, Lipari addressed the topics of gravitational wave detection and cosmic rays. On the first, the major advances reported on by Barish, in particular, fill us with optimism and enthusiasm to the point that one inquires: "are we witnessing the coming out of the tunnel of this field", with all the major implications that this brings forth? On the second topic (cosmic rays), Lipari notes that the century-old problem of their origin remains open. After decades of experiments and models, we still have no answer to the "knee" (part of the spectrum) problem (How important is it? Does it point to "new physics"?), except to request more and more precise measurements of the cosmic ray spectrum as a function of nuclear composition. Moreover, the conflict between high-energy cosmic rays and the GZK (Greisen-Zatsepin-Kuz'min) effect (suppression of gamma rays of E >10 TeV over distances greater than 100 Mpc) remains a rather extra-ordinary problem.

Opportunities for North-South cooperation in astroparticle physics
In this illuminating discussion, the workshop participants first heard from Charles Peck and Francois Vanucci, who gave less than optimistic accounts about the prospects for astroparticle physics research in the "North". Peck first sounded an alarm: whereas particle physics one or two decades ago was attracting the best and the brightest student minds, it now faces very strong competition from biology (e.g. the Genome Project) and computing (the IT revolution). Vanucci confirmed this trend in France: the number of science students has dropped by a factor of 2 over the past 5 years!

In parallel to this trend, Vanucci provided another revealing and positive statistic: in France, of the 400 ex-perimental particle physicists today, 30 to 40% are doing research in "astroparticle physics" compared to 5-10% about a decade ago. It is thus clear that astrophysics is saving particle physics, after the dramatic slow down of accelerator-based discoveries (only the 3rd neutrino and the top quark can be listed in the past 15 years), while astrophysical or astroparticle discoveries keep growing and accelerating. This in itself constitutes good news for developing countries, as their scientists no longer need (costly) accelerators to conduct research in and contribute to particle physics.

The pressing question to be addressed is then: why this overall fleeing of minds from science in general and particle physics in particular? Why this ever-shrinking support for our research by society?

Charles Peck blames scientists for having failed to explain to youngsters what they are doing, thereby failing to attract them to research. In his view, it is more than ever important to provide guidance to undergraduate students. Moreover, with the marriage of particle physics with astronomy, it now becomes rather easy to "illustrate" the concepts and phenomena we astroparticle scientists are investigating; more than ever this "communication" task becomes a duty for us to perform.

For Francois Vanucci, the problem is one of perception (of science) by society at large. It used to be believed that knowledge leads to progress, which in turn leads to happiness. The link between knowledge and progress is no longer seen. Instead society relates science more and more to the ills of our civilization: pollution, global warming, radioactivity (Chernobyl), mad-cow disease, etc. Vanucci concurs with Peck: scientists must communicate more and better with society, without this this the umbilical cord will get trimmed until research dies of neglect. The "southern" point of view to this topic was addressed separately by Jamal Derkaoui (Oujda University) and by a combined piece from Jamal Mimouni (University of Constantine, Algeria) and Nidhal Guessoum (University of Sharjah, UAE). The latter contribution is presented elsewhere in this publication.