119632193
Unravelling the sbottom spin at the CERN LHC
Establishing that a signal of new physics is undoubtedly supersymmetric requires not only the discovery of the supersymmetric partners but also probing their spins and couplings. We show that the sbottom spin can be probed at the CERN Large Hadron Collider using only angular correlations in the reaction pp{yields}b-tildeb-tilde*{yields}bbpe{sub T}, which allow us to distinguish a universal extra dimensional interpretation with a fermionic heavy bottom quark from supersymmetry with a bosonic bottom squark. We demonstrate that this channel provides a clear indication of the sbottom spin provided the sbottom production rate and branching ratio into b{chi}-tilde{sub 1}{sup 0} are sufficiently large to have a clear signal above standard model backgrounds.
119240724
Observing Higgs dark matter at the CERN LHC
Triggering the electroweak symmetry breaking may not be the only key role played by the Higgs boson in particle physics. In a recently proposed warped five-dimensional SO(5) ⊗ U(1) gauge-Higgs unification model, the Higgs boson can also constitute the dark matter that permeates the universe. The stability of the Higgs boson in this model is guaranteed in all orders of perturbation theory by the conservation of an H-parity quantum number that forbids triple couplings to all standard model (SM) particles. Such a unique feature of the model shows up as a delay in the restoration of the tree-level unitarity, which in turn enhances the production cross section as compared to the standard model analogue. Recent astrophysical data constrain the mass of such a Higgs dark matter particle to a narrow window of 70-90 GeV range. We show that the Large Hadron Collider can observe these Higgs bosons in the weak boson fusion channel with about 260 fb -1 of integrated luminosity in that mass range.
56111830
Is There a Hidden Principle in the Higgs Boson Decay to Photons
It is remarkable that the measured Higgs boson mass is so close to the value which maximizes the Higgs decay rate to photons as predicted by the Standard Model. In this letter we explore the consequences to assume that an ∼ 126 GeV Higgs boson mass is not accidental, but fixed by some fundamental principle that enforces it to maximize its decay rate into photons. We provide evidence that only a very narrow slice of the parameters space of the Standard Model, which contains their measured values, could lead to a maximal Higgs boson with that mass. If the principle actually holds, several Standard Model features get fixed, as the number of fermion families, quark colors, and the CP nature of the new boson, for example. We also ilustrate how such principle can place strong bounds on new physics scenarios as a Higgs dark portal model, for example.
118570640
Is the new resonance spin 0 or 2? Taking a step forward in the Higgs boson discovery
The observation of a new boson of mass $\sim 125\gev$ at the CERN LHC may finally have revealed the existence of a Higgs boson. Now we have the opportunity to scrutinize its properties, determining its quantum numbers and couplings to the standard model particles, in order to confirm or not its discovery. We show that by the end of the 8 TeV run, combining the entire data sets of ATLAS and CMS, it will be possible to discriminate between the following discovery alternatives: a scalar $J^P=0^+$ or a tensor $J^P=2^+$ particle with minimal couplings to photons, at a $5\sigma$ statistical confidence level at least, using only diphotons events. Our results are based on the calculation of a center-edge asymmetry measure of the reconstructed {\it sPlot} scattering polar angle of the diphotons. The results based on asymmetries are shown to be rather robust against systematic uncertainties with comparable discrimination power to a log likelihood ratio statistic.
119907543
Hadron spectroscopy and exotic states
This contribution summarizes some of the main results from the LHC experiments on hadron spectroscopy and exotic states.
126244363
Heavy flavor physics in LHCb