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We study damping signatures at the Jiangmen Underground Neutrino Observatory (JUNO), a medium-baseline reactor neutrino oscillation experiment. These damping signatures are motivated by various new physics models, including quantum decoherence, ν3 decay, neutrino absorption, and wave packet decoherence. The phenomenological effects of these models can be characterized by exponential damping factors at the probability level. We assess how well JUNO can constrain these damping parameters and how to disentangle these different damping signatures at JUNO. Compared to current experimental limits, JUNO can significantly improve the limits on τ3/m3 in the ν3 decay model, the width of the neutrino wave packet σx, and the intrinsic relative dispersion of neutrino momentum σrel.

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<p>The Middle Allochthon of the Scandinavian Caledonides represents the Neoproterozoic distal continental passive margin intruded by a dyke swarm with minor Mesoproterozoic and Paleoproterozoic orthogneiss. Locally, it carries early Neoproterozoic plutonic rocks. For this work, we collected geochronological and geochemical data and carried out thermodynamic modelling on a variety of lithologies from the Vássačorru Igneous Complex (VIC) and surrounding rocks of the Mårma terrane of the Seve Nappe Complex (SNC) in the Kebnekaise area, northern Swedish Caledonides.</p> <p>U-Pb zircon LA-ICP-MS geochronology yielded crystallization ages of c. 864±3 Ma (MSWD=0.92; n=9) and 856±3 Ma (MSWD=2.8; n=10) for the Vistas Granite and a gabbro from the VIC, respectively. A granodioritic intrusion yielded an age of 850±1 Ma (MSWD=1.5; n=38), whereas a granitic dyke and mylonitic orthogneiss yielded ages of 840±7 Ma (MSWD=4.3; n=50) and 835±8 Ma (MSWD=0.71; n=24), respectively. Younger populations of zircon at c. 626–610 Ma were dated in a banded amphibolite and the Aurek gabbro. Rare earth element (REE) geochemistry from felsic lithologies in the VIC indicate lower crustal contamination, while the REE pattern for the VIC gabbro suggests an N-MORB affinity for light REE and enrichment in the heavy REE due to crustal assimilation. The banded amphibolite records pressure-temperature (P–T) conditions in the melt stability field at 10.5–12.0 kbar and 600–680 °C. The Aurek gabbro records high-pressure metamorphism at 11.8–12.6 kbar and 480–565 °C. Phase equilibrium modelling of the peak metamorphic assemblage in the mylonitic orthogneiss yielded 11.2–11.7 kbar and 560–610 °C, while the retrograde assemblage yielded 7.4–8.1 kbar and 615–675 °C. Furthermore, P–T estimates of 6.5–7.5 kbar at 600–625 °C were obtained for the Vistas Granite.</p> <p>The geochronological data indicate that the Kebnekaise region experienced several magmatic pulses during the Neoproterozoic. These geochronological and geochemical data suggest that the magmatic event responsible for the emplacement of the VIC is related to an attempted break-up of Rodinia between c. 864–835 Ma. The ages obtained from banded amphibolite and the Aurek gabbro represent the emplacement of mafic protoliths during the real break-up at c. 626–610 Ma.</p> <p>Two metamorphic ages were obtained: one, c. 598 Ma, from the banded amphibolite, is interpreted as the age of the high temperature metamorphism in the melt stability field. The second, c. 443 Ma, from the mylonitic orthogneiss, is interpreted as the age of the amphibolite facies metamorphic condition reached during the collisional stage. The age of the metamorphic peak was not detected. However, the P–T estimates for the mylonitic orthogneiss and the Aurek gabbro are comparable with the results from other lithologies within the Kebnekaise region and in the northern Seve Nappe Complex. For this reason, we hypothesize that the age of the metamorphic peak is at c. 490–480 Ma.</p> <p>This research is funded by the National Science Centre (Poland) project no. 2019/33/B/ST10/01728 to Majka.</p>

The upper gneiss unit is exposed in the northernmost Seve Nappe Complex (SNC) in the Scandinavian Caledonides. To investigate the Caledonian tectonic history of the unit, in-situ white mica and biotite 40 Ar/ 39 Ar geochronology was applied to a leucogranite and two paragneisses. The leucogranite exhibits low strain traits. Biotite porphyroblasts yielded a cooling age of 459 ± 2 Ma. White mica that replace biotite and plagioclase provided a crystallization age of 436 ± 5 Ma. White mica in both paragneisses exhibit high strain characteristics associated with top-to-E sense of shear. One paragneiss provided dispersed late Cambrian to Late Ordovician dates with the youngest approximating deformation at 459 ± 2 Ma. The older dates are interpreted to reflect 40 Ar inherited from a previous metamorphic event. The second paragneiss yielded a deformation age of 434 ± 2 Ma. The collective dataset is interpreted to record: 1) exhumation of the upper gneiss unit at c. 459 Ma, 2) deformation and fluid-infiltration at c. 434 Ma during continental collision. The events closely resemble the deformation histories of other northern SNC terranes. Synthesizing these results with other northern SNC terranes suggests that the Baltican margin underwent oblique, south-to-north subduction during late Cambrian time. Thematic collection: This article is part of the Caledonian Wilson cycle collection available at: https://www.lyellcollection.org/topic/collections/the-caledonian-wilson-cycle Supplementary material: https://doi.org/10.6084/m9.figshare.c.6639993