We perform an extensive survey of nonstandard Higgs decays that are consistent with the 125 GeV Higgs-like resonance. Our aim is to motivate a large set of new experimental analyses on the existing and forthcoming data from the Large Hadron Collider (LHC). The explicit search for exotic Higgs decays presents a largely untapped discovery opportunity for the LHC collaborations, as such decays may be easily missed by other searches. We emphasize that the Higgs is uniquely sensitive to the potential existence of new weakly coupled particles and provide a unified discussion of a large class of both simplified and complete models that give rise to characteristic patterns of exotic Higgs decays. We assess the status of exotic Higgs decays after LHC run I. In many cases we are able to set new nontrivial constraints by reinterpreting existing experimental analyses. We point out that improvements are possible with dedicated analyses and perform some preliminary collider studies. We prioritize the analyses according to their theoretical motivation and their experimental feasibility. This document is accompanied by a Web site that will be continuously updated with further information [http://exotichiggs.physics .sunysb.edu].
In the context of the MSSM the Light Stop Scenario (LSS) is the only region of parameter space that allows for successful Electroweak Baryogenesis (EWBG). This possibility is very phenomenologically attractive, since it allows for the direct production of light stops and could be tested at the LHC. The ATLAS and CMS experiments have recently supplied tantalizing hints for a Higgs boson with a mass of ≈ 125 GeV. This Higgs mass severely restricts the parameter space of the LSS, and we discuss the specific predictions made for EWBG in the MSSM. Combining data from all the available ATLAS and CMS Higgs searches reveals a tension with the predictions of EWBG even at this early stage. This allows us to exclude EWBG in the MSSM at greater than (90) 98% confidence level in the (non-)decoupling limit, by examining correlations between different Higgs decay channels. We also examine the exclusion without the assumption of a ≈ 125 GeV Higgs. The Higgs searches are still highly constraining, excluding the entire EWBG parameter space at greater than 90% CL except for a small window of m h ≈ 117 − 119 GeV.
The W + W − production cross section measured at the LHC has been consistently exhibiting a mild excess beyond the SM prediction, in both ATLAS and CMS at both 7-TeV and 8-TeV runs. We provide an explanation of the excess in terms of resummation of large logarithms that arise from a jet-veto condition, i.e., the rejection of high-p T jets with p T > p veto T that is imposed in the experimental analyses to reduce backgrounds. Jet veto introduces a second mass scale p veto T to the problem in addition to the invariant mass of the W + W − pair. This gives rise to large logarithms of the ratio of the two scales that need to be resummed. Such resummation may not be properly accounted for by the Monte Carlo simulations used in the ATLAS and CMS studies. Those logarithms are also accompanied by large O(π 2 ) terms when the standard, positive sign is chosen for the squared renormalization scale, µ 2 . We analytically resum the large logarithms including the π 2 terms in the framework of soft collinear effective theory (SCET), and demonstrate that the SCET calculation not only reduces the scale uncertainties of the SM prediction significantly but also renders the theory prediction well compatible with the experiment. We find that resummation of the large logarithms and that of the π 2 terms are both comparably important.
Recent 7 TeV 5/fb measurements by ATLAS and CMS have measured both overall and differential W + W − cross sections that differ from NLO SM predictions. While these measurements aren't statistically significant enough to rule out the SM, we demonstrate that the data from both experiments can be better fit with the inclusion of electroweak gauginos with masses of O(100) GeV. We show that these new states are consistent with other experimental searches/measurements and can have ramifications for Higgs phenomenology. Additionally, we show how the first measurements of the W + W − cross section at 8 TeV by CMS strengthen our conclusions.
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