Мерење масе W бозона и калибрација импулса миона на детектору АТЛАС

U ovoj tezi je opisano meree mase W bozona, koje se zasniva na podacima prikup enim na detektoru ATLAS tokom 2011. godine u proton{proton sudarima na energiji od 7 TeV na Velikom sudaraqu hadrona (LHC). Prema Standardnom modelu masa W bozona zavisi od mase top kvarka i mase Higsovog bozona kroz korekcije vixeg reda. Preciznim mereem mase top kvarka, W i Higsovog bozona mogue je testirae konzistentnosti Standardnog modela, i bilo koje neslagae predstav a indirektan dokaz postojaa qestica izvan Standardnog modela. Masa W bozona je preth- odno izmerena na eksperimentima na Velikom eletron{pozitronskom su- daraqu, kao i na eksperimentima CDF i D0 na proton{antiproton su- daraqu Tevatron. Trenutna sreda vrednost izmerene mase W bozona iznosi mW = 80385 15 MeV, dok je najpreciznije meree ostvareno na eksperimentu CDF sa neodreenoxu 19 MeV. Sa druge strane, na osno- vu globalnog fita parametara Standardnog modela predviena masa W bozona iznosi mW = 80358 8 MeV...In this thesis measurement of the W-boson mass based on data collected during 2011 in proton–proton collisions at a centre-of-mass energy of 7 TeV with the ATLAS detector at the Large Hadron Collider (LHC) is presented. In the Standard Model, the Wboson mass depends on the top quark mass and the Higgs-boson mass through higher order corrections. Therefore, a precise measurements the mass of the top quark, Wand Higgs-boson, provide a stringent test of the Standard Model. Any observed inconsistency can be an indirect proof of the physics beyond the Standard Model. Previous measurements of the mass of the W boson are performed at the Large electron–positron collider, and at the Tevatron proton–antiproton collider with the CDF and D0 experiments. The current world average value of the W-boson mass is mW = 8038515 MeV, while the most precise single measurement with an uncertainty of 19 MeV is performed with the CDF experiment. On the other hand, the indirect constraint on the W-boson mass from the global electroweak fit predicts mW = 80358 8 MeV..

Социоекономските разлики помеѓу семејствата на деца со зголемена телесна тежина и дебелина во Северна Македонија

