Review of speculative "disaster scenarios" at RHIC

This paper discusses speculative disaster scenarios inspired by hypothetica l new fundamental processes that might occur in high-energy relativistic he avy-ion collisions. The authors estimate the parameters relevant to black-h ole production and find that they are absurdly small. They show that other accelerator and (especially) cosmic-ray environments have already provided far more auspicious opportunities for transition to a new vacuum state, so that existing observations provide stringent bounds. The possibility of pro ducing a dangerous strangelet is discussed in most detail. The authors argu e that four separate requirements are necessary for this to occur: existenc e of large stable strangelets, metastability of intermediate size strangele ts, negative charge for strangelets along the stability line, and productio n of intermediate size strangelets in the heavy ion environment. Both theor etical and experimental reasons why each of these appears unlikely are disc ussed. In particular, the authors know of no plausible suggestion for why t he third or especially the fourth might be true. Given minimal physical ass umptions, the continued existence of the Moon, in the form we know it, desp ite billions of years of cosmic-ray exposure, provides powerful empirical e vidence against the possibility of dangerous strangelet production.