A systematic analysis of deuteron breakup Torabi, F; Carlson, B V
Journal of physics. G, Nuclear and particle physics,
04/2023, Letnik:
50, Številka:
4
Journal Article
Recenzirano
Abstract
Inclusive breakup cross sections for deuterons incident on a wide range of nuclei at different incident energies are studied. In our analysis, we use the post-form distorted-wave-Born ...approximation (DWBA) to calculate the elastic and nonelastic breakup cross sections. We also calculate exciton and statistical compound-nucleus model cross sections to account for pre-equilibrium and equilibrium emissions. The calculations are performed using the code EMPIRE and are compared to the available experimental data. The comparisons of the integrated cross sections reveal a generally good agreement between the calculations and the data. However, systematic discrepancies are observed between the calculated double differential neutron and proton cross sections and the data, especially for heavier targets. Possible reasons for the disagreements between the theoretical predictions and the experimental data are discussed.
The REGINA code calculates the São Paulo potential version 2 (SPP2) and the Brazilian nuclear potential (BNP). The code also provides nuclear densities obtained from the Dirac-Hartree-Bogoliubov ...model, which are used to calculate the nuclear potentials. Elastic scattering cross sections are obtained within the context of the optical model, with different options for the real and imaginary parts of the optical potential. In this manuscript, we provide a summary of the theoretical framework and information about the use of the code.
Program Title: REGINA.f
CPC Library link to program files:https://doi.org/10.17632/vfkkjb8dv7.1
Licensing provisions: GPLv3
Programming language: Fortran-77
Nature of problem: We provide a code to calculate the nuclear potential between two nuclei according to two different models: the São Paulo potential version 2 (SPP2), that includes a dependence on the relative velocity between the nuclei, and the velocity independent Brazilian nuclear potential (BNP). These potentials assume the effective nuclear interactions proposed in 1,2, and are obtained within the double-folding approach with nuclear densities calculated through the Dirac-Hartree-Bogoliubov model 3.
Solution method: The code involves two files containing previously calculated results for theoretical neutron and proton distributions and also experimental charge densities obtained from electron scattering experiments. These results are used to obtain matter densities through convolution using Fourier transforms. The Fourier transform method is also employed to obtain the double-folding potentials. Integration of the Schrödinger equation with a complex optical potential is performed using the Cowell method 4,5. With this, for a given system and energy, we obtain the S-matrix and the elastic scattering cross sections.
Additional comments including restrictions and unusual features: The maximum angular momentum supported in the optical model calculations is 2000.
We present an interpretable implementation of the autoencoding algorithm, used as an anomaly detector, built with a forest of deep decision trees on FPGA, field programmable gate arrays. Scenarios at ...the Large Hadron Collider at CERN are considered, for which the autoencoder is trained using known physical processes of the Standard Model. The design is then deployed in real-time trigger systems for anomaly detection of unknown physical processes, such as the detection of rare exotic decays of the Higgs boson. The inference is made with a latency value of 30 ns at percent-level resource usage using the Xilinx Virtex UltraScale+ VU9P FPGA. Our method offers anomaly detection at low latency values for edge AI users with resource constraints.