Globally, the prevalence of overweight and obesity is increasing among children and adolescents. Halting the rise in obesity is a significant challenge because of the complex interplay of factors and influences. We aimed to explore the role of family socioeconomic status (SES) indicators in relation to overweight and obesity prevalence rates among primary school children in North Macedonia. Materials and methods: Data were collected on a nationally representative sample of children and their parent(s)/caregiver(s) participating in the 6th round of World Health Organization (WHO)-European Childhood Obesity Surveillance Initiative (COSI) in North Macedonia. Every child had their height and weight objectively measured and their family sociodemographic and SES data were obtained through a self-reported record form by their parent(s)/caregiver(s). According to COSI reporting, responses on three SES indicators (parental educational attainment, parental employment status and family-perceived wealth) were categorized in levels for data analysis. Overweight and obesity rates were estimated based on 2007 WHO growth references. Pearson’s χ2-tests, corrected with the Rao-Scott method, were used to test differences in overweight and obesity across various subgroups. Results: The sample consisted of primarily native-born children (97.3%) and parents (mothers - 96.2%; fathers - 97.6%), living in urban areas (66.9%), in two-parent families (84.9%) and spoke Macedonian at home (59.8%). The majority of children lived in families with low to medium SES level. Prevalence of overweight was 30.5% [95% CI: 28.5-32.7], whilst of obesity 14.1% [95% CI: 12.3-16.0]. There were no significant differences observed across family SES indicators in overweight or obesity rates.  Conclusion: Our findings contribute towards reporting on family SES among children living with overweight and obesity to better understand and address potential obesity risk factors. Future research should focus on exploring family SES within the long-term context of children’s health-related behaviours.На глобално ниво, стапката на преваленција од зголемена телесна тежина и дебелина кај деца и адолесценти се зголемува. Запирањето на порастот на дебелината е значаен предизвик поради комплексната интеракција на многу фактори и влијанија. Цел на студијата беше да се истражи улогата на социоекономскиот статус (СЕС) на семејството во однос на преваленцијата на зголемена телесна тежина и дебелина кај децата, ученици во основните училишта во Северна Македонија.  Материјали и методи: Податоците беа собрани на национално репрезентативен примерок на деца и нивните родител(и)/старател(и), учесници во 6-от круг на СЗО - Европската иницијатива за следење на дебелината (COSI) во Северна Македонија. Телесната висина и тежина на секое дете беше објективно измерена, а социодемографските и СЕС податоци беа добиени од прашалникот за семејство пополнет од страна на нивните родител(и)/старател(и). Според претходни COSI публикации, одговорите за трите СЕС индикатори (степен на образование, работен статус и перцепции за економската благосостојба) беа категоризирани во нивоа за анализа на податоците. Стапките на зголемена телесна тежина и дебелина беа пресметани врз основа на СЗО референците за раст од 2007 година. Pearson-ов χ2-тест, коригиран со Rao-Scott методот, беа употребени за тестирање на разликите во стапките на зголемена телесна тежина и дебелина помеѓу различните подгрупи. Резултати: Примерокот за анализа се состоеше примарно од деца (97,3%) и родители мајка - 96,2%; татко - 97,6%) кои се родени во Македонија, живеат во урбани средини (66,9%), како двородителски семејства (84,9%), и зборуваат дома на македонски јазик (59,8%). Поголемиот број деца живееја во семејства со низок до среден социоекономски статус. Преваленцијата на зголемена телесна телесна тежина беше 30,5% [95% CI: 28.5-32.7], додека на дебелина 14,1% [95% CI: 12.3-16.0]. Не беа забележани значајни разлики помеѓу индикаторите на семејниот СЕС и превалентноста на зголемена телесна тежина и дебелина.  Заклучок: Нашите резултати придонесуваат кон евидентирање на социоекономскиот статус на семејството кај децата кои живеат со зголемена телесна тежина и дебелина со подобро разбирање и адресирање на потенцијалните ризик-фактори на дебелина. Идните истражувања треба да се фокусираат кон анализирање на семејниот СЕС во долгорочен контекст на поврзаноста со однесувањата поврзани со здравјето кај децата

Dose rate dependence of TID damage to 65 nm CMOS transistors in X-ray irradiations of the ATLAS ITk Pixel ASIC (ITkPix)

The ATLAS Inner Tracker (ITk) upgrade for the High-Luminosity LHC (HL-LHC) requires a radiation-tolerant pixel readout chip, which must withstand a total ionising dose (TID) of up to 1 Grad. The readout ASIC for the ITk upgrade has been designed by the RD53 collaboration using 65 nm CMOS technology. In order to characterise the radiation tolerance of the chip digital logic, the RD53 ASICs include ring oscillators, which can be used to measure gate delay degradation. Extensive X-ray irradiation studies of the ring oscillators have been performed on the ITk Pixel pre-production readout ASIC, ITkPixV1. A dependence of radiation damage on dose rate has been observed in 65 nm CMOS technology. This paper aims to quantify the dose rate dependence of TID damage to the ITkPix ring oscillators and, therefore, the ITkPix ASIC digital logic. X-ray irradiations at different dose rates between 20 krad/h and 30 Mrad/h are compared. A dose rate dependence is observed, with 2-3 times more damage at the lowest dose rate of 20 krad/h, compared to 4 Mrad/h. The dose rate dependence was also observed to be dependent on transistor size and type

