Eduard Masso

Higgs windows to new physics through d = 6 operators: constraints and one-loop anomalous dimensions

A bstractThe leading contributions from heavy new physics to Higgs processes can be captured in a model-independent way by dimension-six operators in an effective Lagrangian approach. We present a complete analysis of how these contributions affect Higgs couplings. Under certain well-motivated assumptions, we find that 8 CP-even plus 3 CP-odd Wilson coefficients parametrize the main impact in Higgs physics, as all other coefficients are constrained by non-Higgs SM measurements. We calculate the most relevant anomalous dimensions for these Wilson coefficients, which describe operator mixing from the heavy scale down to the electroweak scale. This allows us to find the leading-log corrections to the predictions for the Higgs couplings in specific models, such as the MSSM or composite Higgs, which we find to be significant in certain cases.

Renormalization of dimension-six operators relevant for the Higgs decays h → γγ, γZ

A bstractThe discovery of the Higgs boson has opened a new window to test the SM through the measurements of its couplings. Of particular interest is the measured Higgs coupling to photons which arises in the SM at the one-loop level, and can then be significantly affected by new physics. We calculate the one-loop renormalization of the dimension- six operators relevant for h → γγ, γZ, which can be potentially important since it could, in principle, give log-enhanced contributions from operator mixing. We find however that there is no mixing from any current-current operator that could lead to this log-enhanced effect. We show how the right choice of operator basis can make this calculation simple. We then conclude that h → γγ, γZ can only be affected by RG mixing from operators whose Wilson coefficients are expected to be of one-loop size, among them fermion dipole-moment operators which we have also included.

Light spinless particle coupled to photons.

A pseudoscalar or scalar particle

Compatibility of Cast Search with Axionlike Interpretation of PVLAS Results

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Gamma Rays from SN 1987A due to Pseudoscalar Conversion

that couples to two photons but not to leptons, quarks and nucleons would have effects in most of the experiments searching for axions, since these are based on the

Need for purely laboratory-based axionlike particle searches

a \gamma \gamma

Evading astrophysical constraints on axion-like particles

coupling. We examine the laboratory, astrophysical and cosmological constraints on

Axion thermalization in the early universe

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Dipolar dark matter

and study whether it may constitute a substantial part of the dark matter. We also generalize the

An Effective Guide to Beyond the Standard Model Physics

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