arXiv subjects

Fabián Hernández-Pinto

Publications and source records attributed to Fabián Hernández-Pinto.

3 recordsLinked to original sources

arXiv2026

Disappearing Tracks from Electroweak Vector Dark Matter at the LHC

We study the disappearing-track signature of a spin-1 minimal dark matter candidate transforming in the real five-dimensional representation of $SU(2)_L$ with vanishing hypercharge. Radiative electroweak corrections induce a compressed mass spectrum among the multiplet components, allowing the singly charged state $V^\pm$ to attain a macroscopic lifetime and decay via $V^\pm \to V^0 π^\pm$ inside tracking detectors. We recast the ATLAS search for disappearing tracks with the full Run-2 dataset of $137\text{ fb}^{-1}$, originally targeted at long-lived charginos, computing the tracklet reconstruction probability analytically from the published efficiency so that the full lifetime range is covered. The procedure reproduces the ATLAS limits for pure winos within $6\%$ in mass. The Run-2 data exclude quintuplet masses up to $1080\text{ GeV}$ for proper decay lengths $cτ\simeq 250\text{ mm}$, and $M_V < 630\text{ GeV}$ for a mass splitting of $166\text{ MeV}$. For the radiative mass splitting predicted by the model with a small Higgs-portal coupling, masses between $120\text{ GeV}$ and $240\text{--}300\text{ GeV}$ are excluded. With $3\text{ ab}^{-1}$ and a Run-2-like analysis, the sensitivity would extend to $1750\text{ GeV}$ for vanishing background and to $1530\text{ GeV}$ for a linear extrapolation of the instrumental background.

hep-ph↗

arXiv2025

Probing light neutralinos from pair-produced sleptons with displaced vertices at the high-luminosity LHC

We study light neutralinos ($\tilde χ_1^0$) with masses ranging from 10 GeV to several hundred GeV within the framework of R-parity-violating (RPV) supersymmetry. These light neutralinos can be long-lived, decaying with a macroscopic displacement (order cm) inside the LHC main detectors. Complementing previous works on the subject, here we focus on their production through the electroweak pair production of left-chiral sleptons ($\tilde e_{L}$), with the signal process $pp\to \tilde e^+_{L} \tilde e^-_{L} \to e^+ \tilde χ_1^0 e^- \tilde χ_1^0$. In contrast to the previous study with a singly produced slepton, where the RPV coupling $λ'_{111}$ induces both the production and decay of the light neutralino, in our scenario the production proceeds through Drell-Yan-like processes that are essentially independent of RPV couplings. Correspondingly, we implement a displaced-vertex search strategy for which our numerical analysis shows that the high-luminosity LHC can probe $λ'_{111}$ values up to three orders of magnitude smaller, and neutralino masses up to about four times larger than those accesible in the previously studied single-slepton production scenario.

hep-ph↗

arXiv2024

Searching for light neutralinos with a displaced vertex at the LHC

We study a bino-like light neutralino ($\tilde χ_1^0$) produced at the LHC from the decay of a scalar lepton ($\tilde e_L$) through the process $pp\to \tilde e_{L} \to e\tilde χ_1^0$ in the context of R-parity-violating (RPV) supersymmetry where $\tilde χ_1^0$ is the lightest supersymmetric particle. For small masses and RPV couplings, the neutralino is naturally long-lived and its decay products can be identified as displaced tracks. Following existing searches, we propose a displaced-vertex search strategy for such a light neutralino with a single RPV coupling switched on, $λ'_{111}$, in the mass range $10\,\mbox{GeV} \lesssim m_{\tilde χ_1^0}\lesssim 230\,\mbox{GeV}$. We perform Monte Carlo simulations and conclude that at the high-luminosity LHC, the proposed search can probe values of $λ'_{111}$ down to two orders of magnitude smaller than current bounds and up to 40 times stronger than projected limits from monolepton searches.

hep-ph↗