James A. Maxin

A Higgs mass shift to 125 GeV and a multi-jet supersymmetry signal: Miracle of the flippons at the s=7 TeV LHC

We describe a model named No-Scale F-SU(5) which is simultaneously capable of explaining the dual signals emerging at the LHC of (i) a 124-126 GeV Higgs boson mass m(h), and (ii) tantalizing low-statistics excesses in the multi-jet data which may attributable to supersymmetry. These targets tend to be mutually exclusive in more conventional approaches. The unified mechanism responsible for both effects is the introduction of a rather unique set of vector-like multiplets at the TeV scale, dubbed flippons, which (i) can elevate m(h) by around 3-4 GeV via radiative loop corrections, and (ii) flatten the running of the strong coupling and color-charged gaugino, resulting in a prominent collider signal from production of light gluino pairs. This well-motivated theoretical framework maintains consistency with all key phenomenological constraints, and all residual parameterization freedom may in principle be fixed by a combination of the two experiments described. We project that the already collected luminosity of 5 fb(-1) may be sufficient to definitively establish the status of this model, given appropriate data selection cuts

Ultrahigh jet multiplicity signal of stringy no-scale F-SU(5) at the root s=7 TeV LHC

We present the distinctive collider signatures of no-scale F-SU(5), a highly efficient and phenomenologically favored model built on the tripodal foundations of the F-lipped SU(5) x U(1)(X) grand unified theory, extra F-theory derived TeV scale vectorlike particle multiplets, and the dynamic high-scale boundary conditions of no-scale supergravity. The identifying features of the supersymmetric spectrum are a light stop and gluino, with both sparticles much lighter than all the additional squarks. This unique mass hierarchy leads to the enhanced production of events with an ultrahigh multiplicity of hadronic jets, which should be clearly visible to the root s = 7 TeV LHC at only 1 fb(-1) of integrated luminosity. We suggest a modest alternative event cutting procedure based around a reduced minimal transverse momentum per jet (p(T) > 20 GeV), and an increased minimal multiplicity (>= 9) of distinct jets per subscribed event. These criteria optimize the F-SU(5) signal-to-background ratio, while readily suppressing the contribution of all standard model processes, allowing moreover a clear differentiation from competing models of new physics, most notably minimal supergravity. The characteristic no-scale signature is quite stable across the viable parameter space, modulo an overall rescaling of the mass spectrum; detection by the LHC of the ultrahigh jet signal would constitute a suggestive evocation of the intimately linked stringy origins of F-SU(5) and could possibly provide a glimpse into the underlying structure of the fundamental string moduli.

Dark matter, proton decay and other phenomenological constraints in F-SU(5)

We study gravity mediated supersymmetry breaking in F-SU(5) and its low-energy supersymmetric phenomenology. The gaugino masses are not unified at the traditional grand unification scale, but we nonetheless have the same one-loop gaugino mass relation at the electroweak scale as minimal supergravity (mSUGRA). We introduce parameters testable at the colliders to measure the small second loop deviation from the mSUGRA gaugino mass relation at the electroweak scale. In the minimal SU(5) model with gravity mediated supersymmetry breaking, we show that the deviations from the mSUGRA gaugino mass relations are within 5%. However, in F-SU(5), we predict the deviations from the mSUGRA gaugino mass relations to be larger due to the presence of vector-like particles, which can be tested at the colliders. We determine the viable parameter space that satisfies all the latest experimental constraints and find it is consistent with the CDMS II experiment. Further, we compute the cross-sections of neutralino annihilations into gamma-rays and compare to the first published Fermi-LAT measurement. Finally, the corresponding range of proton lifetime predictions is calculated and found to be within reach of the future Hyper-Kamiokande and DUSEL experiments

The race for supersymmetric dark matter at XENON100 and the LHC: stringy correlations from no-scale F-SU(5)

A bstractThe discovery of supersymmetry (SUSY) via action of the cold dark matter candidate is being led on the indirect collider production front by the LHC, and correspondingly by the XENON100 collaboration on the direct detection front. We undertake a dual case study of the specific SUSY signatures which the No-Scale flipped SU(5) × U(1)X grand unified theory with TeV-scale vector-like particles (No-Scale ℱ-SU(5)) would exhibit at each of these experiments. We demonstrate a correlation between the near-term prospects of these two distinct approaches. We feature a dark matter candidate which is over 99% bino due to a comparatively large Higgs bilinear mass μ term around the electroweak scale, and thus automatically satisfy the current constraints from the XENON100 and CDMS/EDELWEISS experiments. We do however expect that the ongoing extension of the XENON100 run may effectively probe our model. Likewise, our model is also currently being probed by the LHC via a search for events with ultra-high multiplicity hadronic jets, which are a characteristic feature of the distinctive No-Scale ℱ-SU(5) mass hierarchy.

750 GeV diphoton excesses in a realistic D-brane model

We study the diphoton excesses near 750 GeV recently reported by the ATLAS and CMS collaborations within the context of a phenomenologically interesting intersecting/magnetized D-brane model on a toroidal orientifold. It is shown that the model contains a Standard Model singlet scalar as well as vector-like quarks and leptons. In addition, it is shown that the singlet scalar has Yukawa couplings with vector-like quarks and leptons such that it may be produced in proton-proton collisions via gluon fusion as well as decay to diphotons through loops involving the vector-like quarks. Moreover, the required vector-like quarks and leptons may appear in complete SU(5) multiplets so that gauge coupling unification may be maintained. Finally, it is shown that the diphoton signal may be accommodated within the model.

A flippon related singlet at the LHC II

A bstractWe consider the 750 GeV diphoton resonance at the 13 TeV LHC in the ℱ-SU(5) model with a Standard Model (SM) singlet field which couples to TeV-scale vector-like particles, dubbed flippons. This singlet field assumes the role of the 750 GeV resonance, with production via gluon fusion and subsequent decay to a diphoton via the vector-like particle loops. We present a numerical analysis showing that the observed 8 TeV and 13 TeV diphoton production cross-sections can be generated in the model space with realistic electric charges and Yukawa couplings for light vector-like masses. We further discuss the experimental viability of light vector-like masses in a General No-Scale ℱ-SU(5) model, offering a few benchmark scenarios in this consistent GUT that can satisfy all experimental constraints imposed by the LHC and other essential experiments.

A Two-Tiered Correlation of Dark Matter with Missing Transverse Energy: Reconstructing the Lightest Supersymmetric Particle Mass at the LHC

A bstractWe suggest that non-trivial correlations between the dark matter particle mass and collider based probes of missing transverse energy

Correlating LHCb Bs0 → μ+μ− results with the ATLAS-CMS multijet supersymmetry search

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Confronting Electroweak Fine-tuning with No-Scale Supergravity

may facilitate a two tiered approach to the initial discovery of supersymmetry and the subsequent reconstruction of the lightest supersymmetric particle (LSP) mass at the LHC. These correlations are demonstrated via extensive Monte Carlo simulation of seventeen benchmark models, each sampled at five distinct LHC center-of-mass beam energies, spanning the parameter space of No-Scale

THE F-LANDSCAPE: DYNAMICALLY DETERMINING THE MULTIVERSE

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