arXiv subjects

Diego Milanes

Publications and source records attributed to Diego Milanes.

5 recordsLinked to original sources

arXiv2018

Search for lepton-number-violating signals in the charm sector

We explore signals of lepton-number-violation in the charm physics sector. We study the four-body $|ΔL|= 2$ decays of the $D^0$ meson, $D^0 \to P^- π^-μ^+ μ^+$ ($P = π, K$) as an alternative evidence of the Majorana nature of neutrinos. We carry out an exploratory study on the potential sensitivity that LHCb experiment could achieve for these $|ΔL|= 2$ processes. We show that for a long term expected integrated luminosity of 300 fb$^{-1}$, a signal significance of branching ratios of the order $\mathcal{O}(10^{-9})$ might be accessible, allowing to improve the experimental bounds obtained by the E791 experiment. Limits on the parameter space of a heavy sterile neutrino that could be obtained from their experimental search are discussed as well.

hep-ph↗

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↗

arXiv2016

Sensitivity to Majorana neutrinos in $ΔL=2$ decays of $B_c$ meson at LHCb

The possible existence of Majorana neutrinos can be tested through the study of processes where the total lepton number $L$ is violated by two units ($ΔL=2$). In this work, the production of an on-shell Majorana neutrino with a mass around $\sim$ 0.2 GeV to a few GeV is studied in $ΔL= 2$ decays of the $B_c$ meson. We focus on the same-sign di-muon channels: three-body $B_c^- \to π^+μ^-μ^-$ and four-body $B_c^- \to J/ψπ^+μ^-μ^-$ and their experimental sensitivity at the LHCb. In both channels, we find that sensitivities on the branching fraction of the order $\lesssim 10^{-7} \ (10^{-8})$ might be accessible at the LHC run 2 (future LHC run 3), allowing us to set additional and complementary constraints on the parameter space associated with the mass and mixings of the Majorana neutrino. In particular, bounds can be obtained on the mixing $|V_{μN}|^2 \sim \mathcal{O}(10^{-5}-10^{-4})$ that are similar or better than the ones obtained from heavy meson $ΔL=2$ decays: $D_{(s)}^- \to π^+μ^-μ^-$ and $B^- \to π^+μ^-μ^- \ (D^0π^+μ^-μ^-)$.

hep-ph↗

arXiv2012

Heavy flavor production and spectroscopy at LHCb

We summarize the main measurements performed with the LHCb detector on production and spectroscopy in the heavy flavour sector, using data samples recorded during 2010 and 2011 data taking in proton-proton collisions at $\sqrt s=7$\,TeV .

hep-ex↗