WG.4: Particle and Nuclear Astrophysics and Gravitation International Committee (PaNAGIC)

Report on the IUPAP General Assembly 2002
Activities from 1998 to 2002

Present membership
Alessandro Bettini (Chair), Barry C. Barish, Massimo Cerdonio, Enrique Fernandez, Thomas K. Gaisser, Isabelle Grenier, Wick Haxton, Eckart Lorenz, Karl Mannheim, Victor Matveev, Arthur B. McDonald, John Peoples, Michel Spiro, Yoji Totsuka, Alan Watson,

1. The origins and the initial mandate
The committee was created by IUPAP in autumn 1998 to support international exchange of ideas and help in the convergence of the international scientific community in the large scale activities within the emerging fields of particle and nuclear astrophysics, gravitation and cosmology.

The Committee has 15 members, selected primarily on the basis of intellectual leadership and representing the major components of the field. One member is appointed by each of C4, C11, C12 and C19. One of the members acts as a link to AC2.

Substructures. In the original program it had been foreseen to appoint a subpanel in a particular subfield when this would be considered useful to help convergence of large scale international projects. In two sectors the need had been identified:

• Gravitational waves: The Gravitational Waves International Committee has been created by the interested community independently. GWIC had already expressed its willing to gather under the umbrella of PaNAGIC.
  
• Very Large Volume Neutrino Observatories. The need had been identified by the Taormina Workshop of the OECD MegaScience Forum in 1997.
  PaNAGIC committee should report to all of C4, C11, C12, C19, but the formal relationship should be with C4.
  This document contains:
  • The report on the four-year activity.
    
  • A self-assessment exercise and a proposal to continue.
    
  • A proposal for its constitution

2.1. Meetings
PaNAGIC has held five meetings:

• in Atlanta (US) on March 27-28 1999
• in Paris on Sept. 5 1999
• in Sudbury (Canada) on June 22, 2000
• at Gran Sasso National Laboratory (Italy) on September 12, 2001
• in Munich (Germany) on May 28, 2002

2.2. GWIC
The Gravitational Wave International Committee (GWIC) was formed, prior to the creation of PaNAGIC, when members of all gravitational waves experiments met in Paris in November 1997. The field of gravitational wave physics is a new and rapidly growing field with a number of major facilities being developed. The committee was formed because there was a need to develop good communication and co-operation between the projects around the world, especially with the construction of the large suspended mass interferometers. The committee consists of representatives of all the major initiatives in the world, both for resonant bars and for interferometers. More recently, a representation of the space based experiment, LISA and a theoretical representative have been added. Barry Barish presently serves as chair of GWIC. The committee was modelled after ICFA for particle accelerators, in order to create a forum for communication, sponsoring workshops, etc in this new field.
GWIC's membership includes representatives of all the interferometer detector projects (ACIGA, GEO, LIGO, TAMA, and VIRGO), acoustic detector projects (ALLEGRO, AURIGA, EXPLORER, NAUTILUS, and NIOBE), and space-based detector projects (LISA). GWIC meets regularly at least once a year in occasion of the Amaldi Conf., in the year this is held, and otherwise in occasion of other major meetings of the gw community.

When PaNAGIC was formed, GWIC was a natural body to serve as a subcommittee to PaNAGIC representing the field of gravitational wave physics and GWIC accepted the invitation to serve this role. GWIC has representation on PaNAGIC and reports regularly in both written and oral reports.

GWICs first accomplishment was to create a central biannual conference on the science of gravitational wave detection, as no such conference existed. The Amaldi Conference just had its fourth successful conference in Perth, Australia in July 2001 with 200 attendees, which for the first time was an IUPAP sponsored meeting. In addition, GWIC sponsors two workshops each year, one in detector development and one in data analysis techniques, which are small and international in location and participation.

