arXiv subjects

Jhovanny Mejia-Guisao

Publications and source records attributed to Jhovanny Mejia-Guisao.

3 recordsLinked to original sources

arXiv2020

Experimental status of CPV in $B_s^0$ mixing

This proceeding contribution presents the latest measurement of the CP-violation and other physics parameters in the $B_s^0 \to J/ψϕ$ decay channel performed by the ATLAS, CMS and LHCb experiments. The measurements are based on a data set collected at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV. Besides the CP violating phase $ϕ_s$, the width difference between the $B_{s}^0$ meson mass eigenstates $ΔΓ_s$ and the average decay width $Γ_s$ are measured. The measured values are then combined with those collected at 8 TeV. The measurements are consistent with theoretical predictions based on the Standard Model.

hep-ex↗

arXiv2018

Lepton number violation in $B_s$ meson decays induced by an on-shell Majorana neutrino

Lepton-number violation can be induced by the exchange of an on-shell Majorana neutrino $N$ in semileptonic $|ΔL|=2$ decays of the $B_s$ meson, $B_s^0 \to P^-π^-μ^+ μ^+$ with $P=K, D_s$. We investigate the production of such a heavy sterile neutrino through these four-body $μ^+μ^+$ channels and explore the sensitivity that can be reached at the LHCb and CMS experiments. For heavy neutrino lifetimes of $τ_N$ = [1, 100, 1000] ps and integrated luminosities collected of 10 and 50 fb${}^{-1}$ at the LHCb and 30, 300, and 3000 fb${}^{-1}$ at the CMS, we find a significant sensitivity on branching fractions of the orders ${\rm BR}(B_s^0 \to K^- π^-μ^+ μ^+) \lesssim \mathcal{O}(10^{-9} - 10^{-8})$ and ${\rm BR}(B_s^0 \to D_s^- π^-μ^+ μ^+) \lesssim \mathcal{O}(10^{-8} - 10^{-7})$. In the kinematically allowed mass ranges of $m_N \in [0.25,4.77]$ GeV and $m_N \in [0.25,3.29]$ GeV, respectively, we exclude regions on the parameter space ($m_N,|V_{μN}|^{2}$) associated with the heavy neutrino, which could slightly improve the limits from $B^- \to π^+μ^-μ^-$ (LHCb).

hep-ph↗

arXiv2017

Exploring GeV-scale Majorana neutrinos in lepton-number-violating $Λ_b^0$ baryon decays

In this work, the lepton-number-violating processes in $|ΔL|=2$ decays of $Λ_b^0$ baryon, $Λ_b^0 \to p π^+μ^- μ^-$ and $Λ_b^0 \to Λ_c^+ π^+μ^- μ^-$, are investigated for the first time, via an intermediate on-shell Majorana neutrino $N$ with a mass in the GeV scale. We explore the experimental sensitivity of these dimuon channels at the LHCb and CMS experiments, in which heavy neutrino lifetimes in the accessible ranges of $τ_N = [1, 100, 1000]$ ps are considered. For a integrated luminosity collected of 10 and 50 fb${}^{-1}$ at the LHCb and 30, 300 and 3000 fb${}^{-1}$ at the CMS, we found significant sensitivity on branching fractions of the order ${\rm BR}(Λ_b^0 \to p π^+μ^- μ^-) \lesssim \mathcal{O}(10^{-9} - 10^{-8})$ and ${\rm BR}(Λ_b^0 \to Λ_c^+ π^+μ^- μ^-) \lesssim \mathcal{O}(10^{-8} - 10^{-7})$. Exclusion regions on the parameter space ($m_N,|V_{μN}|^{2}$) associated with the heavy neutrino are presented and compared with those from $K^- \to π^+μ^-μ^-$ (NA48/2) and $B^- \to π^+μ^-μ^-$ (LHCb) as well as by different search strategies such as NA3, CHARMII, NuTeV, Belle, and DELPHI.

hep-ph↗