Townhall Meeting - 18 August 2005
The case for two detectors
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In response to Barry Barish's request, the World Wide Study asked a panel of Jim Brau, Tsunehiko Omori, Ron Settles, with Joel Butler as reviewer, to present a report on the case for two detectors at the ILC to a town meeting of a few hundred people on Thursday afternoon.
The group presented six classes of reasons in support of two detectors, a set of possible arguments against two detectors, and proposed a set of scenarios for costing to move the debate forward.
Jim Brau noted that the decision on the number of detectors is not yet urgent and that the discussion will continue for some time. But Barish commented that "it is better to work this problem now rather than later...so that by the time there become money issues, we have our arguments in hand."
In response to the document, Barish highlighted one important missing element from the analysis: the separation of two interaction regions from two detectors, which could conceivably be alternated in one interation region. All options should be clearly differentiated and resolved, he said. Barish said this issue is "as significant, in terms of money, as to whether we have one tunnel or two."
Barish said that the case for two detectors looks strong but more needs to be done to convince him that the case for two interaction regions is as strong. He said that the group needs to form an answer to the question, "What is frill and what do we really need to come forward with a proposal?"
Extensive discussion followed, presenting more arguments for and against two interaction regions and detectors, and presenting different perspectives on the strengths of various arguments.
The meeting formed one step toward a resolution of the issue and, as Barish said, "We owe it ourselves [to debate this properly] because the interaction regions cost so much."