GWIC serves as a forum for the directors of the major projects to meet annually and is very useful in that role. As a result, some international collaboration on R&D for future detectors (e.g. sapphire test masses) has developed. Equally importantly co-operation on data analysis has resulted for resonant bars, where published results have been produced. A joint data format has been decided for all gravitational wave detectors, allowing common data analysis. The ultimate aim is to create a true international network of gravitational wave detectors that can be used together as one scientific instrument.

2.3 HENAP
The Cherenkov detection of high-energy (>1 TeV) neutrinos in the deep sea or Antarctic ice promises to open an important new window onto the cosmos. The uncertainties in the current neutrino-rate calculations, the fragmentation of the interested community, and the high price tag of the future large size projects have raised a number of questions among scientists, funding agencies, and governments alike. Following the conclusions of the OECD Mega Science Forum workshop of Taormina in May 1997, PaNAGIC set up the High Energy Neutrino Astrophysics Panel (HENAP) with the following mandate:

• Firm up the scientific justifications: likely sources expected rates and their uncertainties, astrophysical importance of detecting such neutrinos, and connection with other astronomical observations.
  
• Establish the needed sensitivity and volume and examine the potential justifications for more than one site.
  
• Identify the needed steps to reach the required detector sensitivity, and establish the scientific milestones that should be reached by the successive generations of instruments, before proceeding to the next step.
  
• Define, with the scientists involved, the elements of comparison of the proposed technologies: performance, reliability, maintenance, cost effectiveness etc.
  
• Identify the opportunity for R&D collaboration between the various projects.
  
• Define the scientific and technical criteria for the choice of site(s) for a high-energy neutrino observatory.
  
• Suggest international collaboration guidelines.
  
• Examine the potential for involvement of industry
  
• Explore the benefit of the facilities for other fields of science.

The membership of HENAP consists of:Enrique FERNANDEZ (Spain) Chair, Steve BARWICK (US), John CARR (France), Charles DERMER (US), Friedrich DYDAK (CERN), Grigorii DOMAGATSKY (Russia), Emilio MIGNECO (Italy), Rene ONG (US), John PEOPLES (US), Leonidas RESVANIS (Greece), Yoji TOTSUKA (Japan), Eli WAXMAN (Israel)

HENAP has held four meetings, on March 10, 2001 in Venice, Italy, on September 7 and 8, 2001 in Gran Sasso National Laboratory of the INFN, also in Italy, in Laguna Beach (California) on November 28 and 29 2001, at Barcelona (Spain) on March 26-28, 2002 and, finaaly at Munich (Germany) on May 28, 2002. HENAP has produced its final report to PaNAGIC "High Energy Neutrino Observatories" on July 1st 2002. It is available at http://www.lngs.infn.it/site/exppro/panagic/section_indexes/frame_particles.html

In particular, the Report contains the following Recommendations:
"The observation of cosmic neutrinos with energies above a few hundred GeV will be of the highest scientific importance in that it will open an entirely new window to the most energetic phenomena in the Universe. Unlike charged particles, neutrinos point directly to the source of their production and provide unambiguous evidence for the acceleration of hadrons in those sources. Unlike photons, they can penetrate enormous amounts of intervening matter, thus providing a unique way to probe into the interior of known sources or to reveal new sources.

The feasibility of using deep water and polar ice as a detecting medium has been proven by the Lake Baikal experiment, and the AMANDA experiment at the South Pole, respectively. The experience of these projects also indicates that the technology to increase the size of the detectors to a km3-scale is now available. This is the scale where one can also reasonably expect, from theoretical models, to see high-energy neutrino signals from discrete astrophysical sources.

The cosmic-ray induced background limits high-energy neutrino detection to upward-going neutrinos that originate from the hemisphere opposite to that of the detector location. Complete coverage of the sky, which is important given the exploratory nature of these experiments, thus requires two detectors located in opposite Earth hemispheres.

