1. Marco Cattaneo, Aleph plenary, 23rd April 19981 Long term archive of LEP data  LEPC working group report Purpose Assumptions Conclusions  Physics goals  Options for Aleph Archive strategies Ownership of data Discussion ( -> steering committee)

2. Marco Cattaneo, Aleph plenary, 23rd April 19982 LEPC working group  Purpose: Study issues pertaining to long term (~30 years) archival of LEP data Archive should allow future analysis based on new experimental or theoretical input Aleph represented by J.Carr, M.Cattaneo  Assumptions: Several cycles of obsolescence for physical media FORTRAN libraries (CERNLIB,GEANT3) no longer supported Existing software (Galeph,Julia,Alpha,Scanbook) no longer runnable in the long term

3. Marco Cattaneo, Aleph plenary, 23rd April 19983 Working group conclusions (report to LEPC, 31st March)  Storage medium/model as for LHC expts. Objectivity/DB Further migration to new media ~ transparent  Simulation and reconstruction cannot be redone Requires too much “lost” expertise No point saving raw data Existing MC data AND corresponding generators must be saved  Identify and save all “meta”data Scanbook, Run selections, ADBS, DDL etc.  Save all documentation Algorithms, source code  Verify correctness and completeness of archive Redo simple analysis without using existing software!

4. Marco Cattaneo, Aleph plenary, 23rd April 19984 WG conclusions (2)  Resources needed (NEW manpower) For migration: Requires experienced people One person year per experiment One or two person years from IT Maintenance of archive One person from IT Licences, storage media  Ownership of data Who has access, who can publish, what is author list? Collaborations must decide while they are still active

5. Marco Cattaneo, Aleph plenary, 23rd April 19985 Physics goals  LEPC wants experiments to agree on physics goals of this archive (Meeting 2nd June LEPC+spokespersons) “Simple” QCD-like analysis using quantities such as momentum 4-vectors, energy-flow objects Does not require full data sets of all 4 experiments Search for newly discovered particles that “should have been seen at LEP” Without new signal MonteCarlo New “complex” analysis Why not do it now? Something totally new Best to save and document data in its fullest detail

6. Marco Cattaneo, Aleph plenary, 23rd April 19986 Options for Aleph (1)  Do Nothing Data will become rapidly unreadable (~10 years from now) Programs and meta-data will be lost when Aleph computers are switched off Software will not run on new platforms Detailed knowledge on how to run analysis will be lost  Store simple 4-vector format Format has to be defined (energy flow objects?), documented, tested Simple analysis program has to be provided Minimal documentation needed Why Aleph?

7. Marco Cattaneo, Aleph plenary, 23rd April 19987 Options for Aleph (2)  Store MINI (+DST) and document Conversion BOS = Objectivity/DB, and simple verification exist Meta-data easily identified and saved in Objectivity DDL, Scanbook+ADBS, Alpha inputs Run selections should be documented from  Re-analyses of LEP1 reprocessed data  Ongoing analyses of LEP2 data MonteCarlo data can be easily documented Save current configurations of LEP2 generators Save configurations of future LEP1+LEP2 productions Finish and publish analysis algorithms note Save Fortran source codes for documentation Kingal, Galeph, Julia configurations for given production The “last” maintained version of Alpha (hard-coded knowledge of data) Most of the above requires minimal new effort if it is set up correctly and rapidly

8. Marco Cattaneo, Aleph plenary, 23rd April 19988 The icing on the cake  Provide OO analysis program Would verify completeness of archive Would make re-analysis “easy” Requires additional manpower Can a newcomer re-implement “Alpha” in C++?

9. Marco Cattaneo, Aleph plenary, 23rd April 19989 Ownership issue  Who has access to archived Aleph data?  Who approves publications?  What is author list?  One possibility: Publish as part of the archive a note of “complete instructions” on how to use data Allow full freedom (and responsibility) of publication to authors of new analysis with REQUIREMENT that the instructions note is referenced. No reference to Aleph Collaboration in author list  Decision should be made when setting up the archive

10. Marco Cattaneo, Aleph plenary, 23rd April 199810 Discussion  Options: Do nothing Save energy flow objects A few person-months of new effort (technical student?) plus physicist supervision Save & document full data-set (MINI+DST) As above, plus part-time coordinator and librarian to make sure ongoing analyses are well documented and all existing documentation is identified, completed, archived Also provide OO Alpha As above, plus one-two person years (someone who already has analysis experience)  If we do more than nothing: What resources do we request from LEPC? How do we control access?