R&D on the Resistive Plate Chamber for the Phase-II Upgrade of the CMS Muon Detector

The Doctoral Thesis subject has been proposed by the CMS RPC Collaboration to demonstrate that iRPC technology is the most suitable choice for the upgrade of the Muon System. The next research activities have been conducted in this context: The first activity, conducted in the framework of the iRPC RE3/1 and RE4/1 chambers integration and installation in the innermost region of CMS Muon Spectrometer, is focused on survey measurements performed in order to determine the space actually available for future installations during the Yearly Technical Stops at the end of 2022 and 2023. Surface topology and geometry of the Yoke Endcap (YE) ±2 and YE±3 iron disks in the region 1.8<|eta|<2.4 have been studied in detail by using different methods such as photography, photogrammetry, theodolite and infrared proximity sensor. After analyzing the experimental data obtained during the survey measurements, I developed the very precise 3D-model of the mechanical simulation for the installation of the RE3/1 and RE4/1 detectors in the dedicated |eta| region. I designed the mechanical components to mount chambers here. These results of my work were reported in the CMS Muon Technical Design Report (TDR) which was submitted to the CMS Muon Committee on 12 September 2017. The second activity has been focused on the developing, commissioning and characterization of the iRPC RE3/1 and RE4/1 detector prototypes. By using the information obtained during the previous activity, in August 2017 at the CERN CMS-RPC QA/QC facility, I organized the development and assembly of the first two real-size RE3/1 and RE4/1 detector prototypes and studied their detection performance with the new version of the PETIROC ASIC Front-end electronics. I was the key person who participated in all production processes on the construction and testing the detecting elements, assembling of the new prototypes and subsequent testing them with the new electronics under muon beam at the CERN Gamma Irradiation Facility (GIF++) in August 2018. By using the unique test area of the CERN GIF++ facility, I studied the iRPC detector performances at the different background conditions which will be similar to the future CMS conditions during the HL-LHC program. By studying the rate capability of the real-size iRPC detector prototypes I have experimentally shown that the new iRPC technology can effectively operate in the harsh background CMS environmental and can fulfill all physics requirements of the CMS experiment. The third my activity included the testing of the new INFN Rome Front-end electronics together with iRPC detector prototype. The INFN Rome electronics has been proposed as a possible alternative to PETIROC ASIC electronics in time for the CMS-RPC system upgrade project, thus increasing the chance of success for the project. This has been the main strategy adopted by the CMS-RPC community and, consequently, it was necessary to find another available technology in order to develop the Front-end electronics to readout the iRPC detectors. In September 2018, I developed and assembled the second real-size iRPC RE4/1 detector prototype in the INFN Rome Tor Vergata laboratories (Italy) in order to study the performance with the INFN Rome Front-end boards. As in the previous research activity, I organized the subsequent testing of the iRPC detector prototype with the new electronics in the last available muon particle beam in the GIF++ facility at CERN before the starting of the Long Shutdown -2 period at LHC. In order to compare the results obtained from the first two RE3/1 and RE4/1 detector prototypes, I have studied the same number of chamber parameters of second iRPC RE4/1 detector prototype, such as a detection efficiency, cluster size, and rate capability. I experimental shown that this type of new Front-end board can be a great substitute for the PETIROC ASIC electronics. A majority of the results obtained during the last two years of Ph.D. contributed to the success of the iRPC project and its final approval by CMS Collaboration

Distance Learning Experience in the Context of Globalization of Education

Today, the digitalization of education is one of the main tasks of the state social policy and an urgent sphere of life in modern society. At the beginning of 2020, the spread of COVID-19 forced educational institutions to introduce urgently all levels of distance learning technologies focused on the possibility to learn remotely and in real-time. The research focuses on the need to create an effective mechanism for organizing distance learning in the context of the globalization of education. The purpose of the research is to reveal the experience of distance learning in the context of globalization of education (based on the analysis of using the online learning platform Moodle). The results of the research reveal the prerequisites for the popularization of distance learning technologies in the practice of educational institutions, present the experience of using Moodle in the university educational process and determine the prospects of distance learning in educational practice

A growing concern for meaning: Exploring the links between ego development and eudaimonia