Analysis, modeling, and simulation of emergency department

Overcrowding in the Emergency Department (ED) is one of the most important issues in healthcare systems. Two major causes of this congestion are identified, the first one is unjustified Emergency Department visits and the second one a lack of downstream beds. The lack of downstream beds can deteriorate the quality of care for patients who need hospitalization after an ED visit. In this paper a generic simulation model is developed in order to analyse patient pathways from the ED to hospital discharge

Level of natural radionuclides in animal feed by gamma –ray spectrometry

The radionuclides’ presence in animal feed is due both to natural radioactivity and radioactive pollution from different sources. Controls of radionuclides in animal feed will reduce the risk of radioactive hazards to animal and human health. The study was carried out in order to detect the natural radioactivity in animal feed and feed additive. Gamma spectrometer Canberra Packard with a high-purity germanium detector and Marinelli beakers (1 l capacity) were used for the samples measurement. The most prominent gamma energies observed in the spectra belonged to the naturally occurring radionuclides 40K, 226Ra and 232Th. Other radionuclides if present occurred infrequently at low activity concentration under the measurable level. The results show that 40K had the largest contribution to the specific radioactivity in all the samples. The mean activity concentration of the 40K was highest in feed additive mono calcium phosphate (245.03±17.778 Bq/kg) and lowest activity concentration of the 40K was measured in concentrate feed for dairy cows (23.20±2.626 Bq/kg). The average activity of the other two detected natural radionuclides in feed samples was lowest and ranged from 0.42 to 5.81 Bq/kg for 226Ra and from 0.61 to 2.55 Bq/kg for 232Th. The data analysis using ANOVA showed statistical significant differences in the radioactivity concentration of 40K, 226Ra and 232Th between feed samples (p<0.001). Key words: gamma spectrometry, feeds, natural radioactivity

Reconstruction of primary vertices at the ATLAS experiment in Run 1 proton–proton collisions at the LHC

This paper presents the method and performance of primary vertex reconstruction in proton–proton collision data recorded by the ATLAS experiment during Run 1 of the LHC. The studies presented focus on data taken during 2012 at a centre-of-mass energy of √s=8 TeV. The performance has been measured as a function of the number of interactions per bunch crossing over a wide range, from one to seventy. The measurement of the position and size of the luminous region and its use as a constraint to improve the primary vertex resolution are discussed. A longitudinal vertex position resolution of about 30μm is achieved for events with high multiplicity of reconstructed tracks. The transverse position resolution is better than 20μm and is dominated by the precision on the size of the luminous region. An analytical model is proposed to describe the primary vertex reconstruction efficiency as a function of the number of interactions per bunch crossing and of the longitudinal size of the luminous region. Agreement between the data and the predictions of this model is better than 3% up to seventy interactions per bunch crossing

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

Search for emerging jets in <i>pp</i> collisions at √<i>s</i> = 13.6 TeV with the ATLAS experiment

A search for emerging jets is presented using 51.8 fb-1 of proton-proton collision data at √s = 13.6 TeV, collected by the ATLAS experiment during 2022 and 2023. The search explores a hypothetical dark sector featuring 'dark quarks', which are charged under a confining gauge group and couple to the Standard Model via a new mediator particle. These dark quarks undergo showering and hadronization within the dark sector, forming long-lived dark mesons that decay back into Standard Model particles. This results in jets which contain multiple displaced vertices known as emerging jets. The analysis targets events with pairs of emerging jets, produced either through a vector mediator, Z', in the s-channel, or a scalar mediator, Φ, in the t-channel. No significant excess over the Standard Model background is observed. Assuming a dark pion proper decay length between 5 and 50 mm, Z′ mediator masses between 600 and 2550 GeV are excluded for quark and dark quark coupling values of 0.01 and 0.1, respectively. For a quark-dark quark coupling of 0.1, Φ mediator masses between 600 and 1375 GeV are excluded. These results provide the first direct constraints on emerging jet pair production via a Z' mediator, and represent the first search to investigate emerging jet production via t-channel exchange of a scalar mediator