Neutron exposure and neutron flux in Asymptotic Giant Branch stars: a study of neutron capture cross sections of Zr isotopes

Nuclear astrophysics is an interdisciplinary branch of physics involving close collaboration among researchers in various subfields of nuclear physics and astrophysics, with significant emphasis in areas such as stellar modeling, measurement and theoretical estimation of nuclear reaction rates, cosmology, cosmochemistry, gamma ray, optical and X-ray astronomy. In general terms, nuclear astrophysics aims to understand the origin of the chemical elements and the energy generation in stars. This work concerns the measurements of the neutron capture cross sections of 90,91,92,93,94,96Zr isotopes, performed at the time-of-flight facilities n_TOF at CERN and GELINA at IRMM and their implication in stellar modeling

The H and D Polarized Target for Spin–Filtering Measurements at COSY

In the main frame of the PAX (Polarized Antiproton eXperiments) collaboration, which engaged the challenging purpose of polarizing antiproton beams, the possibility to have H or D polarized targets requires a daily switchable source and its diagnostics: mainly change is a dual cavity tunable for H and D. The commissioning of PAX has been fullfilled, for the transverse case, on the COSY (COoler SYnchrotron) proton ring, achieving milestones on spin–dependent cross–section measurements. Now the longitudinal case could provide sensitive polarization results. An H or D source allows the exploration of the spin–filtering process with a deuterium polarized target, and opens new chances for testing Time Reversal Invariance at COSY (TRIC)

First Search for Axion-Like Particles in a Storage Ring Using a Polarized Deuteron Beam

Based on the notion that the local dark-matter field of axions or axion-like particles (ALPs) in our Galaxy induces oscillating couplings to the spins of nucleons and nuclei (via the electric dipole moment of the latter and/or the paramagnetic axion-wind effect), we performed the first experiment to search for ALPs using a storage ring. For that purpose, we used an in-plane polarized deuteron beam stored at the Cooler Synchrotron COSY, scanning momenta near 970 MeV/c. This entailed a scan of the spin precession frequency. At resonance between the spin precession frequency of deuterons and the ALP-induced EDM oscillation frequency there will be an accumulation of the polarization component out of the ring plane. Since the axion frequency is unknown, the momentum of the beam and consequently the spin precession frequency were ramped to search for a vertical polarization change that would occur when the resonance is crossed. At COSY, four beam bunches with different polarization directions were used to make sure that no resonance was missed because of the unknown relative phase between the polarization precession and the axion/ALP field. A frequency window of 1.5-kHz width around the spin precession frequency of 121 kHz was scanned. We describe the experimental procedure and a test of the methodology with the help of a radiofrequency Wien filter located on the COSY ring. No ALP resonance was observed. As a consequence an upper limit of the oscillating EDM component of the deuteron as well as its axion coupling constants are provided.Comment: 25 pages, 24 figures, 7 tables, 67 reference

First Results of the 140^{140}Ce(n,γ)141^{141}Ce Cross-Section Measurement at n_TOF

An accurate measurement of the $^{140}$Ce(n,γ) energy-dependent cross-section was performed at the n_TOF facility at CERN. This cross-section is of great importance because it represents a bottleneck for the s-process nucleosynthesis and determines to a large extent the cerium abundance in stars. The measurement was motivated by the significant difference between the cerium abundance measured in globular clusters and the value predicted by theoretical stellar models. This discrepancy can be ascribed to an overestimation of the $^{140}$Ce capture cross-section due to a lack of accurate nuclear data. For this measurement, we used a sample of cerium oxide enriched in $^{140}$Ce to 99.4%. The experimental apparatus consisted of four deuterated benzene liquid scintillator detectors, which allowed us to overcome the difficulties present in the previous measurements, thanks to their very low neutron sensitivity. The accurate analysis of the p-wave resonances and the calculation of their average parameters are fundamental to improve the evaluation of the $^{140}$Ce Maxwellian-averaged cross-section

First Results of the 140^{140}Ce(n,γ)141^{141}Ce Cross-Section Measurement at n_TOF

An accurate measurement of the $^{140}$Ce(n,γ) energy-dependent cross-section was performed at the n_TOF facility at CERN. This cross-section is of great importance because it represents a bottleneck for the s-process nucleosynthesis and determines to a large extent the cerium abundance in stars. The measurement was motivated by the significant difference between the cerium abundance measured in globular clusters and the value predicted by theoretical stellar models. This discrepancy can be ascribed to an overestimation of the $^{140}$Ce capture cross-section due to a lack of accurate nuclear data. For this measurement, we used a sample of cerium oxide enriched in $^{140}$Ce to 99.4%. The experimental apparatus consisted of four deuterated benzene liquid scintillator detectors, which allowed us to overcome the difficulties present in the previous measurements, thanks to their very low neutron sensitivity. The accurate analysis of the p-wave resonances and the calculation of their average parameters are fundamental to improve the evaluation of the $^{140}$Ce Maxwellian-averaged cross-section

Non-invasive neuromodulation can reduce aggressive behaviors in humans: A critical perspective

: Containing aggressive behavior is an ongoing challenge in modern society. Aggressiveness is a multi-level construct that can be driven by emotions (reactive aggression) or can be "cold-blooded" and goal-directed (proactive). Aggressive behavior could arise because of a misjudgment of others' intentions or can follow frontal brain lesions leading to a reduction of impulse control and emotion regulation. In the last few years, interventional and basic research studies adopting Non-Invasive Brain Stimulation (NIBS) have significantly risen. Those techniques have been used both in healthy people, to better understand the role of certain brain regions in psychological processes, and in aggressive subjects to improve their symptoms. From an overview of the literature, focusing on the paper that uses transcranial direct current stimulation (tDCS) to reduce aggressiveness, it emerges that tDCS can (i) enhance facial emotion expression recognition, (ii) improve impulses control, and (iii) affect approach/withdrawal motivation. The current work shows the strengths and weaknesses of tDCS intervention on aggressive individuals, suggesting that this instrument could be adopted on violent people, and paves the way for intervention in some applied settings such as prison

The LHCspin project

The goal of LHCspin is to develop, in the next few years, innovative solutions and cutting-edge technologies to access the field of spin physics by exploring a unique kinematic regime and by exploiting new reaction processes. In fact, a polarized gaseous target, operated in combination with the high-energy, high-intensity LHC beams and the highly performing LHCb particle detector, has the potential to open new physics frontiers and deepen our understanding of the intricacies of the strong interaction in the non-perturbative regime of QCD. This configuration, with center of mass energies up to 115 GeV, using both proton and heavy-ion beams covers a wide backward rapidity region, including the poorly explored high x-Bjorken and high x -Feynman regimes. This ambitious task poses its basis in the recent installation of an unpolarized gas target (SMOG2) in the LHCb spectrometer resulting not only in a unique project itself, but also in an invaluable playground for its polarized upgrade. An overview of the physics potential, a description of the LHCspin experimental setup, and the first output the of SMOG2 system are presented