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A bstract The Nelson-Barr (NB) mechanism to solve the strong CP problem assumes CP conservation, arranges vanishing θ ¯ at tree-level and requires vector-like quarks (VLQs) to transmit the CP breaking to the SM. We analyze the flavor constraints coming from the presence of one such down type VLQ of NB type by performing a global fit on the relevant flavor observables. A comparison is made to the case of one generic VLQ. We find that the allowed parameter space for the VLQ Yukawa couplings and the mixing to the SM are confined to a region much smaller than in the generic case, making the NB case falsifiable in principle.

A bstract One simple way to lower the scale of the seesaw mechanism that generates neutrino masses is to attribute part of their smallness to a suppressed vacuum expectation value of a second Higgs doublet as in the neutrinophilic 2HDM or in the type IB seesaw model. On that structure we add one charged singlet scalar to induce a chirally enhanced contribution to ( g – 2) μ with the same righthanded neutrinos of the seesaw. We discuss the interplay of generating the necessary contribution to the latter with lepton flavor violation which is also necessarily brought to low scale. We show that it is possible to explain ( g – 2) μ even for heavy neutrino masses of order of a few TeV.

A bstract Leptonic CP violation is yet to be confirmed as an additional source of CP violation in fundamental interactions. We study the case where leptonic CP violation is spontaneous and is induced by the mixing with a heavy charged vector-like lepton (VLL). We show that the non-decoupling of this VLL is linked with the presence of CP violation and its coupling with the SM leptons are partly fixed from the SM Yukawas. Due to the large leptonic mixing angles, these couplings are typically of the same order and there is no flavor preference. Strong but not definitive constraints come from charged lepton flavor violating processes because the VLL can decouple from one or two leptonic flavors in very special points of parameter space. These special points are very sensitive to the neutrino Majorana phases.

A bstract We calculate, in the context of a 3–3–1 model with heavy charged leptons, constraints on some parameters of the extra particles in the model by imposing that their contributions to both the electron and muon ( g − 2) factors are in agreement with experimental data up to 1 σ -3 σ . In order to obtain realistic results we use some of the possible solutions of the left- and right-unitary matrices that diagonalize the lepton mass matrices, giving the observed lepton masses and at the same time allowing to accommodate the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. We show that, at least up to 1-loop order, in the particular range of the space parameter that we have explored, it is not possible to fit the observed electron and muon ( g − 2) factors at the same time unless one of the extra leptons has a mass of the order of 20–40 GeVs and the energy scale of the 331 symmetry to be of around 60–80 TeVs.

We present a model with [Formula omitted] model plus a sterile neutrino and its phenomenological expectations for the production of charged scalars at the compact linear collider. At tree level, our model predicts a total cross section in between 0.1 and [Formula omitted] pb for the [Formula omitted] process, considering all possible mass values for the charged scalar in the CLIC experiment. We also show that this prediction holds regardless of the masses of the other exotic particles and their couplings. We also show that an indirect detection from its effects in the [Formula omitted] + missing energy process is possible under specific conditions, or a direct detection under other circumstances. However, one cannot use this process to study the sterile neutrinos present in this model, given that they have a small influence in the total cross-section for the direct detection of the exotic scalar to be possible.

We present a model with S 3 ⊗ Z 2 model plus a sterile neutrino and its phenomenological expectations for the production of charged scalars at the compact linear collider. At tree level, our model predicts a total cross section in between 0.1 and 10 - 5 pb for the e - e + → H + H - process, considering all possible mass values for the charged scalar in the CLIC experiment. We also show that this prediction holds regardless of the masses of the other exotic particles and their couplings. We also show that an indirect detection from its effects in the e e ¯ → e e ¯ + missing energy process is possible under specific conditions, or a direct detection under other circumstances. However, one cannot use this process to study the sterile neutrinos present in this model, given that they have a small influence in the total cross-section for the direct detection of the exotic scalar to be possible.

In 1956 Reines & Cowan discovered the neutrino using a liquid scintillator detector. The neutrinos interacted with the scintillator, producing light that propagated across transparent volumes to surrounding photo-sensors. This approach has remained one of the most widespread and successful neutrino detection technologies used since. This article introduces a concept that breaks with the conventional paradigm of transparency by confining and collecting light near its creation point with an opaque scintillator and a dense array of optical fibres. This technique, called LiquidO, can provide high-resolution imaging to enable efficient identification of individual particles event-by-event. A natural affinity for adding dopants at high concentrations is provided by the use of an opaque medium. With these and other capabilities, the potential of our detector concept to unlock opportunities in neutrino physics is presented here, alongside the results of the first experimental validation. Liquid scintillator detectors have been used to study neutrinos ever since their discovery in 1956. The authors introduce an opaque scintillator detector concept for future neutrino experiments with increased capacity for particle identification and a natural affinity for doping.

Abstract We present a model with $$S_3 \\otimes \\mathbb {Z}_2$$ S 3 ⊗ Z 2 model plus a sterile neutrino and its phenomenological expectations for the production of charged scalars at the compact linear collider. At tree level, our model predicts a total cross section in between 0.1 and $$10^{-5}$$ 10 - 5 pb for the $$e^- e^+ \\rightarrow H^+ H^-$$ e - e + → H + H - process, considering all possible mass values for the charged scalar in the CLIC experiment. We also show that this prediction holds regardless of the masses of the other exotic particles and their couplings. We also show that an indirect detection from its effects in the $$e \\overline{e} \\rightarrow e \\overline{e}$$ e e ¯ → e e ¯ + missing energy process is possible under specific conditions, or a direct detection under other circumstances. However, one cannot use this process to study the sterile neutrinos present in this model, given that they have a small influence in the total cross-section for the direct detection of the exotic scalar to be possible.

We present a model with$$S_3 \\otimes \\mathbb {Z}_2$$S 3 ⊗ Z 2 model plus a sterile neutrino and its phenomenological expectations for the production of charged scalars at the compact linear collider. At tree level, our model predicts a total cross section in between 0.1 and$$10^{-5}$$10 - 5 pb for the$$e^- e^+ \\rightarrow H^+ H^-$$e - e + → H + H - process, considering all possible mass values for the charged scalar in the CLIC experiment. We also show that this prediction holds regardless of the masses of the other exotic particles and their couplings. We also show that an indirect detection from its effects in the$$e \\overline{e} \\rightarrow e \\overline{e}$$e e ¯ → e e ¯ + missing energy process is possible under specific conditions, or a direct detection under other circumstances. However, one cannot use this process to study the sterile neutrinos present in this model, given that they have a small influence in the total cross-section for the direct detection of the exotic scalar to be possible.

We classify the meson and baryon long lived resonances considering quarks with electric charge 5/3 and \\(-4/3\\) (in units of \\(\\vert e\\vert\\)) predicted by some 3-3-1 models. Some of these exotic resonances have the usual electric charges \\(0,\\pm1\\), others have \\(\\pm(3,4,5)\\), and the lightest ones decaying only into leptons plus known resonances. We propose another heavy \\(SU(3)_H\\) global symmetry under which hadrons involving only exotic quarks can be constructed.