The experiments are technologically challenging and will require the involvement of a number of industrial contractors. The sea experiments in particular will provide a testing ground for deployment of communication equipment and for the use of remotely operated vehicles, which are of interest to industry. The experiments also provide a platform for the deployment of measuring equipment for other scientific fields.

The scale of the experiments is very large and therefore requires a large number of scientists and engineers. The likely available resources and the number of scientists involved at present indicate the need for concentrating all the efforts in two distinct large projects, one in each hemisphere.
All the above considerations lead us to the following recommendations:

• Recommendation 1
  The observation of cosmic neutrinos above 100 GeV is of great scientific importance. Such neutrinos open a new window to the most energetic phenomena in the Universe and represent an opportunity for scientific discovery that should be pursued.
  From cosmic- and gamma-ray observations, we know that astrophysical processes accelerate particles to very high energies, extending to 1020 eV and above. There are good arguments to expect the production of high-energy neutrinos as well. Detecting such neutrinos is of high importance for three reasons:
  1. neutrinos provide unambiguous evidence for the cosmic acceleration of hadrons,
  2. neutrinos point directly back to their production site, and
  3. neutrinos can traverse all intervening diffuse matter in the Universe and reveal hidden sources.
     
• Recommendation 2
  The detectors should be of km3-scale, the construction of which is considered technically feasible.
  Conservative flux estimations from astrophysical sources imply that detectors with masses equal to or larger than 1 Gton should detect several neutrinos of energy 1 to 103 TeV per year. Even larger detectors may be required at higher energies. Plausible scenarios are being discussed where higher fluxes of TeV neutrinos are produced, leading to positive signals in smaller detector volumes.
  
• Recommendation 3
  The driving motivation for km3-scale neutrino detectors is the observation of cosmic point sources. For this purpose a complete coverage of the sky is an important goal, and thus a km3-scale detector in the Northern hemisphere should be built to complement the IceCube detector being constructed at the South Pole.
  Sources are not isotropically distributed in the local universe at redshift z << 0.1, and this, coupled with the likely small rates of potential sources, calls for a complete coverage of the sky. The Galactic center is of particular interest and only Northern hemisphere sites are able to see upward-going neutrinos from this region.
  
• Recommendation 4
  The existence of two detectors with different technologies is an important asset.
  Deployment and simultaneous usage of other detectors on the surface is easier in ice, while the reconstruction of Cherenkov light in water enables better angular resolution, and therefore potentially better pointing accuracy.
  
• Recommendation 5
  The scientific objectives of km3-scale detectors of cosmic neutrinos are strongly enhanced by contemporaneous observations of a broad spectrum of electromagnetic radiation, and thus it is important to set up coordination and communication between neutrino observatories and other major astronomy projects.
  The contemporaneous observation by neutrinos of point-like sources observed in other instruments with much better pointing accuracy will be decisive in the identification of the sources and the understanding of their physics mechanism. Lines of communication between the neutrino and photon communities should be established through joint scientific committees and meetings.
  
• Recommendation 6
  The km3-scale detector projects are unique facilities that should be open to all interested scientific teams who wish to contribute to their construction and exploitation.
  Opening the collaborations to world-wide participation is very desirable. The Northern hemisphere deep-water detector project should be open to all interested scientific teams from the outset. IceCube, which is already an international project, should examine possibilities for greater participation of other teams.
  
• Recommendation 7
  The km3-scale detectors should be regularly monitored by international peer-review.
  The projects should be monitored by regular peer-reviews of the scientific program, and of the engineering and managerial aspects.
  
• Recommendation 8
  Adequate planning to make the data collected by the detectors available to the scientific community is strongly encouraged.
  Large facilities in many fields of science are required to make their scientific data available to the scientific community at large. This requires considerable organization and resources, which should not be neglected in the planning of the experiments. In order not to lose the opportunities for data collection for broader dissemination, those interested in the data should get involved in the planning.
  
