14 April, 1994


Minutes of the tenth meeting held on Wednesday and Thursday, 6-7 April 1994


Present: J.V.Allaby, J.J.Aubert (Chairman), R.J.Cashmore, L.DiLella*, P.J.Dornan, P.Duinker, K.Einsweiler, F.Eisele, J.Ellis, L.R.Evans*, E.Fernandez, L.Foa, W.Hoogland, E.Iarocci, P.G.Innocenti, K.Kajantie, V.Khovansky, C.Llewellyn Smith*, G.W.London, G.Mikenberg, K.Potter, K.Pretzl, D.M.Sendall (Secretary), M.Turala, H.Wenninger*, D.O.Williams

*) Part time

Apologies: K.Schubert, S.Yamada

1. The minutes of the ninth LHCC meeting (LHCC 94-7 / LHCC 9) were approved without amendment.

2. C.Llewellyn Smith gave a brief summary of progress on the LHC project since the last LHCC meeting. It is hoped to get early approval for the project on the basis of the existence of "fall-back options" (involving a stretched timetable and possibly other undesirable elements) which do not require additional funding, in the hope that further discussions with non-member states will generate sufficient supplementary funding that these options will not need to be implemented. Further details will be presented to Council over the coming months. In the USA the HEPAP panel set up after the SSC cancellation has made a positive statement on co-operation, as have the Canadian authorities following the cancellation of KAON.


The referees had posed a number of questions (LHCC 94-3) concentrating on measurements of sin2alpha and xs, and based on a scenario for machine conditions in the first few years of LHC running.

P.Schlein presented the replies of the COBEX collaboration to the referees' questions (LHCC 94-14). These were based on a topology trigger for the first year's running and a single-muon trigger at higher luminosities.

T.Nakada presented the replies of the GAJET collaboration (LHCC 94-13). The use of an argon cluster jet was proposed for the first two years' running. Studies showed that this should not have serious effects on beam lifetime.

G.Carboni presented the replies of the LHB collaboration (LHCC 94-11). An alternative beryllium wire target is being considered particularly for low beam intensity running.

In the discussion, L.Evans pointed out that although crystal extraction is of great interest and studies will continue, it is not possible to say unequivocally that it will work.


F.Brasse gave a status report on the work of the CORE group. He presented the third report of the group (LHCC 94-12) on the B physics Letters of Intent. Only preliminary estimates are available in some areas, in particular for the magnets. However, the collaborations have been able to take advantage of the work on unit costs done for ATLAS and CMS. As a result, agreement on reasonable costs has already been reached in many areas. Further work remains to be done.

F.Brasse also presented a list of points which CORE wished to see covered by the ATLAS and CMS Technical Proposals. These include both common requirements and particular questions for each of the collaborations. The list will be further discussed at the next LHCC meeting.

On behalf of the LHCC, the Chairman thanked F.Brasse, who is retiring, for his valuable work as Chairman of the Costs Review Group. W.Bartel of DESY has agreed to be the new Chairman of CORE.


P.J.Dornan, E.Fernandez and J.Ellis reported on the work of the B physics referees. The collaborations had been able to respond to many of the referees' questions despite the limited time available. However, a number of concerns still need to be addressed, and the referees will discuss them further with the collaborations. The committee took note of the referees' report and agreed to discuss the matter again at the next meeting of the LHCC.


J.Schukraft presented the replies of the ALICE collaboration to the referees' questions (LHCC 94-15). He reviewed the interest of heavy ion physics at LHC and its relation to the fixed target ion programme and RHIC. Careful planning would be needed to share the resources of the community between these programmes.

L.Evans pointed out that although every effort would be made to permit parasitic pp running, success could not be guaranteed and dedicated running should be retained as a backup solution. Switching between pp and ions should in principle be straightforward.


G.London reported on the work of the ALICE referees. They had concentrated on pp parasitic running, Upsilon colour screening, and the strength of the collaboration.

K.Potter pointed out that from the machine point of view parasitic pp running should be understood to mean that ALICE would be prepared to accept conditions as they were, and not request machine operational changes which would disturb other experiments.

After discussion, the committee agreed on recommendations to be sent to the Director General for consideration by the Research Board. A copy of these recommendations is attached to the minutes.


R.Cashmore reported on the work of the CMS referees. He reviewed the current status of the collaboration, and progress towards the milestones on the inner detector, electromagnetic calorimeter and software.


F.Eisele reported on the work of the ATLAS referees. He reviewed progress on the barrel toroid, questions of access requirements, the current status of the muon chamber system, and optimisation of the inner tracker design.


J.Ellis reported on discussions with the Chairman and L.Di Lella. The basic programme of the LHC is now taking shape, and the number of available interaction points will be limited. The LHCC has already received several documents expressing interest in further physics topics (neutrino physics, sigmael / sigmatot, colour screening, other gas-jet experiments). The cancellation of the SSC means that no comparable experiments are likely to be done elsewhere, but new intellectual input is to be expected from the SSC community. A list of other possible topics has been drawn up, which will be circulated for comment and discussed at the next meeting of the LHCC. They include: unconventional top decays, non-perturbative electroweak effects, dark matter, effects suggested by recent cosmic ray experiments, monopole / quark or other searches, diffraction studies, gamma-gamma effects in heavy ion physics, and Pomeron-Pomeron effects in pp.

Suggestions from the community for other topics are welcome. They should be made informally as soon as possible to the Chairman, L.DiLella or J.Ellis. A number of speakers will be invited to cover the topics at an open session of the LHCC early in 1995.


J.Harvey reported on the work of the LHC Computing Review Board. He reviewed the LHC computing model, the proposed terms of reference of the LCRB, its relationship with other bodies, and the actions taken to date. He drew attention to the proposed software guidelines for the Technical Proposals (LHCC 94-16), which the LCRB had further discussed following the preparatory work of the COLLECT committee. The LHCC will consider these at their next meeting.

F.Bourgeois reported on preparations for setting up an LHC Electronics Review Board. He reviewed past experience and current efforts at co-ordination and rationalisation. The LERB should draw up recommendations in this area and could be advisory to the LHCC. The membership should represent a reasonably large number of institutes in the member states. A list of proposed members was given and a plan of work outlined: the LERB will meet first at the beginning of June. Improved communication between experiments and institutes is important: as a contribution to this a yearly workshop will be organised.


J.Ellis has received requests for guidelines on possible physics benchmarks for the ATLAS and CMS Technical Proposals. He presented a suggested list which will be circulated for comment and discussed at the next meeting of the LHCC.


7-8 June

30-31 August

9-10 November

The LHCC received the following documents*

o LHB Collaboration: Answers to the questions from the LHCC (LHCC 94-11)

o Cost Review Group: Third report of the Cost Review Group to the LHCC

(LHCC 94-12)

o GAJET Collaboration: Reply to the LHCC questions (LHCC 94-13)

o COBEX Collaboration: COBEX Status Report (LHCC 94-14)

o ALICE Collaboration: More questions from LHCC and the answers from ALICE (LHCC 94-15)

o J. Harvey: Suggested guidelines on computing for technical proposal (LHCC 94-16)

* Restricted circulation only.