The FELIX collaboration had proposed the construction of a full-acceptance detector for the LHC. The primary mission of FELIX was the study of QCD: to provide comprehensive and definitive observations of a very broad range of strong-interaction processes. This document contains an extensive discussion of this physics menu. In a further paper the FELIX detector will be reviewed.
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HISTORYWith the advent of the large hadron collider (LHC), we are on the threshold of a new era in high-energy physics. With instrumentation in the form of dedicated experiments of unprecedented precision and complexity, the LHC will move significantly beyond the current high-energy frontier, and dramatically improve our understanding of particle physics at the highest energies and shortest distances accessible to man.As currently planned, however, the LHC experimental programme is incomplete. Moreover, these deficiencies continue and extend what has been a gap in the experimental programme of all hadron colliders. The problem lies in the design of the detectors instrumenting hadron colliders: they are all optimized for rare, high-pt events. These 'general purpose' detectors are anything but that. Rather, they are designed to explore extreme shortdistance phenomena. Without intending to demean the efforts of the collaborations which have built or are building these detectors, it is nevertheless these events in which the theorists are most confident that they understand the physics, and are in many ways experimentally most accessible.While there is no doubt that such physics and such detectors should be the centrepiece of any programme of hadron collider physics, it seems much less clear that they should be the only item on the agenda. Indeed, it can be argued that a full-acceptance detector, capable of detecting and measuring each particle in an event well, may have the greatest discovery potential. Alas, the absence of any experimental effort in this direction in the collider era has meant that both theoretical investigations and experimental design of such detectors has languished, to the point that many in the community have come to think of high-pt physics as the last frontier in particle physics.The FELIX collaboration sought to rectify this situation. With support from the CERN administration, some 160 physicists collaborated in preparing the FELIX LoI. Many of these could not officially join the collaboration, and so their help could only be acknowledged. While the FELIX proposal was never officially killed, it was nevertheless effectively killed without the collaboration making a formal presentation to the LHC committee.All of this, of course, is history, and not very pleasant history at that. The motivation for a full-acceptance detector remains, however, and interest on the part of the broader community, despite the implications of this history, remains high. Because of this, the FELIX collaboration, together with those who helped but were not members, believes that it is important to document the physics of a ...
