A new seismicity catalogue of the eastern Alps using the temporary Swath-D network

We present a new, consistently processed seismicity catalogue for the eastern and southern Alps based on the temporary dense Swath-D monitoring network. The final catalogue contains 6053 earthquakes for the time period 2017–2019 and has a magnitude of completeness of −1.0 ML. The smallest detected and located events have a magnitude of −1.7 ML. Aimed at the low to moderate seismicity in the study region, we have developed a multi-stage, mostly automatic workflow that combines a priori information from local catalogues and waveform-based event detection, subsequent efficient GPU-based (GPU: graphics processing unit) event search by template matching, P and S arrival time pick refinement, and location in a regional 3-D velocity model. The resulting seismicity distribution generally confirms the previously identified main seismically active domains but provides increased resolution of the fault activity at depth. In particular, the high number of small events additionally detected by the template search contributes to a denser catalogue and provides an important basis for future geological and tectonic studies in this complex part of the Alpine orogen

A Comprehensive Stress Drop Map From Trench to Depth in the Northern Chilean Subduction Zone

We compute stress drops for earthquakes in Northern Chile recorded between 2007 and 2021. By applying two analysis techniques, (a) the spectral ratio (SR) method and (b) the spectral decomposition (SDC) method, a stress drop map for the subduction zone consisting of 51,510 stress drop values is produced. We build an extended set of empirical Green’s functions (EGF) for the SR method by systematic template matching. Outputs are used to compare with results from the SDC approach, where we apply cell-wise obtained global EGF's to compensate for the structural heterogeneity of the subduction zone. We find a good consistency of results of the two methods. The increased spatial coverage and quantity of stress drop estimates from the SDC method facilitate a consistent stress drop mapping of the different seismotectonic domains. Albeit only small differences of median stress drop, strike-perpendicular depth sections clearly reveal systematic variations, with earthquakes at different seismotectonic locations exhibiting distinct values. In particular, interface seismicity is characterized by the lowest observed median value, whereas upper plate earthquakes show noticeably higher stress drop values. Intermediate depth earthquakes show comparatively high average stress drop and a rather strong depth-dependent increase of median stress drop. Additionally, we observe spatio-temporal variability of stress drops related to the occurrence of the two megathrust earthquakes in the study region. The presented study is the first coherent large scale 3D stress drop mapping of the Northern Chilean subduction zone. It provides an important component for further detailed analysis of the physics of earthquake ruptures

Seismotectonics of the Eastern Alps: New insights from earthquake studies within 4D-MB

The recent installation of the dense SWATH-D network in the Eastern Alps, integrated into the broader AlpArray, provides the basis for new detailed and consistent studies of small to moderate seismicity. In the SPP project ’From Top to Bottom – Seismicity, motion patterns and stress distribution in the Alpine crust’ and the follow-up project ’Constraints on quaternary processes in the Eastern Alps from a new detailed image of seismicity’, we have focused on event detection, precise location, analysis of seismicity clustering and detailed source parameter studies, involving methodological advancements and subsequent application to the seismological SWATH-D and AlpArray data. Here, we summarize the main results of our completed and ongoing work: 1. We have developed a new, python-based tool for automated station quality control of dense seismic networks and arrays and applied it successfully to the permanent and temporary AlpArray networks as well as to the denser SWATH-D network (AutoStatsQ, [Petersen et al., 2019]). The toolbox uses a combination of observed and synthetic teleseismic event data to identify and quantify errors in amplitude gain and sensor orientation and to correct the stations accordingly. 2. Based on methodological tests adapted for the complex tectonic setting in the Alps, we have performed centroid moment tensor inversion of seismicity with MW ≥ 3.0 recorded by the AlpArray network and compared the solutions to historical earthquakes, recent seismicity, published focal mechanisms, and GNSS deformation data ([Petersen et al., 2021]). We additionally applied epicenter clustering to resolve in detail the heterogeneity of tectonic movement. Thrust faulting is dominant in the Friuli area of the eastern Southern Alps, related to the N–S convergence of the Eurasian and Adriatic plate and counterclockwise rotation of Adria relative to Europe. Strikeslip faulting with similarly oriented P- axes is observed along the northern margin of the Central Alps and in the northern Dinarides, consistent with right-lateral strike-slip faults and high shear strain rates. The NW Alps exhibit deviant behavior, with NW–SE-striking normal faulting events and NE–SW-oriented T- axes. Faulting styles in the SW Alps are more heterogeneous, with a majority of earthquakes related to an extensional stress regime. 3. We have designed a workflow which combines a priori information from local catalog and waveformbased event detection, subsequent GPU-based event search by template matching, P & S arrival time pick refinement and location in a regional 3-D velocity model. Application to the SWATH-D data provided for the first time a consistently processed seismicity catalog for the Eastern and Southern Alps, which has a magnitude of completeness of −1.0 ML, involves event classification and includes > 6, 000 earthquakes [Hofman et al., 2023a]. The newly revealed clusters better illuminate the fault structures at depth, and we detected and located additional, mostly weak events, a part of them pointing to small, but active upper crustal deformation in the Dolomite indenter, along the Pustertal-Gailtal Fault and in the Tauern window. 4. In our ongoing work, we characterize the earthquake distribution in more detail, using novel approaches from Graph theory, waveform similarity based clustering and stacked- waveform moment tensor Inversion [Hofman et al., 2023b], [Petersen et al., 2020], [Petersen et al., 2023]

