We study the prospects for excluding or discovering vectorlike leptons using
multilepton events at the LHC. We consider models in which the vectorlike
leptons decay to tau leptons. If the vectorlike leptons are weak isosinglets,
then discovery in multilepton states is found to be extremely challenging. For
the case that the vectorlike leptons are weak isodoublet, we argue that there
may be an opportunity for exclusion for masses up to about 275 GeV by direct
searches with existing LHC data at sqrt{s}=8 TeV. We also discuss prospects for
exclusion or discovery at the LHC with future sqrt{s}=13 TeV data.Comment: 36 pages. v2: references adde
We discuss the resummation of the Goldstone boson contributions to the effective potential of the Minimal Supersymmetric Standard Model (MSSM). This eliminates the formal problems of spurious imaginary parts and logarithmic singularities in the minimization conditions when the tree-level Goldstone boson squared masses are negative or approach zero. The numerical impact of the resummation is shown to be almost always very small. We also show how to write the two-loop minimization conditions so that Goldstone boson squared masses do not appear at all, and so that they can be solved without iteration.
Contents
This is one of the six reports submitted to Snowmass by the International Muon Collider Collaboration. The Indico subscription page: https://indico.cern.ch/event/1130036/ contains the link to the reports and gives the possibility to subscribe to the papers.The policy for signatures is that, for each individual report, you can subscribe as "Author" or as "Signatory", defined as follows:-"Author" indicates that you did contribute to the results documented in the report in any form, including e.g. by participating to the discussions of the community meeting, sending comments on the drafts, etc, or that you plan to contribute to the future work. The "Authors" will appear as such in on arXiv. -"Signatory" means that you express support to the Collaboration effort and endorse the Collaboration plans. The "Signatories" list will be reported in the text only.
We systematically study the modifications in the couplings of the Higgs boson, when identified as a pseudo Nambu-Goldstone boson of a strong sector, in the light of LHC Run 1 and Run 2 data. For the minimal coset SO(5)/SO(4) of the strong sector, we focus on scenarios where the standard model left-and right-handed fermions (specifically, the top and bottom quarks) are either in 5 or in the symmetric 14 representation of SO(5). Going beyond the minimal 5 L − 5 R representation, to what we call here the 'extended' models, we observe that it is possible to construct more than one invariant in the Yukawa sector. In such models, the Yukawa couplings of the 125 GeV Higgs boson undergo nontrivial modifications. The pattern of such modifications can be encoded in a generic phenomenological Lagrangian which applies to a wide class of such models. We show that the presence of more than one Yukawa invariant allows the gauge and Yukawa coupling modifiers to be decorrelated in the 'extended' models, and this decorrelation leads to a relaxation of the bound on the compositeness scale (f ≥ 640 GeV at 95% CL, as compared to f ≥ 1 TeV for the minimal 5 L − 5 R representation model). We also study the Yukawa coupling modifications in the context of the next-to-minimal strong sector coset SO(6)/SO(5) for fermion-embedding up to representations of dimension 20. While quantifying our observations, we have performed a detailed χ 2 fit using the ATLAS and CMS combined Run 1 and available Run 2 data.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.