Higgs and supersymmetry

“…No-scale models have the additional attractive feature that they arise in generic four-dimensional reductions of string theory [10], though this does not play an essential role in our analysis. The attractive features of this no-scale supergravity framework for inflation do not depend sensitively on the supersymmetry-breaking scale, which could be anywhere between the experimental lower limit $1 TeV from the LHC [11] and $10 10 TeV from the tensor-to-scalar ratio.…”

mentioning

confidence: 99%

Publisher’s Note: No-Scale Supergravity Realization of the Starobinsky Model of Inflation [Phys. Rev. Lett.111, 111301 (2013)]

Ellis¹,

Nanopoulos²,

Olive³

2013

Phys. Rev. Lett.

144

233

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We present a model for cosmological inflation based on a no-scale supergravity sector with an SUð2; 1Þ=SUð2Þ Â Uð1Þ Kähler potential, a single modulus T, and an inflaton superfield È described by a Wess-Zumino model with superpotential parameters (, ). When T is fixed, this model yields a scalar spectral index n s and a tensor-to-scalar ratio r that are compatible with the Planck measurements for values of ' =3M P . For the specific choice ¼ =3M P , the model is a no-scale supergravity realization of the R þ R 2 Starobinsky model. The initial release of cosmic microwave background data from the Planck satellite [1] confronts theorists of cosmological inflation [2,3] with a challenge. On the one hand, the data have many important features that are predicted qualitatively by the inflationary paradigm. For example, there are no significant signs of non-Gaussian fluctuations or hints of nontrivial topological features such as cosmic strings, and the spectrum of scalar density perturbations exhibits a significant tilt: n s '0:960AE0:007, as would be expected if the effective scalar energy density decreased gradually during inflation. On the other hand, many previously popular field-theoretical models of inflation are ruled out by a combination of the constraint on n s and the tensor-to-scalar ratio r < 0:08 as now imposed by Planck et al: see, e.g., Fig. 1 [5] and related models [6].In the following paragraphs we motivate the approach to inflation taken in this Letter, which casts a new light on the Starobinsky model [4] and embeds it in a more general theoretical context that connects with other ideas in particle physics. Specifically, the upper limit on r implies that the energy scale during inflation must be much smaller than the Planck energy, $10 19 GeV. Such a hierarchy of energy scales can be maintained naturally, without fine-tuning, in a theory with supersymmetry [7]. As is well known, (approximate) supersymmetry has many attractive features, such as providing a natural candidate for dark matter and facilitating grand unification, as well as alleviating the fine-tuning of the electroweak scale. In the context of early-universe cosmology, one must combine supersymmetry with gravity via a suitable supergravity theory [8], which should accommodate an effective inflationary potential that varies slowly over a large range of inflaton field values. This occurs naturally in a particular class of supergravity models [9], which are called ''no scale'' because the scale at which supersymmetry is broken is undetermined in a first approximation, and the energy scale of the effective potential can be naturally much smaller than $1019 GeV, as required by the cosmic microwave background data. No-scale models have the additional attractive feature that they arise in generic four-dimensional reductions of string theory [10], though this does not play an essential role in our analysis. The attractive features of this no-scale supergravity framework for inflation do not depend sensitively on the supersymmetry-breaking scale, w...

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“…There are several regions of the CMSSM parameter space that are compatible with the constraints imposed by unsuccessful searches for sparticles at the LHC, as well as the discovered Higgs boson mass and the LSP relic density allowed by cosmological observations. It was found in a global analysis that these two possibilities are favoured [41]: (a) a region where the relic density is controlled by rapid annihilation through direct-channel heavy Higgs resonances due to the relatively large higgsino component of the LSP, and (b) a strip where the relic LSP density is reduced by coannihilations with near-degenerate staus and other sleptons.…”

Section: Metastable Lepton Nlsp In the Cmssm With A Neutralino Lspmentioning

confidence: 99%

Searches for magnetic monopoles and beyond with MoEDAL at the LHC

Mitsou

2018

EPJ Web of Conferences

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Abstract.The MoEDAL experiment at the LHC is optimised to detect highly-ionising particles such as magnetic monopoles, dyons and (multiply) electrically-charged stable massive particles predicted in a number of theoretical scenarios. MoEDAL, deployed in the LHCb cavern, combines passive nuclear track detectors with magnetic monopole trapping volumes, while cavern backgrounds are being monitored with an array of MediPix detectors. The detector concept and its physics reach is presented with emphasis given to recent results on monopole searches providing the best limits on high magnetic charges in colliders. The potential to search for heavy, long-lived supersymmetric electrically-charged particles and multi-charged states is also discussed.

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Higgs and supersymmetry

Cited by 181 publications

References 95 publications

Indirect and direct detection prospect for TeV dark matter in the nine parameter MSSM

Indirect and direct detection prospect for TeV dark matter in the nine parameter MSSM

Publisher’s Note: No-Scale Supergravity Realization of the Starobinsky Model of Inflation [Phys. Rev. Lett.111, 111301 (2013)]

Searches for magnetic monopoles and beyond with MoEDAL at the LHC

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