Browsing by Author "Cottin, Giovanna"

Now showing 1 - 4 of 4
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    Collider probes of real triplet scalar dark matter
    (2021) Chiang, Cheng-Wei; Cottin, Giovanna; Du, Yong; Fuyuto, Kaori; Ramsey-Musolf, Michael J.
    We study discovery prospects for a real triplet extension of the Standard Model scalar sector at the Large Hadron Collider (LHC) and a possible future 100 TeV pp collider. We focus on the scenario in which the neutral triplet scalar is stable and contributes to the dark matter relic density. When produced in pp collisions, the charged triplet scalar decays to the neutral component plus a soft pion or soft lepton pair, yielding a disappearing charged track in the detector. We recast current 13 TeV LHC searches for disappearing tracks, and find that the LHC presently excludes a real triplet scalar lighter than 248 (275) GeV, for a mass splitting of 172 (160) MeV with L = 36 fb(-1). The reach can extend to 497 (520) GeV with the collection of 3000 fb(-1). We extrapolate the 13 TeV analysis to a prospective 100 TeV pp collider, and find that a similar to 3 TeV triplet scalar could be discoverable with L = 30 ab(-1), depending on the degree to which pile up effects are under control. We also investigate the dark matter candidate in our model and corresponding present and prospective constraints from dark matter direct detection. We find that currently XENON1T can exclude a real triplet dark matter lighter than similar to 3 TeV for a Higgs portal coupling of order one or larger, and the future XENON20T will cover almost the entire dark matter viable parameter space except for vanishingly small portal coupling.
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    Displaced heavy neutrinos from Z ' decays at the LHC
    (SPRINGER, 2019) Chiang, Cheng Wei; Cottin, Giovanna; Das, Arindam; Mandal, Sanjoy
    We study the LHC sensitivity to probe a long-lived heavy neutrino N in the context of Z' models. We focus on displaced vertex signatures of N when pair produced via a Z', decaying to leptons and jets inside the inner trackers of the LHC experiments. We explore the LHC reach with current long-lived particle search strategies for either one or two displaced vertices in association with hadronic tracks or jets. We focus on two well-motivated models, namely, the minimal U(1)(B-L) scenario and its U(1)(X) extension. We find that searches for at least one displaced vertex can cover a significant portion of the parameter space, with light-heavy neutrino mixings as low as vertical bar V-lN vertical bar(2) approximate to 10(-17), and l = e, mu accessible across GeV scale heavy neutrino masses.
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    Revisiting the scotogenic model with scalar dark matter
    (2022) Avila, Ivania M.; Cottin, Giovanna; Diaz, Marco A.
    The scotogenic model is a well motivated scenario that provides both an explanation for neutrino masses and for dark matter (DM). We focus on a real scalar DM candidate in this model, produced through standard thermal freeze-out. We analyze the parameter space of the model compatible with the observed DM relic abundance, direct and indirect detection searches, limits from lepton flavour violating decays and constraints from the neutrino sector. As the mass differences of the DM with the neutral and charged states are found to be small, the new scalars and fermions of the theory will have macroscopic lifetimes, and could thus be potentially detected with long-lived particle signatures at colliders. We find regions in the parameter space to be-partially or fully-consistent with the DM relic abundance, and the prediction of a long-lived charged scalar or lightest neutral fermion in the scotogenic scenario, for DM masses below 500 GeV. We discuss on the collider phenomenology in some detail.
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    Searching for light long lived neutralinos at Super-Kamiokande
    (2021) Candia, Pablo; Cottin, Giovanna; Mendez, Andres; Munoz, Victor
    Light neutralinos could be copiously produced from the decays of mesons generated in cosmic-ray air showers. These neutralinos can be long-lived particles in the context of R-parity violating (RPV) supersymmetric models, implying that they could be capable of reaching the surface of the earth and decay within the instrumental volume of large neutrino detectors. In this article, we use atmospheric neutrino data from the Super-Kamiokande experiment to derive novel constraints for the RPV couplings involved in the production of long-lived light neutralinos from the decays of charged D-mesons and kaons. Our results highlight the potential of neutrino detectors to search for long-lived particles, by demonstrating that it is possible to explore regions of parameter space that are not yet constrained by any fixed-target nor collider experiments.