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].

This document proposes a collection of simplified models relevant to the design of new-physics searches at the Large Hadron Collider (LHC) and the characterization of their results. Both ATLAS and CMS have already presented some results in terms of simplified models, and we encourage them to continue and expand this effort, which supplements both signature-based results and benchmark model interpretations. A simplified model is defined by an effective Lagrangian describing the interactions of a small number of new particles. Simplified models can equally well be described by a small number of masses and cross-sections. These parameters are directly related to collider physics observables, making simplified models a particularly effective framework for evaluating searches and a useful starting point for characterizing positive signals of new physics. This document serves as an official summary of the results from the 'Topologies for Early LHC Searches' workshop, held at SLAC in September

We provide a systematic construction of three-family N = 1 supersymmetric Pati-Salam models from Type IIA orientifolds on T 6 /(Z 2 × Z 2 ) with intersecting D6-branes. All the gauge symmetry factors SU (4) C ×SU (2) L ×SU (2) R arise from the stacks of D6-branes with U (n) gauge symmetries, while the "hidden sector" is specified by U Sp(n) branes, parallel with the orientifold planes or their Z 2 images. The Pati-Salam gauge symmetry can be broken down to the SU (3) C × SU (2) L × U (1) B−L × U (1) I 3R via D6-brane splittings, and further down to the Standard Model via D-and F-flatness preserving Higgs mechanism from massless open string states in a N = 2 subsector. The models also possess at least two confining hidden gauge sectors, where gaugino condensation can in turn trigger supersymmetry breaking and (some) moduli stabilization. The systematic search yields 11 inequivalent models: 8 models with less than 9 Standard model Higgs doublet-pairs and 1 model with only 2 Standard Model Higgs doublet-pairs, 2 models possess at the string scale the gauge coupling unification of SU (2) L and SU (2) R , and all the models possess additional exotic matters. We also make preliminary comments on phenomenological implications of these models.T 6 /(Z 2 × Z 2 ) with intersecting D6-branes where all the gauge symmetries come from U(n) branes. On the one hand, Pati-Salam model provides a natural origin of U(1) B−L and U(1) I 3R both of which are generically required due to the quantum numbers of the SM fermions and the hypercharge interaction in the SM building from intersecting D6-brane scenarios. On the other hand, it also provides one road to the SM without any additional anomaly-free U(1)'s near the electroweak scale, which was a generic feature of the previous supersymmetric SM constructions [28].

We construct an anomaly free supersymmetric U (1) ′ model with a secluded U (1) ′ -breaking sector. We study the one-loop effective potential at finite temperature, and show that there exists a strong enough first order electroweak phase transition for electroweak baryogenesis (EWBG) because of the large trilinear term A h hSH d Hu in the tree-level Higgs potential. Unlike in the MSSM, the lightest stop can be very heavy. We consider the non-local EWBG mechanism in the thin wall regime, and find that within uncertainties the observed baryon number can be generated from the τ lepton contribution, with the secluded sector playing an essential role. The chargino and neutralino contributions and the implications for the Z ′ mass and electric dipole moments are briefly discussed. PACS numbers: 12.60. Jv, 12.60.Cn [ UPR-1063-T ] The baryon asymmetry of the universe has been measured by WMAP [1]. Combining their data with other CMB and large scale structure results, they obtain the ratio of baryon density n B to entropy density sTo generate the baryon asymmetry, the Sakharov criteria [2] must be satisfied: (1) Baryon number (B) violation; (2) C and CP violation; (3) A departure from thermal equilibrium. Electroweak (EW) baryogenesis is especially interesting because the Sakharov criteria can be satisfied in the Standard Model (SM) [3]. However, in the SM the electroweak phase transition (EWPT) cannot be strongly first order for the experimentally allowed Higgs mass, and the CP violation from the CKM matrix is too small. In the Minimal Supersymmetric Standard Model (MSSM), although there are additional sources of CP violation in the supersymmetry breaking parameters, a strong enough first order EWPT requires that the lightest stop quark mass be smaller than the top quark mass ∼ 175 GeV. Also, the mass of the lightest CP even Higgs must be smaller than 120 GeV, which leaves a small window above the current limit [4]. In the Next to Minimal Supersymmetric Standard Model (NMSSM), a trilinear term A h hSH d H u in the tree-level Higgs potential may induce a strong enough first order EWPT [5,6], and the effective µ parameter is given by h S from the Yukawa term hSH d H u in the superpotential in the best-motivated versions. However, most versions either involve a discrete symmetry and serious cosmological domain wall problems [7], or reintroduce the µ problem [6].The possibility of an extra U (1) ′ gauge symmetry is well-motivated in superstring constructions [8]. Similar to the NMSSM, an extra U (1) ′ can provide an elegant solution to the µ problem due to the Yukawa term hSH d H u [9,10]. However, there are no discrete symmetries or domain wall problems. The MSSM upper bound of M Z on the tree-level mass of the lightest MSSM Higgs scalar is relaxed, both in models with a U (1) ′ and in the NMSSM, because of the Yukawa term hSH d H u and the U (1) ′ D-term [11]. Higgs masses lighter than those allowed by LEP in the MSSM are also possible, with the limits relaxed by mixings between Higgs doublets and singlets. There are ...