Examinando por Autor "Siqueira, C."

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    Flavor changing interactions confronted with meson mixing and hadron colliders
    (American Physical Society, 2023-03) Cárcamo Hernández, A. E.; Duarte, L.; De Jesus, A.S.; Kovalenko, S.; Queiroz, F.S.; Siqueira, C.; Oviedo-Torres, Y.M.; Villamizar, Y.
    We have witnessed some flavor anomalies appearing in the past years, and explanations based on extended gauge sectors are among the most popular solutions. These beyond the Standard Model (SM) theories often assume flavor-changing interactions mediated by new vector bosons. Still, at the same time, they could yield deviations from the SM in the K0 − K¯ 0, D0 − D¯ 0, B0 d − B¯ 0 d, and B0 s − B¯ 0 s meson systems. Using up-to-date data on the mass difference of these meson systems, we derive lower mass bounds on vector mediators for two different parametrizations of the quark mixing matrices. Focusing on a well-motivated model based on the fundamental representation of the weak SU(3) gauge group, we put our findings into perspective with current and future hadron colliders to conclude that meson mass systems can give rise to bounds much more stringent than those from high-energy colliders and that recent new physics interpretations of the b → s and RðD Þ anomalies are disfavored
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    Rare kaon decay to missing energy: Implications of the NA62 result for a Z′ model
    (American Physical Society, 2021-06) De Melo, Téssio B.; Kovalenko, Sergey; Queiroz, Farinaldo S.; Siqueira, C.; Villamizar, Yoxara S.
    Meson decays offer a good opportunity to probe new physics. The rare kaon decay K+→π+νν¯ is one of the cleanest of them and, for this reason, is rather sensitive to new physics, in particular, vector mediators. The NA62 Collaboration, running a fixed-target experiment at CERN, recently reported an unprecedented sensitivity to this decay, namely a branching fraction of BR(K+→π+νν¯)=(11-3.5+4.0)×10-11 at 68% C.L. Vector mediators that couple to neutrinos may yield a sizeable contribution to this decay. Motivated by the new measurement, we interpret this result in the context of a concrete Z′ model, and put our findings into perspective with the correlated KL→π0νν¯ decay measured by the KOTO Collaboration, current, and future colliders, namely the High-Luminosity and High-Energy Large Hadron Collider. © 2021 authors. Published by the American Physical Society.
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    Vectorlike leptons and inert scalar triplet: Lepton flavor violation, g-2, and collider searches
    (American Physical Society, 2020-08) De Jesus, A.S.; Kovalenko, S.; Queiroz, F.S.; Siqueira, C.; Sinha, K.
    We investigate simplified models involving an inert scalar triplet and vectorlike leptons that can account for the muon g-2 anomaly. These simplified scenarios are embedded in a model that features W' and Z' bosons, which are subject to stringent collider bounds. The constraints coming from the muon g-2 anomaly are put into perspective with collider bounds, as well as bounds coming from lepton flavor violation searches. The region of parameter space that explains the g-2 anomaly is shown to be within reach of lepton flavor violation probes and future colliders such as HL-LHC and HE-LHC. © 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.