CMS physics technical design report : Addendum on high density QCD with heavy ions

Peer reviewe

Objectively Measured Physical Activity Is Inversely Associated With Nonalcoholic Fatty Liver Disease: The Rotterdam Study

INTRODUCTION: The disease burden of nonalcoholic fatty liver disease (NAFLD) increases rapidly, in line with the obesity pandemic. Physical activity has been linked to a lower risk of NAFLD. However, the impact of different intensities of activity and sedentary behavior and whether their effects on NAFLD are explained by metabolic health remain unclear. METHODS: We performed cross-sectional analyses within the population-based Rotterdam Study cohort. Abdominal ultrasound and accelerometry data were collected between 2009 and 2014. NAFLD was defined as hepatic steatosis diagnosed by ultrasound, in the absence of secondary causes for steatosis: viral hepatitis, steatogenic drugs, and excessive alcohol. We categorized accelerometry data into sedentary time and light, moderate, and vigorous physical activities. RESULTS: We included 667 participants (aged 63.3 ± 6.3 years, 53% female individuals), and 34.3% had NAFLD. Total physical activity was associated with lower NAFLD prevalence adjusted for demographic, lifestyle, and socioeconomic factors (odds ratio: 0.958 per 10 min/d, 95% confidence interval [CI]: 0.929-0.986). More intensive physical activity was more strongly associated with lower NAFLD prevalence: odds ratios for light, moderate, and vigorous physical activities were 0.931 (95% CI: 0.882-0.982), 0.891 (95% CI: 0.820-0.967), and 0.740 (95% CI: 0.600-0.906) per 10 min/d, respectively. These associations were explained by metabolic health, particularly homeostatic model assessment of insulin resistance (proportion mediated: 0.59, P < 0.001) and waist circumference (proportion mediated: 1.08, P < 0.001). Beyond this indirect effect, no direct effect could be demonstrated (P = 0.282-0.827). DISCUSSION: Physical activity at each intensity is inversely associated with NAFLD prevalence, with larger effects for higher intensities of physical activity. This association is mediated by better metabolic health, mainly lower insulin resistance and waist circumference. Physical activity should therefore be incorporated into NAFLD disease management and prevention programs

Enhanced deuteron coalescence probability in jets

The transverse-momentum (pT) spectra and coalescence parameters B2 of (anti)deuterons are measured in pp collisions at s√=13 TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest pT in the event (pleadT>5 GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions and the jet signal is obtained as the difference between the Toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the Transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase-space distance between nucleons inside the jet cone as compared to the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase space distributions of nucleons are generated using PYTHIA 8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in PYTHIA 8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the BJet2 is not reproduced by the models, which instead give a decreasing trend