The Aerosol Robotic Network (AERONET) has been providing high-quality retrievals of aerosol optical properties from the surface at worldwide locations for more than a decade. Many sites have ...continuous and consistent records for more than 10 years, which enables the investigation of long-term trends in aerosol properties at these locations. In this study, we present the results of a trend analysis at selected stations with long data records. In addition to commonly studied parameters such as aerosol optical depth (AOD) and Ångström exponent (AE), we also focus on inversion products including absorption aerosol optical depth (ABS), single-scattering albedo (SSA) and the absorption Ångström exponent (AAE). Level 2.0 quality assured data are the primary source. However, due to the scarcity of level 2.0 inversion products resulting from the strict AOD quality control threshold, we have also analyzed level 1.5 data, with some quality control screening to provide a reference for global results. Two statistical methods are used to detect and estimate the trend: the Mann–Kendall test associated with Sen's slope and linear least-squares fitting. The results of these statistical tests agree well in terms of the significance of the trend for the majority of the cases. The results indicate that Europe and North America experienced a uniform decrease in AOD, while significant (>90%) increases in these two parameters are found for North India and the Arabian Peninsula. The AE trends turn out to be different for North America and Europe, with increases for the former and decreases for the latter, suggesting opposite changes in fine/coarse-mode fraction. For level 2.0 inversion parameters, Beijing and Kanpur both experienced an increase in SSA. Beijing also shows a reduction in ABS, while the SSA increase for Kanpur is mainly due the increase in scattering aerosols. Increased absorption and reduced SSA are found at Solar_Village. At level 1.5, most European and North American sites also show positive SSA and negative ABS trends, although the data are more uncertain. The AAE trends are less spatially coherent due to large uncertainties, except for a robust increase at three sites in West Africa, which suggests a possible reduction in black carbon. Overall, the trends do not exhibit obvious seasonality for the majority of parameters and stations.
Summary Background Percutaneous coronary intervention (PCI) is most commonly guided by angiography alone. Intravascular ultrasound (IVUS) guidance has been shown to reduce major adverse ...cardiovascular events (MACE) after PCI, principally by resulting in a larger postprocedure lumen than with angiographic guidance. Optical coherence tomography (OCT) provides higher resolution imaging than does IVUS, although findings from some studies suggest that it might lead to smaller luminal diameters after stent implantation. We sought to establish whether or not a novel OCT-based stent sizing strategy would result in a minimum stent area similar to or better than that achieved with IVUS guidance and better than that achieved with angiography guidance alone. Methods In this randomised controlled trial, we recruited patients aged 18 years or older undergoing PCI from 29 hospitals in eight countries. Eligible patients had one or more target lesions located in a native coronary artery with a visually estimated reference vessel diameter of 2·25–3·50 mm and a length of less than 40 mm. We excluded patients with left main or ostial right coronary artery stenoses, bypass graft stenoses, chronic total occlusions, planned two-stent bifurcations, and in-stent restenosis. Participants were randomly assigned (1:1:1; with use of an interactive web-based system in block sizes of three, stratified by site) to OCT guidance, IVUS guidance, or angiography-guided stent implantation. We did OCT-guided PCI using a specific protocol to establish stent length, diameter, and expansion according to reference segment external elastic lamina measurements. All patients underwent final OCT imaging (operators in the IVUS and angiography groups were masked to the OCT images). The primary efficacy endpoint was post-PCI minimum stent area, measured by OCT at a masked independent core laboratory at completion of enrolment, in all randomly allocated participants who had primary outcome data. The primary safety endpoint was procedural MACE. We tested non-inferiority of OCT guidance to IVUS guidance (with a non-inferiority margin of 1·0 mm2 ), superiority of OCT guidance to angiography guidance, and superiority of OCT guidance to IVUS guidance, in a hierarchical manner. This trial is registered with ClinicalTrials.gov , number NCT02471586. Findings Between May 13, 2015, and April 5, 2016, we randomly allocated 450 patients (158 35% to OCT, 146 32% to IVUS, and 146 32% to angiography), with 415 final OCT acquisitions analysed for the primary endpoint (140 34% in the OCT group, 135 33% in the IVUS group, and 140 34% in the angiography group). The final median minimum stent area was 5·79 mm2 (IQR 4·54–7·34) with OCT guidance, 5·89 mm2 (4·67–7·80) with IVUS guidance, and 5·49 mm2 (4·39–6·59) with angiography guidance. OCT guidance was non-inferior to IVUS guidance (one-sided 97·5% lower CI −0·70 mm2 ; p=0·001), but not superior (p=0·42). OCT guidance was also not superior to angiography guidance (p=0·12). We noted procedural MACE in four (3%) of 158 patients in the OCT group, one (1%) of 146 in the IVUS group, and one (1%) of 146 in the angiography group (OCT vs IVUS p=0·37; OCT vs angiography p=0·37). Interpretation OCT-guided PCI using a specific reference segment external elastic lamina-based stent optimisation strategy was safe and resulted in similar minimum stent area to that of IVUS-guided PCI. These data warrant a large-scale randomised trial to establish whether or not OCT guidance results in superior clinical outcomes to angiography guidance. Funding St Jude Medical.
