Note: When clicking on a Digital Object Identifier (DOI) number, you will be taken to an external site maintained by the publisher.
                                            Some full text articles may not yet be available without a charge during the embargo (administrative interval).
                                        
                                        
                                        
                                            
                                                
                                             What is a DOI Number?
                                        
                                    
                                
Some links on this page may take you to non-federal websites. Their policies may differ from this site.
- 
            High-resolution x-ray spectra were recorded at the National Institute of Standards and Technology electron beam ion trap (EBIT) using two Johann-type crystal spectrometers, with their dispersion planes oriented parallel and perpendicular to the beam direction. The linear polarizations of the 1s2−1s2l transitions in He-like argon ions were determined from the measured spectra at electron beam energies of 3.87 and 7.91 keV. The theoretical analysis was performed using detailed collisional-radiative modeling of the non-Maxwellian EBIT plasma with the NOMAD code modified to account for magnetic sublevel atomic kinetics. Effects influencing the polarizations of the observed 1s2−1s2l lines were investigated, including radiative cascades, the 1s2 1S0−1s2s 1S0 two-photon transition, and the charge exchange recombination of H-like argon ions. With these included, the measured polarizations of the resonance (1s2 1S0−1s2p 1P1), intercombination (1s2 1S0−1s2p 3P1), and forbidden lines (1s2 1S0−1s2s 3S1, 1s2 1S0−1s2p 3P2 ) were found to be in good agreement with the calculations.more » « less
- 
            This paper investigates the psychological traits of individuals’ attraction to engaging in hacking behaviors (both ethical and illegal/unethical)upon entering the workforce.We examine the role of the Dark Triad, Opposition to Authority and Thrill-Seeking traits as regards the propensity of an individual to be interested in White Hat, Black Hat,and Grey Hat hacking. A new set of scales were developed to assist in the delineation of the three hat categories. We also developed a scale to measure each subject’s perception of the probability of being apprehended for violating privacy laws. Engaging in criminal activity involves a choice where there are consequences and opportunities, and individuals perceive them differently, but they can be deterred if there is a likelihood of punishment,and the punishment is severe. The results suggest that individuals that are White Hat, Grey Hat and Black Hat hackers score high on the Machiavellian and Psychopathy scales. We also found evidence that Grey Hatters oppose authority, Black Hatters score high on the thrill-seeking dimension and White Hatters, the good guys, tend to be Narcissists. Thrill-seeking was moderately important for White Hat hacking and Black hat hacking. Opposition to Authority was important for Grey Hat hacking. Narcissism was not statistically significant in any of the models. The probability of being apprehended had a negative effect on Grey Hat and Black Hat hacking. Several suggestions will be made on what organizations can do to address insider threats.more » « less
- 
            This paper investigates the psychological traits of individuals’ attraction to engaging in hacking behaviors (both ethical and illegal/unethical)upon entering the workforce.We examine the role of the Dark Triad, Opposition to Authority and Thrill-Seeking traits as regards the propensity of an individual to be interested in White Hat, Black Hat,and Grey Hat hacking. A new set of scales were developed to assist in the delineation of the three hat categories. We also developed a scale to measure each subject’s perception of the probability of being apprehended for violating privacy laws. Engaging in criminal activity involves a choice where there are consequences and opportunities, and individuals perceive them differently, but they can be deterred if there is a likelihood of punishment,and the punishment is severe. The results suggest that individuals that are White Hat, Grey Hat and Black Hat hackers score high on the Machiavellian and Psychopathy scales. We also found evidence that Grey Hatters oppose authority, Black Hatters score high on the thrill-seeking dimension and White Hatters, the good guys, tend to be Narcissists. Thrill-seeking was moderately important for White Hat hacking and Black hat hacking. Opposition to Authority was important for Grey Hat hacking. Narcissism was not statistically significant in any of the models. The probability of being apprehended had a negative effect on Grey Hat and Black Hat hacking. Several suggestions will be made on what organizations can do to address insider threats.more » « less
- 
            Abstract Accurate extreme ultraviolet spectra of open N -shell neodymium (Nd) ions were recorded at the electron beam ion trap facility of the National Institute of Standards and Technology. The measurements were performed for nominal electron beam energies in the range of 0.90 keV to 2.31 keV. The measured spectra were then compared with the spectra simulated by a collisional-radiative model utilizing atomic data produced with a fully relativistic atomic structure code. Consequently, 59 lines from Br-like to Ni-like Nd ions were unambiguously identified, most of which were newly assigned in this study. The wavelengths of 9 known lines from Ni-, Cu- and Zn-like Nd ions were in excellent agreement with previous measurements.more » « less
- 
            Abstract Despite the f0(980) hadron having been discovered half a century ago, the question about its quark content has not been settled: it might be an ordinary quark-antiquark ($${{\rm{q}}}\overline{{{\rm{q}}}}$$ ) meson, a tetraquark ($${{\rm{q}}}\overline{{{\rm{q}}}}{{\rm{q}}}\overline{{{\rm{q}}}}$$ ) exotic state, a kaon-antikaon ($${{\rm{K}}}\overline{{{\rm{K}}}}$$ ) molecule, or a quark-antiquark-gluon ($${{\rm{q}}}\overline{{{\rm{q}}}}{{\rm{g}}}$$ ) hybrid. This paper reports strong evidence that the f0(980) state is an ordinary$${{\rm{q}}}\overline{{{\rm{q}}}}$$ meson, inferred from the scaling of elliptic anisotropies (v2) with the number of constituent quarks (nq), as empirically established using conventional hadrons in relativistic heavy ion collisions. The f0(980) state is reconstructed via its dominant decay channel f0(980) →π+π−, in proton-lead collisions recorded by the CMS experiment at the LHC, and itsv2is measured as a function of transverse momentum (pT). It is found that thenq= 2 ($${{\rm{q}}}\overline{{{\rm{q}}}}$$ state) hypothesis is favored overnq= 4 ($${{\rm{q}}}\overline{{{\rm{q}}}}{{\rm{q}}}\overline{{{\rm{q}}}}$$ or$${{\rm{K}}}\overline{{{\rm{K}}}}$$ states) by 7.7, 6.3, or 3.1 standard deviations in thepT< 10, 8, or 6 GeV/cranges, respectively, and overnq= 3 ($${{\rm{q}}}\overline{{{\rm{q}}}}{{\rm{g}}}$$ hybrid state) by 3.5 standard deviations in thepT< 8 GeV/crange. This result represents the first determination of the quark content of the f0(980) state, made possible by using a novel approach, and paves the way for similar studies of other exotic hadron candidates.more » « lessFree, publicly-accessible full text available December 1, 2026
- 
            Free, publicly-accessible full text available September 1, 2026
- 
            Free, publicly-accessible full text available September 1, 2026
- 
            Free, publicly-accessible full text available September 1, 2026
 An official website of the United States government
An official website of the United States government 
				
			 
					 
					
 
                                     Full Text Available
                                                Full Text Available