• Recommendation 9
  There is at this point no justification for more than one Northern hemisphere deep-water neutrino detector of km3-scale.
  Arguments for more than one detector in the Northern hemisphere stem from continuous coverage of the Southern hemisphere sky, and from the virtues of different detector technologies and different systematic errors. These arguments do not outweigh the advantages from pooling resources in a single, optimized detector.
  
• Recommendation 10
  The timely formation of an international collaboration for the construction and exploitation of a km3-scale Northern hemisphere deep-water detector is encouraged.
  The commitment of the scientists to build a km3-scale detector can start in the next few years. This commitment is needed to assemble an international collaboration with the required technical strength and to select the appropriate site for the detector. The start of construction should be set by the progress on the current-generation detectors (ANTARES, Lake Baikal and NESTOR). Valuable experience will be gained in the next few years from the development of instrumentation and from the deployment and operation in the sea by ANTARES, NEMO and NESTOR. The lessons learned from their efforts should be incorporated into the design of the km3-scale detector.

In its fifth meeting on May 28, 2002, PaNAGIC discussed on possible follow-on of the HENAP activities, after the presentation of the report to IUPAP. When presenting the final HENAP report at the PaNAGIC meeting in Munich, Fernandez recommended, on behalf of the HENAP committee members, to convene a meeting (in about one year or more from now) to facilitate cooperation on the Northern Hemisphere cubic kilometre array. He expressed the willingness of the HENAP members to act as the organising committee of that meeting. In June 2002, at the 7th meeting of the OECD Global Science Forum, A. Bettini advanced the proposal to present a report on the HENAP activity in the 8th meeting, foreseen for January 2003, and to discuss the possible contribution of the Organisation to the follow-on, in agreement with IUPAP.

2.4 General conference
PaNAGIC believes to be very important the existence of a common forum for the scientific debate amongst the different components of the field, to help the growth of a common culture. Rather than creating a new series, the Committee has decided to work with the organisers of the TAUP series to transform it gradually in the general conference for particle and nuclear astrophysics.

The first (biennial) issue has been TAUP 2001, held at Gran Sasso Laboratory on Sept. 8-12 2001. The Conference received the support of IUPAP through C4. The next issue, TAUP 2003, will be held in Seattle; http://int.phys.washington.edu

2.5 Schools
Under stimulation of PaNAGIC the Particle Astrophysics Winter School had been programmed by Eli Waxman and scheduled for January 2001 in Israel, but unfortunately could not take place for external reasons; the Erice International School of Cosmic Ray Astrophysics (Nov. 2000) was sponsored.

The PaNAGIC committee proposes IUPAP sponsorship for the Third Mexican School on Astrophysics, organized every two years with the aim to bring together young astrophysicists, nuclear and particle physicists interested in the interplay between those three areas.

PaNAGIC believes that the field needs still more high-level schools and looks forward to the possible organization at Erice of a School in fundamental particle and nuclear astrophysics.

2.6 WEB site
These actions are meant to create a set of data describing the field for reference both of scientific and of policy makers and to increase the public awareness on the science.

The WEB site has been created and is still under development in the site of the Gran Sasso Laboratory at http://www.lngs.infn.it/site/exppro/panagic/
It contains the following entries and subentries

• Mandate and membership
• Panels and Committees
  • Gravitational Waves International Committee (GWIC)           
    • Mandate      
    • Membership
      
    • Link to the GWIC site (independently developed)
• High Energy Neutrino Astrophysics Panel (HENAP)
  • Mandate
    
  • Membership
    
• Meetings (contains the notes of the past meetings)
  
• Statements
  
• Conferences and Workshops
  
  • Links to TAUP and Amaldi Conference
    
• Schools
  
  • Link to the Particle Astrophysics Winter School; Dead Sea, Israel December 2001
    
  • Link to the International School of Cosmic Ray Astrophysics; Erice (TP), Italy November 11 - 21 2001
    
• Particle and nuclear astrophysics
  
  • General public.
    
