Next to Minimal Higgs : Mass Bounds and Search Prospects

The Standard Model of electroweak interactions has one scalar doublet. The minimal extension of this sector is effected by adding a neutral, singlet scalar field. Depending on whether the singlet field has a non-zero vacuum expectation value, x, or not, the scenario has quite distinctive predictions. In particular, x unequal to 0 produces a mixing between the usual SU(2) doublet and the singlet, giving rise to two physical states and a goldstone boson with non-vanishing coupling to these. Presence of this coupling modifies the 2 jets + missing energy signal of the Bjorken process at LEP. We update the bounds on the Higgs mass using the LEP-1 data. We then explore, using parton-level Monte Carlo event generators, the production of these scalars at the LHC via gluon-gluon fusion and subsequent detection. We compare the signals with the expected backgrounds.Comment: 16 pages and 7 Postscript figures, Late

The Relationship Between the Markup and Inflation in the G7 Plus One Economies

Digitised version produced by the EUI Library and made available online in 2020

A note on gauge-fixing in the electroweak sector of nmUED

Electroweak observables are highly sensitive to the loop corrections. Therefore, a proper gauge-fixing mechanism is always needed to define the propagators which are involved in Feynman loop amplitude. With this spirit we compute gauge-fixing mechanism in five dimensional (5-D) Universal Extra-Dimensional (UED) model with boundary localised terms (BLTs). These BLTs are not 5-D operators in four-dimensional (4-D) effective theory but some sort of boundary conditions on the respective fields at the fixed points of $S^1/Z_2$ orbifold. Furthermore, these BLTs non-trivially modify the Kaluza-Klein (KK) spectra and some of the interactions among the KK-excitations compared to the minimal UED (mUED), in which, these BLTs are absent. In this note we calculate the gauge-fixing mechanism in the electroweak sector of such non-trivial UED scenario. Moreover, we discuss the composition and masses of Goldstone and any physical scalar that emerge after the symmetry breaking in this set up with different choices of gauge.Comment: 9 pages, title has been changed, matched with the published versio