IntroductionEudaimonia, in contrast to hedonia, is theorized to be a more complex type of positive functioning that involves personal growth and is guided by the pursuit of meaning. However, the existing evidence linking eudaimonia to personality development is rather scarce. To fill this gap, we aimed to explore whether ego development is related to eudaimonic well-being and eudaimonic orientations, most notably, the concern for meaning: we explored both the quantitative differences in the presence of meaning and the search for it, as well as qualitative differences in lay theories of meaning.MethodsRussian-speaking volunteers recruited online (N = 364, aged 18 to 85, 63% female) completed measures of ego development (Washington University Sentence Completion Test), meaning in life (Meaning in Life Questionnaire), lay theories of meaning (and original 20-item measure), hedonic and eudaimonic motives for activities (HEMA), and well-being (Mental Health Continuum—Short Form).ResultsEgo development emerged as a weak, but significant positive predictor of well-being and this effect was fully mediated by the presence of meaning and eudaimonic motives. Latent profile analysis of the items tapping into lay theories of meaning revealed four distinct individual approaches to meaning that mainly differed in the subjective importance and salience of meaning. Participants with stronger concern for meaning revealed higher scores on ego development, both presence and search for meaning, eudaimonic motives, and well-being.DiscussionThe results add to the evidence concerning the links between ego development and well-being and are in line with the theoretical view of eudaimonia as a process of growth guided by personal concern for meaning. The findings suggest that eudaimonia might be more easily attained by individuals at higher stages of personal development

Performance of small-diameter muon drift tube chambers with new fast readout ASIC at high background rates

Experiments like ATLAS at the HL-LHC or detectors at future hadron colliders need muon detectors with excellent momentum resolution up to the TeV scale both at the trigger and offline reconstruction levels. This requires muon tracking chambers with high spatial resolution even at the highest background fluxes. Drift-tube chambers are the most cost-effective technology for large-area muon systems, providing the required high rate capability and three-dimensional spatial resolution. Thanks to advances in electronics, the new generation small-diameter Muon Drift Tube (sMDT) detectors with 15 mm tube diameter can be used in stand-alone mode up to the background rates expected at future hadron collider experiments, providing event times and second coordinates without additional trigger chambers. New developments in integrated front-end electronics include fast baseline restoration of the shaped signal and picosecond time-to-digital converters for second coordinate measurement with double-sided read-out. Self-triggered operation is now possible using modern high-performance FPGAs for real-time pattern recognition and track reconstruction. A new amplifier shaper discriminator chip in 65 nm TSMC CMOS technology with increased sensitivity and faster baseline recovery has been developed to cope with high background fluxes. Extensive test beam campaigns using sMDT chambers with new readout electronics have been performed at the CERN Gamma Irradiation Facility (GIF++). Results show that the shorter peaking time of the new chip enhances the spatial resolution of the drift tubes by up to 100 $μ$m at a background rate of 1 MHz, the maximum rate expected at the 100 TeV collider experiment.Contribution to the 16th Pisa Meeting ( May 26, 2024 to June 1, 2024 La Biodola - Isola d\u27Elba (Italy)) submitted to publish in a special issue of Nuclear Instruments and Methods in Physics Research

Search for top squark pair production using dilepton final states in pp collision data collected at root s=13TeV

A search is presented for supersymmetric partners of the top quark (top squarks) in final states with two oppositely charged leptons (electrons or muons), jets identified as originating from bquarks, and missing transverse momentum. The search uses data from proton-proton collisions at root s = 13 TeV collected with the CMS detector, corresponding to an integrated luminosity of 137 fb(-1). Hypothetical signal events are efficiently separated from the dominant top quark pair production background with requirements on the significance of the missing transverse momentum and on transverse mass variables. No significant deviation is observed from the expected background. Exclusion limits are set in the context of simplified supersymmetric models with pair-produced lightest top squarks. For top squarks decaying exclusively to a top quark and a lightest neutralino, lower limits are placed at 95% confidence level on the masses of the top squark and the neutralino up to 925 and 450 GeV, respectively. If the decay proceeds via an intermediate chargino, the corresponding lower limits on the mass of the lightest top squark are set up to 850 GeV for neutralino masses below 420 GeV. For top squarks undergoing a cascade decay through charginos and sleptons, the mass limits reach up to 1.4 TeV and 900 GeV respectively for the top squark and the lightest neutralino.Peer reviewe

Development and validation of HERWIG 7 tunes from CMS underlying-event measurements

