A search for heavy resonances decaying into a pair of Z bosons leading to ℓ+ℓ−ℓ′+ℓ′− and ℓ+ℓ−νν¯ final states, where ℓ stands for either an electron or a muon, is presented. The search uses ...proton–proton collision data at a centre-of-mass energy of 13 TeV collected from 2015 to 2018 that corresponds to the integrated luminosity of 139 fb−1 recorded by the ATLAS detector during Run 2 of the Large Hadron Collider. Different mass ranges spanning 200 GeV to 2000 GeV for the hypothetical resonances are considered, depending on the final state and model. In the absence of a significant observed excess, the results are interpreted as upper limits on the production cross section of a spin-0 or spin-2 resonance. The upper limits for the spin-0 resonance are translated to exclusion contours in the context of Type-I and Type-II two-Higgs-doublet models, and the limits for the spin-2 resonance are used to constrain the Randall–Sundrum model with an extra dimension giving rise to spin-2 graviton excitations.
Facial threat is associated with changes in limbic activity as well as modifications in the cortical face-related N170. It remains unclear if task-irrelevant threat modulates the response to a ...subsequent facial stimulus, and whether the amygdala's role in early threat perception is independent and direct, or modulatory. In 19 participants, crowds of emotional faces were followed by target faces and a rating task while simultaneous EEG-fMRI were recorded. In addition to conventional analyses, fMRI-informed EEG analyses and fMRI dynamic causal modeling (DCM) were performed. Fearful crowds reduced EEG N170 target face amplitudes and increased responses in a fMRI network comprising insula, amygdala and inferior frontal cortex. Multimodal analyses showed that amygdala response was present ∼60 ms before the right fusiform gyrus-derived N170. DCM indicated inhibitory connections from amygdala to fusiform gyrus, strengthened when fearful crowds preceded a target face. Results demonstrated the suppressing influence of task-irrelevant fearful crowds on subsequent face processing. The amygdala may be sensitive to task-irrelevant fearful crowds and subsequently strengthen its inhibitory influence on face-responsive fusiform N170 generators. This provides spatiotemporal evidence for a feedback mechanism of the amygdala by narrowing attention in order to focus on potential threats.
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