Holographic description of elastic photon-proton and photon-photon scattering

We investigate the elastic photon-proton and photon-photon scattering in a holographic QCD model, focusing on the Regge regime. Considering contributions of the Pomeron and Reggeon exchange, the total and differential cross sections are calculated. While our model involves several parameters, by virtue of the universality of the Pomeron and Reggeon, for most of them the values determined in the preceding study on the proton-proton and proton-antiproton scattering can be employed. Once the two adjustable parameters, the Pomeron-photon and Reggeon-photon coupling constant, are determined with the experimental data of the total cross sections, predicting the both cross sections in a wide kinematic region, from the GeV to TeV scale, becomes possible. We show that the total cross section data can be well described within the model, and our predictions for the photon-proton differential cross section are consistent with the data.Comment: 13 pages, 3 figure

Upper secondary school youth' s mental health during the covid-19 pandemic : A qualitative study on the impact of the pandemic on upper secondary school youth' s mental health based on the experiences of school counselors

Syftet med den här studien är att utifrån skolkurators upplevelser om situationen för eleverna söka förståelse för vilken påverkan covid-19 pandemin har haft på gymnasieungdomars psykiska hälsa. I den här studien har det använts kvalitativa intervjuer för att undersöka och besvara studiens syfte och frågeställningar. Det har intervjuats fyra skolkuratorer som var verksamma i två olika gymnasieskolor i en kommun och som har arbetat under covid-19 pandemin. För analys av intervjuerna har systemteori använts. Resultatet visade att gymnasieungdomarna hade svårt att upprätthålla rutiner, de hade mindre sociala kontakter och spenderade mer tid i sitt rum. Skolmiljön innebär en rutin för ungdomar men vid distansundervisning blev deras vardag begränsad. Resultatet visade även att skolfrånvaron ökat och att studieresultatet blev sämre. Till följd av pandemin har ungdomarna känt social isolering och mer ensamhet vilket har haft påverkan på deras psykiska hälsa. Skolkuratorerna erbjöd elever både fysiskt och digitala samtal och informerade om andra stödlinjer utanför skolan som elever kan ta kontakt med för deras psykiska ohälsa. Elevsamtalen blev betydligt mindre nämnde tre av intervjupersonerna och för en av de blev det ingen skillnad. Det var även svårt för skolkuratorer att ge stöd digitalt eftersom de inte fick en bra relation eller kontakt till eleverna. Slutsatsen i denna uppsats är att restriktioner i samhället och distansstudier överlag har haft en negativ inverkan på gymnasieungdomars psykiska hälsa. Oro över skolgången, stress, ångest, svårt att upprätthålla rutiner, ensamhet, social isolering och sämre studieresultat framträder som förstärkande orsaker till psykisk ohälsa.

Holographic description of elastic photon-proton and photon-photon scattering

We investigate the elastic photon-proton and photon-photon scattering in a holographic QCD model, focusing on the Regge regime. Considering contributions of the Pomeron and Reggeon exchange, the total and differential cross sections are calculated. While our model involves several parameters, by virtue of the universality of the Pomeron and Reggeon, for most of them the values determined in the preceding study on the proton-proton and proton-antiproton scattering can be employed. Once the two adjustable parameters, the Pomeron-photon and Reggeon-photon coupling constant, are determined with the experimental data of the total cross sections, predicting the both cross sections in a wide kinematic region, from the GeV to TeV scale, becomes possible. We show that the total cross section data can be well described within the model, and our predictions for the photon-proton differential cross section are consistent with the data

Effects of Nitrogen Application on Growth and Yield of Groundnut (Arachis hypogaea L.) in Northeast Agro-Ecology of Afghanistan

A field experiment Conducted at the farm of Kunduz University during cropping season of 2023 to evaluate Effects of Nitrogen Application on Growth and Yield of Groundnut (Arachis hypogaea L.) in northeast of Afghanistan. The field experiment laid out in Randomized Complete Block Design with three replications, the treatments were Nitrogen fertilizer levels viz. Control, 15 kg N/ha, 30 kg N/ha and 45 kg N/ha respectively, result of the study revealed the highest Plant Height (32.61cm), Branches/plant (10.05), Leave area index (5.20), Kernel/pod (2.23), Pod weight (24.46), Pods/plant (32.30), 100- seed weight (76.38gr), Pod yield (2.89t/ha), haulm yield (5.53t/ha) and Biological yield (8.42t/ha) were in treatment with application 45 kg N/ha, the minimum growth and yield parameters were in Control plots, it can be concluded nitrogen fertilizer at the rate of 45 kg N/ha is optimum level for enhancing groundnut productivity and profitability in northeast of Afghanistan

Evaluation of Physical Activity Status among Yazd High School Students on the Model of the World Health Organization in 2015

Introduction: Physical activity and healthy eating at an early age are two key elements in prevention of Non-Communicable Diseases. Therefore, regular physical activity is recommended to improve public health and to reduce the burden of diseases and medical costs in communities. The aim of this study was to determine the status of physical activity in Yazd high school students Methods: A total number of1018 male high school students participated in this cross-sectional study. They were permanent residents of Yazd city in the school year of 2015-2016. Multistage cluster classification and stratified sampling methods were applied to collect samples. A validated Persian standardized World Health Organization questionnaire (GSHS) was used as a data collection tool. After completing the questionnaire by students, data were analyzed by SPSS. Results: only 11.6 % of participants reported physical activity for at least 60 minutes a day. Inert activities such as watching television or playing computer games for more than 2 hours during a typical day was reported by 531 participants (55 %). Based on body mass index, 18.23 % of students were obese and 13.22 % were overweight. Discussion and conclusion: The results of this study suggest that the level of students' physical activities is low. Paying more attention to physical activity and designing curriculums that devote more hours for physical activities are recommended. Encouraging physical activity in leisure time and providing proper facilities for adolescents are further suggestions