Forward rapidity J/ψ production as a function of charged-particle multiplicity in pp collisions at s \sqrt{s} = 5.02 and 13 TeV

International audienceThe production of J/ψ is measured as a function of charged-particle multiplicity at forward rapidity in proton-proton (pp) collisions at center-of-mass energies $\sqrt{s}$ = 5.02 and 13 TeV. The J/ψ mesons are reconstructed via their decay into dimuons in the rapidity interval (2.5 < y < 4.0), whereas the charged-particle multiplicity density (dN$_{ch}$/dη) is measured at midrapidity (|η| < 1). The production rate as a function of multiplicity is reported as the ratio of the yield in a given multiplicity interval to the multiplicity-integrated one. This observable shows a linear increase with charged-particle multiplicity normalized to the corresponding average value for inelastic events (dN$_{ch}$/dη/〈dN$_{ch}$/dη〉), at both the colliding energies. Measurements are compared with available ALICE results at midrapidity and theoretical model calculations. First measurement of the mean transverse momentum (〈p$_{T}$〉) of J/ψ in pp collisions exhibits an increasing trend as a function of dN$_{ch}$/dη/〈dN$_{ch}$/dη〉 showing a saturation towards high charged-particle multiplicities.[graphic not available: see fulltext

Two-particle transverse momentum correlations in pp and p–Pb collisions at energies available at the CERN Large Hadron Collider

Two-particle transverse momentum differential correlators, recently measured in Pb--Pb collisions at energies available at the CERN Large Hadron Collider (LHC), provide an additional tool to gain insights into particle production mechanisms and infer transport properties, such as the ratio of shear viscosity to entropy density, of the medium created in Pb-Pb collisions. The longitudinal long-range correlations and the large azimuthal anisotropy measured at low transverse momenta in small collision systems, namely pp and p-Pb, at LHC energies resemble manifestations of collective behaviour. This suggests that locally equilibrated matter may be produced in these small collision systems, similar to what is observed in Pb-Pb collisions. In this work, the same two-particle transverse momentum differential correlators are exploited in pp and p-Pb collisions at s√=7 TeV and sNN−−−√=5.02 TeV, respectively, to seek evidence for viscous effects. Specifically, the strength and shape of the correlators are studied as a function of the produced particle multiplicity to identify evidence for longitudinal broadening that might reveal the presence of viscous effects in these smaller systems. The measured correlators and their evolution from pp and p--Pb to Pb--Pb collisions are additionally compared to predictions from Monte Carlo event generators, and the potential presence of viscous effects is discussed

Σ(1385)± resonance production in Pb–Pb collisions at √sNN = 5.02 TeV

Hadronic resonances are used to probe the hadron gas produced in the late stage of heavy-ion collisions since they decay on the same timescale, of the order of 1 to 10 fm/c, as the decoupling time of the system. In the hadron gas, (pseudo)elastic scatterings among the products of resonances that decayed before the kinetic freeze-out and regeneration processes counteract each other, the net effect depending on the resonance lifetime, the duration of the hadronic phase, and the hadronic cross sections at play. In this context, the Σ(1385)± particle is of particular interest as models predict that regeneration dominates over rescattering despite its relatively short lifetime of about 5.5 fm/c. The first measurement of the Σ(1385)± resonance production at midrapidity in Pb-Pb collisions at sNN−−−√=5.02 TeV with the ALICE detector is presented in this Letter. The resonances are reconstructed via their hadronic decay channel, Λπ, as a function of the transverse momentum (pT) and the collision centrality. The results are discussed in comparison with the measured yield of pions and with expectations from the statistical hadronization model as well as commonly employed event generators, including PYTHIA8/Angantyr and EPOS3 coupled to the UrQMD hadronic cascade afterburner. None of the models can describe the data. For Σ(1385)±, a similar behaviour as K∗(892)0 is observed in data unlike the predictions of EPOS3 with afterburner