L. Linssen, LCD monthly meeting, 25/3/2013 1

General news…

Monthly meeting, CLIC physics and detector study, 25 March 2013Lucie Linssen

Courtesy: Dominik Dannheim

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European strategy, latest newsThe strategy statements, which were made public at the end of January, underwent some small editing in statements f, l and q.(added word “long baseline”, added word “in Europe”, mentioning the preparatory group).Version discussed at last week’s SPC/council is attached to this meeting agenda.

Deliberation document by the ESG group is there to:• Rationale behind the scientific issues• Recommendations of the ESG Working Groups on the non-scientific issues => council

may consider taking up for future considerations

Below, an extract, just three slides out of 15 pages….More next time (document may not be public yet).

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Large-scale scientific activities, dCurrently the world’s leading laboratory at the high-energy frontier, CERN is Europe’s greatestasset in particle physics. Pushing further the high-energy frontier has been essential to tacklingmany of the most exciting questions in particle physics, and it is likely to remain so in thefuture. To stay at the forefront of particle physics, Europe needs to be in a position to proposean ambitious post-LHC accelerator project at CERN by the time of the next Strategy update.The process of preparing for future decisions on the next large project at CERN must be startednow, even though the physics output of the 2015-2017 full-energy run of the LHC will beessential to such decisions. The two most promising lines of development towards the new high energyfrontier after the LHC are proton-proton and electron-positron colliders. Focussed designstudies are required in both fields, together with vigorous accelerator R&D supported byadequate resources and driven by collaborations involving CERN and national institutes,universities and laboratories worldwide. The Compact Linear Collider (CLIC) is an electron positronmachine based on a novel two-beam acceleration technique, which could, in stages,reach a centre-of-mass energy up to 3 TeV. A Conceptual Design Report for CLIC has alreadybeen prepared. Possible proton-proton machines of higher energy than the LHC include HE6LHC, roughly doubling the centre-of-mass energy in the present tunnel, and V-LHC, aimed atreaching up to 100 TeV in a new circular 80km tunnel. A large tunnel such as this could alsohost a circular electron-positron machine (TLEP) reaching energies up to 350 GeV with highluminosity. In parallel with the technical design studies, the crucial R&D activities for assessingtheir feasibility include high-gradient accelerating structures in the case of CLIC and high-fieldmagnets in the case of HE-LHC and V-LHC. In parallel with this focussed R&D, Europe shouldalso pursue accelerator R&D programmes aimed at a broader scientific community. In thisregard, the TIARA project, which aims at developing a distributed Test Infrastructure andAccelerator Research Area in Europe, could play an important role.

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Large-scale scientific activities, e

There is also a strong scientific case for an electron-positron collider that could initially studythe Higgs properties with high precision, in a way complementary to the LHC, and later beupgraded to higher energy. Already at energies around 250 GeV, such a machine could performprecise and model-independent measurements of the Higgs branching ratios, with sensitivity tomost decay modes at the percent level. At energies around 350 GeV, such a machine couldperform precision tests of the top quark properties. At energies of 500 GeV and higher, such amachine could explore further Higgs properties, for example the coupling to the top quark, theself-coupling and the total width. It could also search for colour-neutral new particles, forexample some dark matter candidates that may have escaped detection at the LHC. TheJapanese initiative to offer to host the ILC opens a new window of opportunity in particlephysics. European groups have already made several crucial contributions to the recentlyCompleted Technical Design Report and are very interested in participating in the ILC project.Until now, it is the Japanese high-energy physics community that has expressed unanimoussupport for hosting the ILC in Japan. Nonetheless, much progress on the political side has beenreported to the ESG meetings and Europe thus need to be prepared in the event that the Japanesegovernment comes forward with a clear plan for hosting the ILC in Japan and invites Europe toparticipate.

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Organisational issues, l

It is a well-established practice in particle physics that experiments are conducted by acollaboration of institutes from all over the world and the cost of detector construction andoperation is shared by all participants. Accelerators, on the other hand, used to be built andoperated by a single national laboratory or by CERN. With the increasing cost of energy frontiermachines, it has become more and more difficult for a single country or for CERN onby itself to build such machines with their own resources alone. HERA and LHC are recentexamples where external partners contributed to the construction of accelerators by providingparts, expertise, and manpower. This model will become even more common in future energy frontiermachines, where the cost and effort for construction and - possibly - operation, willrequire collaboration on a global scale. After adopting the first Strategy in 2006, in March 2010,the CERN Council approved a set of statements as a framework for Europe’s possible futureparticipation in accelerator projects to be constructed globally………… continues over 1 more page, including various ideas (not just one) about organisation of Europe and CERN with respect to an ILC in Japan.

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Upcoming LC workshops and meetings

BNL (Snowmass) Energy Frontier meeting, at BNL, April 3-6http://www.bnl.gov/snowmass2103See next slides

FCAL meeting, Cracow, April 29 – May 1http://indico.cern.ch/conferenceDisplay.py?confId=225688

ECFA Linear Collider workshop, DESY, May 27-31 2013http://lc2013.desy.deWill soon proceed with collecting CLIC-related abstracts

EPS HEP, Stockholm, July 18-24http://eps-hep2013.eu/Planning to submit 2-3 CLIC-related abstracts

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CLIC detector and physicsinput to Snowmass process

Main meetings for us (with CLIC presence at all 3 meetings):Energy frontier meeting:

Brookhaven April 3-6Seattle, June 29 – July 6

Main Snowmass meeting:Minneapolis, July 29 – August 6

For the BNL meeting in April (attended by Frank and Lucie):- 3 short CLIC talks accepted on Higgs, top, BSM- Also still preparing input for EWSB session

CLIC physics white paper input to Snowmass in preparationForeseen for end May / early June

Editors nominated: Tomas Lastovicka, Lucie Linssen, Philipp Roloff, Andre Sailer, Frank Simon, Mark Thomson, James Wells(Some progress with the editing, following 2 editors meetings)

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=> Following the wish of the IB members => Use the new MoC situation to have an “author list” for the CLIC physics paper

http://indico.cern.ch/categoryDisplay.py?categId=4679

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LCD notes for reviewLCD-Note- Titles Author / comment

2012-006 Measurement of chargino and neutralino pair production at a 1.4 TeV CLIC collider

P. Roloff (possible update with additional bkg)

2012-010 Measurement of H -> tau tau at CLIC 1.4 TeV A. Munnich (final phase before release)

2012-012 Physics performances for Scalar Electron, Scalar Muon and Scalar Neutrino searches at √s=3 TeV and 1.4 TeV at CLIC

JJ. Blaising (finalising, incl. search in wide mass range)

2012-019 Measurement of H -> tau tau at CLIC @ 350 GeV A. Muennich (final phase before release)

2013-001 Measurement of the top Yukawa coupling at a 1 TeV International Linear Collider using the SiD detector

P. Roloff + J. Strube (finalising the text)

2013-002 Status Report on the Analysis of the 2011 CALICE W-AHCAL data A Lucaci-Timoce (finalising)

2013-004 Occupancy in the CLIC_ILD Time Projection Chamber using Pixelised Readout

M. Killenberg (nearly complete)

Help with reviewing is always welcome !

CLIC top paper now on arXiv:http://arxiv.org/abs/1303.3758Top quark mass measurements at and above threshold at CLIC