This paper presents new sets of parameters (“tunes”) for the underlying-event model of the HERWIG7 event generator. These parameters control the description of multiple-parton interactions (MPI) and colour reconnection in HERWIG7, and are obtained from a fit to minimum-bias data collected by the CMS experiment at s=0.9, 7, and 13Te. The tunes are based on the NNPDF 3.1 next-to-next-to-leading-order parton distribution function (PDF) set for the parton shower, and either a leading-order or next-to-next-to-leading-order PDF set for the simulation of MPI and the beam remnants. Predictions utilizing the tunes are produced for event shape observables in electron-positron collisions, and for minimum-bias, inclusive jet, top quark pair, and Z and W boson events in proton-proton collisions, and are compared with data. Each of the new tunes describes the data at a reasonable level, and the tunes using a leading-order PDF for the simulation of MPI provide the best description of the dat

Measurement of the t(t)over-barb(b)over-bar production cross section in the all-jet final state in pp collisions at root s=13 TeV

A measurement of the production cross section of top quark pairs in association with two b jets (t (t) over barb (b) over bar) is presented using data collected in proton-proton collisions at root s=13 TeV by the CMS detector at the LHC corresponding to an integrated luminosity of 35.9 fb(-1). The cross section is measured in the all-jet decay channel of the top quark pair by selecting events containing at least eight jets, of which at least two are identified as originating from the hadronization of b quarks. A combination of multivariate analysis techniques is used to reduce the large background from multijet events not containing a top quark pair, and to help discriminate between jets originating from top quark decays and other additional jets. The cross section is determined for the total phase space to be 5.5 +/- 0.3 (stat)(-1.3)(+)(1.6) (syst)pb and also measured for two fiducial t (t) over barb (b) over bar, definitions. The measured cross sections are found to be larger than theoretical predictions by a factor of 1.5-2.4, corresponding to 1-2 standard deviations. (C) 2020 The Author. Published by Elsevier B.V.Peer reviewe

Search for dark matter in events with a leptoquark and missing transverse momentum in proton-proton collisions at 13 TeV

A search is presented for dark matter in proton-proton collisions at a center-of-mass energy of root s= 13 TeV using events with at least one high transverse momentum (p(T)) muon, at least one high-p(T) jet, and large missing transverse momentum. The data were collected with the CMS detector at the CERN LHC in 2016 and 2017, and correspond to an integrated luminosity of 77.4 fb(-1). In the examined scenario, a pair of scalar leptoquarks is assumed to be produced. One leptoquark decays to a muon and a jet while the other decays to dark matter and low-p(T) standard model particles. The signature for signal events would be significant missing transverse momentum from the dark matter in conjunction with a peak at the leptoquark mass in the invariant mass distribution of the highest p(T) muon and jet. The data are observed to be consistent with the background predicted by the standard model. For the first benchmark scenario considered, dark matter masses up to 500 GeV are excluded for leptoquark masses m(LQ) approximate to 1400 GeV, and up to 300 GeV for m(LQ) approximate to 1500 GeV. For the second benchmark scenario, dark matter masses up to 600 GeV are excluded for m(LQ) approximate to 1400 GeV. (C) 2019 The Author(s). Published by Elsevier B.V.Peer reviewe

Search for supersymmetry in final states with photons and missing transverse momentum in proton-proton collisions at 13 TeV

Results are reported of a search for supersymmetry in final states with photons and missing transverse momentum in proton-proton collisions at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb collected at a center-of-mass energy of 13 TeV using the CMS detector. The results are interpreted in the context of models of gauge-mediated supersymmetry breaking. Production cross section limits are set on gluino and squark pair production in this framework. Gluino masses below 1.86 TeV and squark masses below 1.59 TeV are excluded at 95% confidence levelIndividuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract No. 675440 (European Union); the Leventis Foundation; the A.P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation a la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F.R.S.-FNRS and FWO (Belgium) under the “Excellence of Science — EOS” — be.h project n. 30820817; the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Lendület (“Momentum”) Program and the J´anos Bolyai Research Scholarship of the Hungarian Academy of Sciences, the New National Excellence Program UNKP, the NKFIA research grants 123842, 123959, 124845, 124850 and 125105 (Hungary); the Council of Science and Industrial Research, India; the HOMING PLUS program of the Foundation for Polish Science, cofinanced from European Union, Regional Development Fund, the Mobility Plus program of the Ministry of Science and Higher Education, the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/02861, Sonata-bis 2012/07/E/ST2/01406; the National Priorities Research Program by Qatar National Research Fund; the Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias; the Thalis and Aristeia programs cofinanced by EU-ESF and the Greek NSRF; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); the Welch Foundation, contract C-1845; and the Weston Havens Foundation (U.S.A.)