3,034 research outputs found
An interesting NMSSM scenario at the LHC and LC
No full textThe Next-to-Minimal Supersymmetric Standard Model NMSSM provides an attractive extension to the minimal supersymmetric model by including an extra Higgs singlet superfield. This extension allows one to link the Higgs-higgsino mass parameter to a vacuum expectation value of the new scalar field, thus providing a solution to the mu-problem of the MSSM. It this report, presented within the context of the LHC / LC Study Group, we examine a particularly interesting NMSSM scenario where the extra Higgs scalar is rather light. We determine LHC production cross-sections and branching ratios for the lightest scalar and find that it will be difficult to observe at the LHC. However, we show that this lightest scalar can instead be observed at an electron-positron Linear Collider for all but a small window of parameter space. <br/
Constrained exceptional supersymmetric standard model with a Higgs signal near 125GeV
No full textWe study the parameter space of the constrained exceptional supersymmetric standard model (cE⁶SSM) consistent with a Higgs signal near 125 GeV and the LHC searches for squarks, gluinos and Z′. The cE⁶SSM parameter space, consistent with correct electroweak symmetry breaking, is represented by scans in the (m₀,M₁/₂) plane for fixed Z′ mass and tanβ, with squark, gluino and Higgs masses plotted as contours in this plane. We find that a 125 GeV Higgs mass only arises for a sufficiently large Z′ mass, mostly above current limits, and for particular regions of squark and gluino masses corresponding to multi-TeV squark masses, but with lighter gluinos typically within reach of the LHC 8 TeV or forthcoming 14 TeV runs. Successful dark matter relic abundance may be achieved over all the parameter space, assuming a binolike lightest supersymmetric particle with a nearby heavier inert Higgsino doublet and decoupled inert singlinos, resulting in conventional gluino decay signatures. A set of typical benchmark points with a Higgs near 125 GeV is provided which exemplifies these features.P. Athron, S. F. King, D. J. Miller, S. Moretti, and R. Nevzoro
Higgs bosons in the NMSSM with exact and slightly broken PQ-symmetry
No full textWe explore the Higgs sector of the NMSSM in the limit when the Peccei--Quinn symmetry is exact or only slightly broken. In this case the Higgs spectrum has a hierarchical structure which is caused by the stability of the physical vacuum. We find a strong correlation between the parameters of the NMSSM if \kappa=0 or \kappa\lesssim \lambda^2. It allows one to distinguish the NMSSM with exact or softly broken PQ-symmetry from the MSSM even when extra scalar and pseudoscalar Higgs states escape direct detection. <br/
Predictions of the constrained exceptional supersymmetric standard model
No full textWe discuss the predictions of a constrained version of the exceptional supersymmetric standard model (cE6SSM), based on a universal high energy soft scalar mass m0, soft trilinear coupling A0 and soft gaugino mass M1/2. We predict a supersymmetry (SUSY) spectrum containing a light gluino, a light wino-like neutralino and chargino pair and a light bino-like neutralino, with other sparticle masses except the lighter stop being much heavier. In addition, the cE6SSM allows the possibility of light exotic colour triplet charge 1/3 fermions and scalars, leading to early exotic physics signals at the LHC. We focus on the possibility of a Z? gauge boson with mass close to 1 TeV, and low values of (m0,M1/2), which would correspond to an LHC discovery using “first data”, and propose a set of benchmark points to illustrate this.<br/
Phenomenological consequences of the constrained exceptional supersymmetric standard model
No full textThe Exceptional Supersymmetric Standard Model (E6SSM) provides a low energy alternative to the MSSM, with an extra gauged U(1)N symmetry, solving the ??problem of the MSSM. Inspired by the possible embedding into an E6 GUT, the matter content fills three generations of E6 multiplets, thus predicting exciting exotic matter such as diquarks or leptoquarks. We present predictions from a constrained version of the model (cE6SSM), with a universal scalar mass m0, trilinear mass A and gaugino mass M1/2. We reveal a large volume of the cE6SSM parameter space where the correct breakdown of the gauge symmetry is achieved and all experimental constraints satisfied. We predict a hierarchical particle spectrum with heavy scalars and light gauginos, while the new exotic matter can be light or heavy depending on parameters. We present representative cE6SSM scenarios, demonstrating that there could be light exotic particles, like leptoquarks and a U(1)N Z’ boson, with spectacular signals at the LHC.<br/
Single charged Higgs boson production at next generation linear colliders
No full textWe study the single production of charged Higgs bosons in e+e- collisions, chiefly in the Minimal Supersymmetric Standard Model. Our analysis complements foregoing studies of the pair production channel especially in regions where the kinematic constraint suppresses pair production. We present cross sections relevant to experiments at the next generation linear colliders and some brief discussions of their phenomenology. Our analysis shows that the single production is a useful alternative channel for studying the phenomenology of charged Higgs bosons, and there are regions of parameter space where it is accessible beyond the kinematic limit for pair production
Electroweak symmetry breaking in the E6SSM
No full textThe Exceptional Supersymmetric Standard Model (E6SSM) is an E6 inspired model with an extra gauged U(1) symmetry, which solves the ?-problem in a similar way to the NMSSM but without the accompanying problems of singlet tadpoles or domain walls. It predicts new exotic particles at the TeV scale. We investigate the Renormalisation Group Evolution of the model and test electroweak symmetry breaking for a selection of interesting scenarios with non-universal Higgs masses at the GUT scale. We present a detailed particle spectrum that could be observed at the LHC
Rapporteur’s report – innovative geotechnologies for energy transition
No full textThe 9th Society for Underwater Technology (SUT) International Conference on Offshore Site Investigation and Geotechnics (OSIG) closed with a Rapporteur’s report given by the author. This paper provides a record of that report, transcribed from a video recording. The presentation slides are shown as Figures.</p
Collider phenomenology of the E6SSM
No full textWe consider collider signatures of the exceptional supersymmetric (SUSY) standard model (E6SSM). This E6 inspired SUSY model is based on the SM gauge group together with an extra U(1) gauge symmetry under which right--handed neutrinos have zero charge. To ensure anomaly cancellation and gauge coupling unification the low energy matter content of the E6SSM involve extra exotic matter beyond the MSSM. We discuss the collider signatures associated with the production of new particles predicted by the E6SSM and consider the implications of this model for dark matter and Higgs phenomenology. Since exotic quarks in the E6SSM can be either diquarks or leptoquarks they may provide spectacular new physics signals at the LH
DEFRApH - Sample collection and handling procedures
No full textAll chemical and biogeochemical process in the sea are affected by the acidity of the water. Acidity is therefore fundamental property of seawater. The growing concern that the acidity of the oceans might be increasing has revealed weaknesses in our knowledge of this fundamental property and its variation in space and time. In 2008 the DEFRApH project (DEFRA contract ME4133) was initiated to provide this missing information in UK related waters. It required sampling for and analysis of the total inorganic carbon and total alkalinity content of samples. This reports documents the procedures sued for sampling. A companion document Hartman Dumousseaud and Roberts (NOC Internal Document No. 01) describes in detail the analytical procedures used and the calculation of the results
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