CERN Accelerating science

  “TLEP” - Circular Higgs Factory and a Long-Term Perspective for High Energy Physics
  by Frank Zimmermann (CERN)

A long term strategy for particle physics. The succession of TLEP & VHE-LHC could provide more than 50 years of e+e-, pp, AA, ep/A physics at highest conceivable energies. The sequence LEP3 & HE-LHC represents a less ambitious, but lower-energy alternative.s. Image credit: TLEP.

Following the first EuCARD “LEP3 Day” on 18 June 2012 (see article ‘Circulating ideas about a new Higgs factory’ inAccelerating News issue 3), which revealed a great interest in a circular-collider “Higgs factory”, EuCARD Work Package 4,AccNet, has been organizing several workshops discussing the key ingredients, the physics potential, experimental detector concepts, and synergies with other projects of such a facility.

Emphasis has shifted from LEP3, a machine installed in the 27-km LHC tunnel originally proposed, to TLEP, an electron-positron collider in a new 80 or 100-km long ring tunnel. Advantages are manifold: TLEP construction would be fully decoupled from LHC/HL-LHC operation. TLEP could achieve up to 5 times higher luminosity than LEP3, promising a precision for Higgs coupling measurements much better than any other planned or proposed machine. Such precision is needed to discover physics beyond the standard model at energies above 1 TeV. In addition, TLEP could possibly provide the infrastructure (tunnel, cryogenics, injector-ring magnets, detectors) for a future 100-TeV proton-proton collider in the same tunnel – the “Very High Energy LHC” or “VHE-LHC” –, paving a path towards extremely high hadron collision energies, while also allowing for highest-energy electron-proton collisions.

Presently a TLEP conceptual design study is being set up aiming at delivering a design report by 2014/2015.