WHAT EXPERTS SAY
HERE IS THE OFFICIAL CERN POSITION ON THE POTENTIAL DANGERS ASSOCIATED WITH OPERATING THE LHC:
CERN/DG/Research Board 2003-347
Minutes-162
7 February 2003
ORGANISATION EUROPÉENNE POUR LA RECHERCHE NUCLÉAIRE
CERN EUROPEAN ORGANIZATION FOR NUCLEAR RESEARCH
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CERN RESEARCH BOARD
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MINUTES OF THE 162nd MEETING OF THE RESEARCH BOARD
HELD ON THURSDAY, 6 FEBRUARY 2003
Present : J. Äystö, J.-J. Blaising, M. Calvetti, R. Cashmore, C. Détraz, L. Evans, R. Forty (Secretary), Luis Alvarez Gaumé (replacing G. Altarelli), M. Hauschild, H. Hoffmann, J. Iliopoulos*, J. Kirkby*, K. Königsmann, P. Lebrun, L. Maiani (Chairman), J. May, S. Myers, G. Roy, J.-A. Rubio, W.-D. Schlatter, A.A. Watson*, C. Wyss, W. von Rüden, A. Zalewska
*part-time
Items
- Procedure
- Status Report on the Pierre Auger experiment (A.A. Watson)
- Reports and matters arising from the INTC meeting of 25 November 2002
- Study of possibly dangerous events during Heavy Ion collisions at LHC (J. Iliopoulos)
- Reports and matters arising from the LHCC meetings of 27-28 November 2002 and 29-30 January 2003
- Reports and matters arising from the SPSC meeting of 14 January 2003
- Any other business
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4. STUDY OF POSSIBLY DANGEROUS EVENTS DURING HEAVY ION COLLISIONS AT LHC
J. Iliopoulos reported on the study made by a committee that he chaired, concerning the possibility of producing dangerous events during Heavy Ion collisions at the LHC [8]. A previous study made for RHIC had concluded that the candidate mechanisms for catastrophe scenarios are firmly excluded by existing empirical evidence, compelling theoretical arguments, or both. Following their investigation, the committee concurred with this conclusion. They studied the possible production of black holes, magnetic monopoles and strangelets. They also reviewed the astrophysical limits, coming from interaction of cosmic rays with the moon (or with each other) which, under plausible assumptions, exclude the possibility of dangerous processes in Heavy Ion colliders.
Black holes produced in theories with extra, compact, dimensions, for which the fundamental scale could be as low as 1 TeV, might be copiously produced at the LHC. However, only extremely massive black holes, beyond the reach of any accelerator, would be stable. It has been speculated that magnetic monopoles might catalyze proton decay. At each catalysis event, energy is released by the decaying proton, causing the monopole to move. They estimated the number of nucleons that the monopole would destroy before escaping from the earth, and found it to be negligibly small.
Most of the committee’s study concerned strangelets, a hypothetical new form of matter containing roughly equal numbers of up, down and strange quarks. They may become dangerous if they can be produced at the LHC, are sufficiently long-lived, are negatively charged so that they can attract and absorb ordinary nuclei, and finally if they can grow indefinitely without becoming unstable. The committee found that, from general principles, if negatively-charged strangelets exist at all, they would not grow indefinitely: they soon become unstable. Furthermore they concluded that any hadronic system with baryon number of order 10 or higher is out of reach of a Heavy Ion collider, and the LHC will be no more efficient at producing strangelets than RHIC. To be dangerous the strangelet would need to be stable from very low baryon number, where production is possible, all the way up towards infinite baryon number, a possibility that has been excluded by the stability studies.
L. Maiani thanked J. Iliopoulos and his committee for their work, and the Research Board took note of the report.
PLEASE NOTE THAT THE OFFICIAL POSITION ASSUMES THE THEORY OF BLACK HOLE EVAPORATION IS CORRECT, EVEN THOUGH THERE IS NO EMPIRICAL EVIDENCE TO PROVE SUCH. THIS IS A FAITH-BASED POSITION IN THAT IT RELIES ENTIRELY ON THEORY THAT IS NOT SUBSTANTIATED BY EVIDENCE.