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Measurement of multidifferential cross sections for dijet production in proton–proton collisions at
No full textA measurement of the dijet production cross section is reported based on proton–proton collision data collected in 2016 at by the CMS experiment at the CERN LHC, corresponding to an integrated luminosity of up to 36.3. Jets are reconstructed with the anti- algorithm for distance parameters of and 0.8. Cross sections are measured double-differentially (2D) as a function of the largest absolute rapidity of the two jets with the highest transverse momenta and their invariant mass , and triple-differentially (3D) as a function of the rapidity separation , the total boost , and either or the average of the two jets. The cross sections are unfolded to correct for detector effects and are compared with fixed-order calculations derived at next-to-next-to-leading order in perturbative quantum chromodynamics. The impact of the measurements on the parton distribution functions and the strong coupling constant at the mass of the boson is investigated, yielding a value of
Exact Evaluation of Hexagonal Spin-Networks for Topological Quantum Neural Networks
No full textThe physical scalar product between spin-networks has been shown to be a fundamental tool in the theory of topological quantum neural networks (TQNNs). These are a class of quantum neural networks supported on graphs and related to topological quantum field theory (TQFT), which have been previously introduced by the authors, recovering deep neural networks (DNNs) as their semiclassical limit. However, the effective evaluation of the scalar product remains an obstacle for the applicability of the theory. Inspired by decimation techniques for the computation of the partition function in statistical mechanics, an analytical technique is introduced for the exact evaluation of hexagonal spin-networks of arbitrary size, and describe the corresponding algorithm for the evaluation of the physical scalar product defined by Noui and Perez. The transition amplitudes on certain classes of spin-networks with both classical and quantum recoupling are investigated, obtaining a "continuous" spectrum of the transitions for the former and a discrete one for the latter. The theoretical and computational framework is expected to impact applications in string/tensor-networks for solid state physics, lattice gauge theories, and quantum gravity approaches
COSMICA: a novel parallel GPU code for Cosmic Rays propagation in heliosphere
Full text link<p>The complex structure of interplanetary magnetic fields and their variability, due to solar activity, make it necessary to compute the Cosmic Ray (CR) modulation with numerical simulations. COde for a Speedy Monte Carlo (MC) Involving Cuda Architecture (COSMICA) is a MC code, solving backward-in-time the system of Stochastic Differential Equations (SDE) equivalent to the Parker Transport Equation (PTE). The Graphics Processing Unit (GPU) parallelization of COSMICA code is a game changer in this field because it reduces the computational time of a standard simulation from the order of hundred of minutes to few of them. Furthermore, the code is capable of distributing the computations on clusters of machines with multiple GPUs, opening the way for scaling. In COSMICA we implemented the synchronous broadcasting of memory access for evolving variable samples, the rounding of virtual particle set numbers, to fulfil the GPU blocks, and the exploitation of shared memory to free registers. Furthermore, we compactify the mathematical computations and pass to the lighter momentum formulation of SDE. The first porting of the code on GPU architecture brings it to a speed-up of 40X. The successful optimizations bring 1.5X speed-up.</p>
Dataset related to \"Brain Dynamics Complexity as a Signature of Cognitive Decline in Parkinson's Disease\
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ASTAROTH-Cryogenic_Chamber_Design&Test_Report
No full text<p>In order to validate the design of the cryogenic chamber of the ASTAROTH experiment, finite element analysis and mechanical material characterisation tests were carried out under cryogenic conditions.</p>\n\n<p>This document summarises the results of the analyses and tests conducted jointly by the INFN Milano Design and Mechanical Workshop Service and at the INFN LASA Laboratory.</p>
Banca dati geologica F. 89 Courmayeur scala 1:25.000
Full text link<p>Banca Dati alla scala 1:25.000 della Carta Geologica prodotta nell'ambito del Progetto CARG in formato GeoPackage. I layer presenti si riferiscono alle Unità cartografabili geologiche, agli Elementi geomorfologici e alle Risorse e Prospezioni. Gli strati informativi sono rappresentati in accordo con la simbologia prevista dalla normativa del Progetto CARG.</p>
Quest for CMB spectral distortions to probe the scalar-induced gravitational wave background interpretation of pulsar timing array data
No full textGravitational waves (GW) sourced by second-order primordial curvature fluctuations are among the favored models fitting the recent pulsar timing array (PTA) measurement of a stochastic GW background (SGWB). We study how spectral distortions (SDs) and anisotropies of the cosmic microwave background (CMB) can constrain such scalar fluctuations. Whereas COBE FIRAS data have no sufficient sensitivity to probe the PTA log-normal hypothesis, we show how future PIXIE-like experiments can detect the CMB SDs from the scalar-induced interpretation of the SGWB in PTA data. We finally show how the transformative synergy between PTA data and future CMB SD measurements is important for reconstructing primordial fluctuations at these small scales
First direction sensitive search for dark matter with a nuclear emulsion detector at a surface site
No full textFine-grained nuclear emulsion films have been developed as a tracking detector with nanometric spatial resolution to be used in direction-sensitive dark matter searches, thanks to novel readout technologies capable of exploiting this unprecedented resolution. Emulsion detectors are time insensitive. Therefore, a directional dark matter search with such detector requires the use of an equatorial telescope to absorb the Earth rotation effect. We have conducted for the first time a directional dark matter search in an unshielded location, at the sea level, by keeping an emulsion detector exposed for 39 days on an equatorial telescope mount. The observed angular distribution of the data collected during an exposure equivalent to 0.59 g days agrees with the background model and an exclusion plot was then derived in the dark matter mass and cross-section plane: cross-sections higher than 9.2 × 10 cm and 1.2 × 10 cm were excluded for a dark matter mass of 10 GeV/c and 100 GeV/c, respectively.This is the first direction sensitive search for dark matter with a solid-state, particle tracking detector
COSMICA: A GPU-Optimized Code for Solar Modulation Studies
Full text link<p>We present COSMICA, an opensource high-performance GPU-accelerated numerical code for modeling cosmic ray solar modulation, and its application to study CR diffusion parameters. Developed within the framework of the ICSC-Italian Research Center on High-Performance Computing, Big Data and Quantum Computing (Spoke-3), COSMICA is undergoing continuous software optimization to maximize efficiency on NVIDIA architectures. COSMICA is coupled with SDEGnO, another ICSC project, designed for the efficient parameter tuning, exploring the large parameter space in solar modulation studies. As a first physical use-case study, we exploit COSMICA to investigate Forbush decreases (FDs), which are transient cosmic ray intensity reductions caused by interplanetary disturbances. The analysis leverages the high-precision daily measurements from AMS-02, which provide cosmic ray fluxes across a wide range of rigidities. The ability to simultaneously study not only protons but also helium isotopes offers complementary insights into charge- and mass-dependent transport effects. By analyzing FD events, we assess localized variations in diffusion parameters and their impact on cosmic ray transport. The results confirm the stability of the rigidity dependence of the diffusion tensor, supporting the use of FDs as probes of localized well constrained heliospheric conditions. The computational efficiency of COSMICA paves the way for large-scale simulations, systematic FD catalogue analysis and a more in-depth understanding of the parameter that regulates the solar modulation, together with their dependencies.</p>