1,631 research outputs found
Transverse momentum distribution of vector mesons produced in ultraperipheral relativistic heavy ion collisions
We study the transverse momentum distribution of vector mesons produced in
ultraperipheral relativistic heavy ion collisions (UPCs). In UPCs there is no
strong interaction between the nuclei and the vector mesons are produced in
photon-nucleus collisions where the (quasireal) photon is emitted from the
other nucleus. Exchanging the role of both ions leads to interference effects.
A detailed study of the transverse momentum distribution which is determined by
the transverse momentum of the emitted photon, the production process on the
target and the interference effect is done. We study the total unrestricted
cross section and those, where an additional electromagnetic excitation of one
or both of the ions takes place in addition to the vector meson production, in
the latter case small impact parameters are emphasized.Comment: 12 pages, REVTeX manuscrip
Cognitive Understanding of Reverse Engineering Assistant
The Cognitive Understanding of Reverse Engineering Assistant, or C.U.R.E. Assistant for short, is an independently developed program with the purpose of introducing students of the software reverse-engineering world to the art of disassembly. Reverse Engineering, or R.E. for short, is the process of deducing the source instructions or mechanisms of a device. This can be done to software to figure out how it works and how it can be exploited. While hackers employ this method for breaking into software systems, this is very useful for security researchers to determine security vulnerabilities in internet browsers, operating systems, apps, and more, so they can fix the problems before people using the software get exploited. Unfortunately, this is a very difficult and even expensive skill to learn, but C.U.R.E. Assistant seeks to mitigate that effort and cost. By analyzing a binary and then displaying the results in a user-friendly graphical interface, C.U.R.E. Assistant is able to point out areas of interest to those who may not know what to look for or where to start. In addition, it is designed with added functionality to ease users into learning the intricate, but popular, reverse-engineering tool, Radare2. Inspired by the massive learning curve and scant available training for software dissection, C.U.R.E. Assistant aims to both streamline the process for experienced engineers as well as educate those new to the field in a friendly and informative manner
Improved radiative corrections for (e,e'p) experiments - A novel approach to multi-photon bremsstrahlung
Radiative processes lead to important corrections to (e,e'p) experiments.
While radiative corrections can be calculated exactly in QED and to a good
accuracy also including hadronic corrections, these corrections cannot be
included into data analyses to arbitrary orders exactly. Nevertheless
consideration of multi-photon bremsstrahlung above the low-energy cut-off is
important for many (e,e'p) experiments. To date, higher-order bremsstrahlung
effects concerning electron scattering experiments have been implemented
approximately by employing the soft-photon approximation (SPA). In this paper
we propose a novel approach to multi-photon emission which partially removes
the SPA from (e,e'p) experiments. In this combined approach one hard photon is
treated exactly; and additional softer bremsstrahlung photons are taken into
account resorting to the soft-photon approximation. This partial removal of the
soft-photon approximation is shown to be relevant for the missing-energy
distribution for several kinematic settings at MAMI and TJNAF energies.Comment: 10 pages, 21 figure
Transition from participant to spectator fragmentation in Au+Au reaction between 60 AMeV and 150 AMeV
Using the quantum molecular dynamics approach, we analyze the results of the
recent INDRA Au+Au experiments at GSI in the energy range between 60 AMeV and
150 AMeV. It turns out that in this energy region the transition toward a
participant-spectator scenario takes place. The large Au+Au system displays in
the simulations as in the experiment simultaneously dynamical and statistical
behavior which we analyze in detail: The composition of fragments close to
midrapidity follows statistical laws and the system shows bi-modality, i.e. a
sudden transition between different fragmentation pattern as a function of the
centrality as expected for a phase transition. The fragment spectra at small
and large rapidities, on the other hand, are determined by dynamics and the
system as a whole does not come to equilibrium, an observation which is
confirmed by FOPI experiments for the same system.Comment: published versio
Prevalence and severity of mental disorders in military personnel: a standardised comparison with civilians
Aims. Provision and need for mental health services among military personnel are a major concern across nations. Two recent comparisons suggest higher rates of mental disorders in US and UK military personnel compared with civilians. However, these findings may not apply to other nations. Previous studies have focused on the overall effects of military service rather than the separate effects of military service and deployment. This study compared German military personnel with and without a history of deployment to sociodemographically matched civilians regarding prevalence and severity of 12-month DSM-IV mental disorders.
Method. 1439 deployed soldiers (DS), 779 never deployed soldiers (NS) and 1023 civilians were assessed with an adapted version of the Munich Composite International Diagnostic interview across the same timeframe. Data were weighted using propensity score methodology to assure comparability of the three samples.
Results. Compared with adjusted civilians, the prevalence of any 12-month disorder was lower in NS (OR: 0.7, 95% CI: 0.5â0.99) and did not differ in DS. Significant differences between military personnel and civilians regarding prevalence and severity of individual diagnoses were only apparent for alcohol (DS: OR: 0.3, 95% CI: 0.1â0.6; NS: OR: 0.2, 95% CI: 0.1â0.6) and nicotine dependence (DS: OR: 0.5, 95% CI: 0.3â0.6; NS: OR: 0.5, 95% CI: 0.3â0.7) with lower values in both military samples. Elevated rates of panic/agoraphobia (OR: 2.7, 95% CI: 1.4â5.3) and posttraumatic stress disorder (OR: 3.2, 95% CI: 1.3â8.0) were observed in DS with high combat exposure compared with civilians.
Conclusions. Rates and severity of mental disorders in the German military are comparable with civilians for internalising and lower for substance use disorders. A higher risk of some disorders is reduced to DS with high combat exposure. This finding has implications for mental health service provision and the need for targeted interventions. Differences to previous US and UK studies that suggest an overall higher prevalence in military personnel might result from divergent study methods, deployment characteristics, military structures and occupational factors. Some of these factors might yield valuable targets to improve military mental health
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