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Combined explanations of B-physics anomalies: the sterile neutrino solution

Abstract In this paper we provide a combined explanation of charged- and neutral-current B-physics anomalies assuming the presence of a light sterile neutrino NR which contributes to the B → D(*)τν processes. We focus in particular on two simplified models, where the mediator of the flavour anomalies is either a vector leptoquark U 1 μ ∼ (3, 1, 2/3) or a scalar leptoquark S1...

Note on gauge and gravitational anomalies of discrete Z N symmetries

In this note, we discuss the consistency conditions which a discrete Z N symmetry should satisfy in order that it is not violated by gauge and gravitational instantons. As examples, we enlist all the Z N ℛ-symmetries as well as non-ℛ Z N symmetries (N=2,3,4) in the minimally supersymmetric standard model (MSSM) that are free from gauge and gravitational anomalies. We show that...

A closer look at the R D and R D* anomalies

The measurement of R D (R D*), the ratio of the branching fraction of \( \overline{B}\to D\tau {\overline{\nu}}_{\tau}\left(\overline{B}\to {D}^{\ast}\tau {\overline{\nu}}_{\tau}\right) \) to that of \( \overline{B}\to Dl{\overline{\nu}}_l\left(\overline{B}\to {D}^{\ast }l{\overline{\nu}}_l\right) \), shows 1.9σ (3.3σ) deviation from its Standard Model (SM) prediction. The...

The 750 GeV diphoton resonance as an sgoldstino: a reappraisal

Among the various explanations of the possible 750 GeV diphoton resonance, the possibility of it being an sgoldstino is an attractive one, as it is related to the spontaneous breaking of global supersymmetry. We discuss this possibility in this paper and point out the various theoretical issues associated with it. In particular, we indicate the difficulties of this explanation in...

CP violation tests of alignment models at LHCII

We analyse the low-energy phenomenology of alignment models both model-independently and within supersymmetric (SUSY) scenarios focusing on their CP violation tests at LHCII. Assuming that New Physics (NP) contributes to \( {K}^0-{\overline{K}}^0 \) and \( {D}^0-{\overline{D}}^0 \) mixings only through non-renormalizable operators involving SU(2) L quark-doublets, we derive model...

Light stop in the MSSM after LHC Run 1

The discovery of a Higgs boson with a mass of 126 GeV at the LHC when combined with the non-observation of new physics both in direct and indirect searches imposes strong constraints on supersymmetric models and in particular on the top squark sector. The experiments for direct detection of dark matter have provided with yet more constraints on the neutralino LSP mass and its...

Hint of lepton flavour non-universality in B meson decays

The LHCb collaboration has recently presented their result on R K = ℬ(B + → K + μ + μ −)/ ℬ(B + → K + e + e −) for the dilepton invariant mass bin m ℓℓ 2 = 1 − 6 GeV2 (ℓ = μ, e). The measurement shows an intriguing 2.6σ deviation from the Standard Model (SM) prediction. In view of this, we study model independent New Physics (NP) explanations of R K consistent with other...

Same sign di-lepton candles of the composite gluons

Composite Higgs models, where the Higgs boson is identified with the pseudo-Nambu-Goldstone-Boson (pNGB) of a strong sector, typically have light composite fermions (top partners) to account for a light Higgs. This type of models, generically also predicts the existence of heavy vector fields (composite gluons) which appear as an octet of QCD. These composite gluons become very...

Multi-leptons and top-jets in the hunt for gluinos in R-parity violating supersymmetry

The presence of R-parity \( \left( {{{\mathcal{R}}_p}} \right) \) violation offers intersting decay channels for the gluinos. In this work we present a new search strategy for the gluinos in the presence of semileptonic \( {{\mathcal{R}}_p} \) violating couplings \( \lambda_{133}^{\prime } \) and \( \lambda_{233}^{\prime } \) . We consider two scenarios (i) λ′ induced 3-body...

Exploring new physics in the C 7-C 7′ plane

The Wilson coefficient C 7 governing the radiative electromagnetic decays of B meson has been calculated toa very high accuracy in the Standard Model, but experimental bounds on either the magnitude or the sign of C 7 are often model-dependent. In the present paper, we attempt at constraining both the magnitude and sign of C 7 using a systematic approach. We consider already...