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arXiv2024

Assisted baryon number violation from $4k+2$ dimensions

Proton decay in six dimensions orbifolded on square $T^2/Z_2$ is highly suppressed at tree-level. This is because baryon number violating (BNV) operators containing only the zero mode of bulk fermions must satisfy the selection rule $\frac{3}{2} ΔB \pm \frac{1}{2}ΔL = 0 \ mod \ 4$. In this article, we show that the above relation does not prohibit mass dimension-6 BNV operators containing Kaluza Klein (KK) partners of the bulk fermions. Together with `spinless' adjoint scalar partner of hypercharge gauge boson (the Dark Matter candidate), these novel operators generate Dark Matter assisted proton decay at mass dimension-8. Here, with explicit examples of scalar and vector baryon number violating interactions, we discuss the importance of such $ΔB=1 =ΔL$ and $ΔB=2=ΔL$ operators and derive the limit on New Physics.

hep-ph↗

arXiv2022

Flavour violating charged lepton decays in Little Randall-Sundrum Model

The Little Randall-Sundrum (Little RS) model receives significantly stronger constraints from the flavour observables in comparison to Randall-Sundrum (RS) model. In this paper, we analyse the effect of the electro-weak sector in Little RS on flavour changing decays of charged leptons. We compare the predictions of the model with the current limits on the flavour violating Branching Ratios of $μ\rightarrow e e e $, $τ\rightarrow e e e $, $τ\rightarrow μμμ$, $τ\rightarrow μe e $, $τ\rightarrow e μμ$ , $μ\rightarrow e γ$, and $μTi \rightarrow e Ti $. And we show that the dominant constraint arises from the $μTi \rightarrow e Ti$ process which strongly limits the KK-1 gauge boson mass ($M_{KK}$) to be $\gtrsim 30.7 TeV $. We then derive and show that generalising the electro-weak gauge sector to include the Brane Localised Kinetic Term (BLKT) relaxes this constraint to $\gtrsim 12 TeV$. Towards the conclusion, we comment on the possibility that the large flavour violating currents can be mitigated by relaxing the assumption regarding the unnatural thinness and rigidity of the UV-brane and discuss the possibility of suppression of these currents in presence of fat fluctuating branes.

hep-ph↗