No Arabic abstract
Two next-generation high-energy experiments, the Large Hadron Collider (LHC) and the $e^+e^-$ International Linear Collider (ILC), are highly expected to unravel the new structure of matter and forces from the electroweak scale to the TeV scale. In this talk we give a compelling but rather descriptive review of the complementary role of LHC and ILC in drawing a comprehensive and high precision picture of the mechanism breaking the electroweak symmetries and generating mass, the unification of forces and the structure of spacetime. Supersymmetry is exploited in this description as a prototype scenario of the physics beyond the Standard Model.
In view of the very precise measurements on fermion couplings which will be performed at ILC250 with polarized beams, there is emerging evidence that the LEP1/SLC measurements on these couplings are an order of magnitude too imprecise to match the accuracies reachable at ILC250. This will therefore severely limit the indirect sensitivity to new resonances and require revisiting the possibility to run ILC at the Z pole with polarized electrons. This work was done as a contribution to the ESU 2018-2020.
If the cold dark matter consists of weakly interacting massive particles (WIMPs), anticipated measurements of the WIMP properties at the Large Hadron Collider (LHC) and the International Linear Collider (ILC) will provide an unprecedented experimental probe of cosmology at temperatures of order 1 GeV. It is worth emphasizing that the expected outcome of these tests may or may not be consistent with the picture of standard cosmology. For example, in kination-dominated quintessence models of dark energy, the dark matter relic abundance can be significantly enhanced compared to that obtained from freeze out in a radiation-dominated universe. Collider measurements then will simultaneously probe both dark matter and dark energy. In this article, we investigate the precision to which the LHC and ILC can determine the dark matter and dark energy parameters under those circumstances. We use an illustrative set of four benchmark points in minimal supergravity in analogy with the four LCC benchmark points. The precision achievable together at the LHC and ILC is sufficient to discover kination-dominated quintessence, under the assumption that the WIMPs are the only dark matter component. The LHC and ILC can thus play important roles as alternative probes of both dark matter and dark energy.
The synergy between the Large Hadron Collider and the International Linear Collider during concurrent running of the two machines has the potential to maximise the physics gain from both facilities. Some examples of detailed case studies of the interplay between the LHC and ILC are given, with a particular emphasis on new results that have been obtained after the first LHC / ILC Study Group report was released.
The prospects for the discovery and exploration of low-energy Supersymmetry at future colliders, the Large Hadron Collider (LHC) and the future international linear electron positron collider (ILC) are summarized. The focus is on the experimental techniques that will be used to discover superpartners and to measure their properties. Special attention is given to the question how the results from both machines could influence each other, in particular when they have overlapping running time.
Physics at the Large Hadron Collider (LHC) and the International e+e- Linear Collider (ILC) will be complementary in many respects, as has been demonstrated at previous generations of hadron and lepton colliders. This report addresses the possible interplay between the LHC and ILC in testing the Standard Model and in discovering and determining the origin of new physics. Mutual benefits for the physics programme at both machines can occur both at the level of a combined interpretation of Hadron Collider and Linear Collider data and at the level of combined analyses of the data, where results obtained at one machine can directly influence the way analyses are carried out at the other machine. Topics under study comprise the physics of weak and strong electroweak symmetry breaking, supersymmetric models, new gauge theories, models with extra dimensions, and electroweak and QCD precision physics. The status of the work that has been carried out within the LHC / LC Study Group so far is summarised in this report. Possible topics for future studies are outlined.