Modern theoretical descriptions of inelastic scattering make use of multi-step direct reaction approaches together with transition potentials obtained from sophisticated nuclear structure models. ...Here we demonstrate how the complexity of such calculations can be reduced to permit simpler ones, also using the ECIS code, but providing an almost equally precise alternative to a much more detailed calculation. We have studied the transition form factors within the random phase approximation (RPA), where these are obtained as linear combinations of particle–hole states. At moderate to high excitation energies, where interference effects tend to disappear, we have proposed an independent particle–hole formalism in which particle–hole states are spread in energy with an appropriate strength function obtained from the RPA. The effects of more complex modes, such as 2p–2h ones, are simulated with widths calculated in a semi-classical context. Here, we verify the validity of our approximations for pre-equilibrium proton-induced reactions on
90
Zr target. Our calculations provide a good description of the reaction data and point toward a simplification of the description of nucleon-induced reactions based on averages of microscopic details of the projectile–target interaction.
Abstract
In the context of nuclear scattering, we use the bipolar reduction of the Schrödinger equation to examine the effects of optical model absorption on incoming and outgoing scattering waves. ...We compare the exact solutions for these waves, obtained using a bipolar quantum trajectory-based formalism, with their approximate WKB counterparts. Aside from reducing the magnitudes of the incoming and outgoing waves, absorption smooths the variation of the potential at the turning point, reducing reflection in this region. This brings the incoming exact solution and WKB approximation into closer agreement, but tends to worsen the agreement between the outgoing solutions. Inside the turning point, the WKB approximation overestimates the inward decaying solution. The exact solution also possesses an outward going component, solely due to reflection, with no WKB counterpart.
The relationship between a reported history of trauma and dissociative symptoms has been explained in 2 conflicting ways. Pathological dissociation has been conceptualized as a response to antecedent ...traumatic stress and/or severe psychological adversity. Others have proposed that dissociation makes individuals prone to fantasy, thereby engendering confabulated memories of trauma. We examine data related to a series of 8 contrasting predictions based on the trauma model and the fantasy model of dissociation. In keeping with the trauma model, the relationship between trauma and dissociation was consistent and moderate in strength, and remained significant when objective measures of trauma were used. Dissociation was temporally related to trauma and trauma treatment, and was predictive of trauma history when fantasy proneness was controlled. Dissociation was not reliably associated with suggestibility, nor was there evidence for the fantasy model prediction of greater inaccuracy of recovered memory. Instead, dissociation was positively related to a history of trauma memory recovery and negatively related to the more general measures of narrative cohesion. Research also supports the trauma theory of dissociation as a regulatory response to fear or other extreme emotion with measurable biological correlates. We conclude, on the basis of evidence related to these 8 predictions, that there is strong empirical support for the hypothesis that trauma causes dissociation, and that dissociation remains related to trauma history when fantasy proneness is controlled. We find little support for the hypothesis that the dissociation-trauma relationship is due to fantasy proneness or confabulated memories of trauma.
For readers, a properly conducted meta-analysis with a structured and transparent approach can provide multiple benefits over other literature reviews, such as reduced bias, enhanced ...generalizability, increased statistical power, and overall providing efficient knowledge dissemination, and informing design of future research 1,5. Evaluate methods used for citation screening and data extraction The methods section of a systematic review and meta-analysis detail the steps to systematically include and exclude studies and can help readers assess their quality. Readers should check that this dual data extraction process was completed because having only 1 person extract data for each study, as opposed to 2 people, has been shown to lead to more errors in the results, and these mistakes in collecting data could impact the effect estimates in the overall meta-analysis 15. ...review the results of that quality assessment, study by study and point by point, to determine the risk for inherited limitations or biases in each study included in the review.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
PDF
