Status and Implications of BSM Searches at the LHC

Abstract

The LHC has collided protons on protons at center-of-mass energies of 7 and 8 TeV between 2010-2012, referred to as the Run I period. We review the current status of searches for new physics beyond the Standard Model at the end of Run I by the ATLAS and CMS experiments, limited to the 8 TeV search results published or submitted for publication as of the end of February 2014. We discuss some of the implications of these searches on the existence of TeV scale new physics, with a special focus on two open questions: the hierarchy problem, and the nature of dark matter. Finally, we give an outlook for the future.

Excessive Higgs pair production with little MET from squarks and gluinos in the NMSSM

“…Lower bounds on the masses of sparticles have been obtained [1,2] which depend, however, on the sparticle decay cascades and hence on the complete sparticle spectrum. Recent summaries of bounds within various scenarios can be found in [3][4][5][6]. In particular, for similar squark 1 masses M q and gluino masses M g and decay cascades motivated by the Minimal Supersymmetric extension of the Standard Model (MSSM), ATLAS obtained M q ∼ M g > ∼ 1.7 TeV [7].…”

Dark matter and the Higgs in natural SUSY

“…Hu . Following [53,54], we define the measure of fine-tuning to be: where δm 2 Hu is the running of m 2 Hu due to the new fields…”

“…The Higgs mass at tree-level in the MSSM is famously bounded by m Z , and relying on radiative corrections from stops and other particles in the MSSM forces the stops to be either at least ∼ 10 TeV or their A-terms to be multi-TeV (for recent reviews and original references, see e.g. [1][2][3]). Together with the null direct search results at the LHC, this puts the fine-tuning in the MSSM at the percent level or worse.…”

“…Second, we differ from the singlet-doublet DM models in that we are supersymmetrizing everything. 2 A priori, the parameter space of the entire model (MSSM+dark sector) is vast, but most of the soft parameters do not play a significant role in the analysis. As seen in (1.1), our dark sector only couples directly to the Higgs sector and the EW gauge sector of the MSSM.…”