arXiv subjects

Roberto Franceschini

Publications and source records attributed to Roberto Franceschini.

57 records · Page 4Linked to original sources

arXiv2007

Supersymmetry without a light Higgs boson at the LHC

We analyze the LHC phenomenology of lambdaSUSY - a version of NMSSM with a largish SH1H2 coupling. The scalar spectrum of the model contains a 200-300 GeV Higgs boson h with Standard-Model like properties, and heavy CP-even and CP-odd Higgs bosons H and A with masses in 500-800 GeV range. We study the discovery potential of H and A in the decay chains H->hh->4V->2l6j and A->Zh->Z2V->2l4j. The dominant backgrounds are the diffuse Z6j and Z4j productions, which can be suppressed by demanding reconstruction of V's and h's in intermediate states. The excess of signal events allows for a discovery of both H and A with over 5sigma significance for 100 inverse fb of integrated luminosity.

hep-ph↗

arXiv2007

Supersymmetric LHC phenomenology without a light Higgs boson

After a brief discussion of the mass of the Higgs in supersymmetry, I introduce \lambdaSUSY, a model with an extra chiral singlet superfield in addition to the MSSM field content. The key features of the model are: the superpotential W=λS H_d H_u with a large coupling λand the resulting lightest Higgs with mass above 200GeV. The main part of my contribution will be about how \lambdaSUSY manifests itself at the LHC. Discoveries of gluino, squarks and in particular of the three lightest neutral Higgs bosons are discussed.

hep-ph↗

arXiv2006

Neutrino Masses with Inverse Hierarchy from Broken L_e-L_μ-L_τ: a Reappraisal

We discuss a class of models of neutrino masses and mixings with inverse hierarchy based on a broken U(1)_F flavour symmetry with charge L_e-L_μ-L_τfor lepton doublets and arbitrary right-handed charges. The symmetry breaking sector receives separate contributions from flavon vev breaking terms and from soft mass breaking in the right handed Majorana sector. The model is able to reproduce in a natural way all observed features of the charged lepton mass spectrum and of neutrino masses and mixings (even with arbitrarily small θ_{13}), with the exception of a moderate fine tuning which is needed to accomodate the observed small value of r = Delta m^2_{sol} / Delta m^2_{atm}.

hep-ph↗