1,836 research outputs found
Pion correlation from Skyrmion-AntiSkyrmion annihilation
We study two pion correlations from Skyrmion and antiSkyrmion collision,
using the product ansatz and an approximate random grooming method for nucleon
projection. The spatial-isospin coupling inherent in the Skyrme model, along
with empirical averages, leads to correlations not only among pions of like
charges but also among unlike charge types.Comment: uuencoded files of REVTeX and postscript, 18 pages including 2
figures, submitted to Phys.Rev.
Application of the FANTASTIC Lifestyle Questionnaire in the Academic Context
Studying citizensâ lifestyles is extremely important for understanding society and the social conditions of the personal lifestyle. Understanding the lifestyles of university students is especially important because they will be the future citizens and professionals who will shape societyâs future. The aim of this study was a systematic review of the scientific literature about the use of the FANTASTIC Lifestyle questionnaire in an academic context. The reflective systematic literature review was carried out on PubMed, MEDLINE, Science Direct, and SCIELO databases with the keywords (âFANTASTIC Lifestyle questionnaireâ OR âFANTASTICO questionnaireâ OR âFANTASTIC questionnaireâ OR âFANTASTIC surveyâ OR âFANTASTIC checklistâ) AND (âuniversity studentsâ). The PRISMA criteria for reporting systematic reviews and meta-analyses were applied. The inclusion criteria were the use of the âFANTASTIC Lifestyle questionnaireâ instrument for measuring lifestyles, the presentation of quantitative or qualitative results, and psychometric studies. The exclusion criteria were no use of FANTASTIC Lifestyle Questionnaire; other population, no quantitative or qualitative analysis, incomplete articles. The 15 scientific articles included in the study were analyzed. This literature review allowed us to conclude the importance and usefulness/actuality of this questionnaire. Furthermore, the importance of diagnosis should be emphasized, as should the development of strategies and intervention programs for the maintenance or creation of healthy societies
On the relationship of the scaled phase space and Skyrme-coherent state treatments of proton antiproton annihilation at rest
We discuss pion multiplicities and single pion momentum spectra from proton
antiproton annihilation at rest. Both the scaled phase space model and the
Skyrme-coherent state approach describe these observables well. In the coherent
state approach the puzzling size of the scale parameter relating the phase
space integrals for different multiplicities is replaced by a well defined
weight function. The strength of this function is determined by the intensity
of the classical pion field and its spatial extent is of order 1 fm.Comment: 11 pages including 4 figures(postscript
Effective core potential ab initio calculations on main group heptoxides and large silicate systems
The ab initio molecular structures for several main group heptoxides (X2O7n-, n=0,2,4) are calculated using effective core potentials at the HF and DFT (B3LYP) levels. Particular attention is given to the X-O-X bond angle, as this structural parameter is a key feature for the study of both heptoxides and larger derivatives, such as polysilicate systems. The extent of the p-d interactions, which was found to be the main factor governing the magnitude of the X-O-X angle in transition metal heptoxides, does not play a significant role in the main group analogues.http://www.sciencedirect.com/science/article/B6TGT-40V4F3D-3/1/f26d56c6395122fcba007ed20f55868
High-cadence spectroscopy of M-dwarfs â II. Searching for stellar pulsations with HARPS
Stellar oscillations appear all across the HertzsprungâRussell diagram. Recent theoretical studies support their existence also in the atmosphere of M dwarfs. These studies predict for them short periodicities ranging from 20 min to 3 h. Our Cool Tiny Beats (CTB) programme aims at finding these oscillations for the very first time. With this goal, CTB explores the short time domain of M dwarfs using radial velocity data from the High Accuracy Radial velocity Planet Searcher (HARPS)-European Southern Observatory and HARPS-N high-precision spectrographs. Here we present the results for the two most long-term stable targets observed to date with CTB, GJ 588 and GJ 699 (i.e. Barnard's star). In the first part of this work we detail the correction of several instrumental effects. These corrections are especially relevant when searching for subnight signals. Results show no significant signals in the range where M dwarfs pulsations were predicted. However, we estimate that stellar pulsations with amplitudes larger than âŒ0.5âmâsâ1 can be detected with a 90 per cent completeness with our observations. This result, along with the excess of power regions detected in the periodograms, opens the possibility of non-resolved very low amplitude pulsation signals. Next generation more precise instrumentation would be required to detect such oscillations. However, the possibility of detecting pulsating M-dwarf stars with larger amplitudes is feasible due to the short size of the analysed sample. This motivates the need for completeness of the CTB survey
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