  • Scientific
    
  • The Science Report of PaNAGIC to IUPAP mentioned below at §2.8, containing a review of the status and perspectives of the science.
    
  • The HENAP report on High Energy Neutrino Observatories
    
• Laboratories and experiments.
  Laboratories and Experiments involved in the PaNAGIC project are sorted into eight different scientific areas. Each area contains an entry for each relevant experiment or laboratory including those in project or in the proposal status. The entry of each experiment or laboratory contains in a standardised format the description of the experiment including its status, its spokesperson, the collaboration etc.
  This section is near to completion.
  
  • Underground and underwater laboratories
    
  • Cosmic Rays
    
  • High energy gamma-ray astronomy
    
  • High energy neutrino astronomy
    
  • Nuclear astrophysics
    
  • Non accelerator neutrino physics
    
  • Particle cosmology
    
  • Gravitational Waves

2.8. The Science Report.
PaNAGIC produced in 2000 a Science Report containing a review of the ongoing experiments and future projects in the fields of particle and nuclear astrophysics and of particle related cosmology. The report was presented to the meeting of the Council and Commission Chairs of IUPAP in Beijing on 6 October 2000.

3. Self-assessment
The principal points in the PaNAGIC program and the status of their completion are the following

• Membership. PaNAGIC feels that the criteria originally taken to define the membership produced a working group competent in the different sectors of the field and well balanced.
  
• Meetings. Regularly hold one per year and well attended. Work through the e-mail between the meetings.
  
• GWIC. Its role as a forum for the directors of the major projects to meet annually and has been very useful. A joint data format has been decided for all gravitational wave detectors, allowing common data analysis. The pre-existing Amaldi Conference became the general conference of the area under the auspices of GWIC.
  
• HENAP. The HENAP meetings have provided a forum for the major experiments to discuss together in detail many technical and organizational points, and this has created a good basis for future discussions and possible convergence. The final report is an important document including both an in-depth review of the field and a set of recommendations for its development.
  
• Conferences. PaNAGIC helped in transforming TAUP series in the general particle and nuclear astrophysics conference. The process is well started and will gradually proceed.
  Schools for young scientists working in particle and nuclear physics, in astrophysics and in cosmology interested in the intersections of these areas are considered by PaNAGIC of great importance. Some actions have been done but more work is needed.
  
• WEB site. A large fraction is already in place and it has become a useful source of information both for the scientific community and the scientific Agencies.
  PaNAGIC feels that it has accomplished a large fraction of the work program set up at its start-up. The Science Report produced by PaNAGIC has already been useful to funding Agencies in the planning of their future actions in the field. The visibility of the field of nuclear and particle astrophysics has been increased by the actions of PaNAGIC.
  On the other hand much more work is needed in this emerging field and PaNAGIC seeks the approval by the IUPAP Council of a renewed mandate for a period of six years.

4. Proposed constitution

1. The mandate is to support international exchanges of ideas and to foster international cooperation in the pursuit of large scientific projects in the emerging fields of particle and nuclear astrophysics, gravitation, and cosmology, in particular in the sectors of
• The study of basic constituents of matter and their interactions by non-accelerator means.
• The study of the sources, acceleration mechanism and propagation of high energy particles in the Universe.
• The study of nuclear and particle properties and processes of astrophysical interest in the Universe.
• The study of gravity, including the detection and the astrophysical sources of gravitational waves.
2. The Committee has 15 members, selected primarily on the basis of intellectual leadership and representing the major components of the field. One member is designated by each of C4, C11, C12 and C19. The other members are nominated by PaNAGIC. One of the members acts as a link to AC2.
3. The Members of the Committee are appointed by the Council of IUPAP.
4. A member of the Committee is elected as its Chair by the members.
5. The term is three years and can be renewed for one consecutive one.