Exploring non minimal Universal Extra Dimensional model at the LHC

Abstract

We study the collider phenomenology of non minimal universal extra dimensional (nmUED) model in the context of the Large Hadron Collider at CERN. nmUED is an incarnation of the Standard Model in (4 + 1) space-time dimensions compactified on an S 1 /Z 2 orbifold supplemented with boundary localized operators with unknown coefficients. These coefficients parametrize the radiative corrections which are somehow arbitrary due to the lack of knowledge of the cut-off scale of such effective theory. It is possible to tune the masses and couplings of the Kaluza Klein (KK) excitations by tuning these parameters. Two scenarios with different mass hierarchies among the KK-excitations have been considered. A detailed study of production cross-sections and different decay modes of KK-particles are also presented. We calculate the correlated bounds on masses of KK-particles using the LHC nl + mj + E / T data (in case of production of strongly interacting particles) and 3l + E / T data (in case of electroweak productions). We work in a KK-parity conserving scenario where the lightest KK-particle is a potential dark (DM) matter candidate. We use the additional constraints coming from the observed DM relic density of the universe to identify the allowed parameter space. The current status of a nmUED model in the light of DM direct detection data is also examined. The present investigation reveals that production and subsequent leptonic decays of KK-electroweak gauge bosons as massive as 1 TeV, lead to observable trilepton signature with a luminosity of 1 ab −1 which will be realized in near future.1 It has been shown that one loop effects in a theory with one extra space-like dimension are only log sensitive to the cut-off [28].2 The cut-off dependence of different physical observables is studied in [30].

Inflationary limits on the size of compact extra space

“…It will be shown in this Section that the process of inflation described above cannot be realized if the size of compact extra space l d is larger than the horizon size. More definitely, we show that if H const (8) and…”

“…Both of them varies in range from the Planck scale to the scale ∼ 1TeV for m D and to ∼ 10 −18 cm for l d depending on a specific model. The hope to find them at the LHC collider is based on these numbers, see [7,8]. At the same time, there exists another collider created by Nature itself -the early Universe, or more definitely its first stage of evolution -the inflation.…”

Looking for B→Xsℓ+ℓ− in a nonminimal universal extra dimensional model

“…In literature one can find different such exercise regarding various phenomenological aspects. As for example limits on the values of the strengths of the BLTs have been achieved from the estimation of electroweak observables [43,45], S, T and U parameters [41,46], DM relic density [47,48], production as well as decay of SM Higgs boson [49], collider study of LHC experiments [50][51][52][53][54][55], R b [56], branching ratios of some rare decay processes e.g., B s → µ + µ − [7] and B → X s γ [8], R D ( * ) anomalies [9,57], flavour changing rare top decay [58,59] and unitarity of scattering amplitudes involving KK-excitations [60].…”

The impact of nonminimal universal extra dimensional model on $$\Delta B=2$$ transitions

“…In this section we overview the salient features of the nmUED scenario necessary for our current analysis. One can find detailed description of this scenario in [33][34][35][36][37][38][39][40][46][47][48][49][50][51][52][53][54][55][56]. In order to conserve the KK-parity, coefficients of boundary terms at both the boundary points (y = 0 and y = π R) are kept equal.…”

“…In literature there exists number of phenomenological studies in this scenario. For example, bounds on the values of the coefficients of the BLTs have been obtained from the evaluation of electroweak observables [39,41], S, T and U parameters [37,42], DM relic density [43,44], production as well as decay of SM Higgs boson [45], collider study of LHC experiments [46][47][48][49][50][51], Z → bb [52], branching ratios of some rare decay processes of B-meson: e.g., B s → μ + μ − [53], B → X s γ [54] and B → X s + − [55], R D ( * ) anomalies [56][57][58], flavour changing rare top decay [59,60] and unitarity of scattering amplitudes containing KK-excitations [61].…”