2,098 research outputs found
Searches for Higgs bosons decaying to lepton pairs with the CMS detector
AbstractSearches for Higgs bosons decaying to lepton pairs are summarised using the run 1 dataset recorded by the CMS detector. The first part of this summary is devoted to the search for Higgs bosons decaying to tau pairs. The search is carried out using all six tau-pair final states, with the tau decaying to a muon, an electron, or hadrons. Evidence for Higgs boson decays to taus is reported, and constraints on the couplings of the Higgs boson to fermions and bosons are derived. Then, searches for Higgs boson decays to muons and electrons are also discussed. The last part discusses a search for lepton-flavour violating Higgs boson decays to a muon and a tau, with the tau being reconstructed in the decay to an electron or hadrons. The analysis places the best limits on the respective Yukawa couplings to date while showing a slight excess of 2.5 standard deviations above the standard model expectation
М. Ф. ФОН ДІТМАР – ЯСКРАВИЙПРЕДСТАВНИК ГІРНИЧОПРОМИСЛОВОЇ БУРЖУАЗІЇ ПІВДНЯ УКРАЇНИ(ОСТАННЯ ЧВЕРТЬ ХІХ– ПОЧАТОК ХХ СТ.)
В статті розглянуто постать відомого підприємця, науковця і суспільного діячаМ. Ф. фон
Дітмара, визначено основні напрями його діяльності наПівдні Українив останній чверті ХІХ
– на початку ХХ ст.The article considers the person of famous businessman, scientist and social activistM. F. von
Ditmar, determines themain directions of his activity in SouthernUkraine in the last quarter ofXIX –
the beginning ofXXcenturies
Bir gecelik çılgınlık
Asri Hafta'da tefrika edilen Bir Gecelik Çılgınlık adlı romanTefrikada yazarın adı belirtilmemiştir
Cyclooxygenase 2: understanding the pathophysiological role through genetically altered mouse models
El pdf del artículo es la versión post-print.Cyclooxygenase (COX) -1 and –2 catalyze the first step in the biosynthesis of prostanoids. COX-1 is constitutively expressed in many tissues and seems to be involved in the house keeping function of prostanoids. COX-2, the inducible isoform, accounts for the elevated production of prostaglandins in response to various inflammatory stimuli, hormones and growth factors. COX-2 expression has been also associated with cell growth regulation, tissue remodelling and carcinogenesis. More of these characteristics have been elucidate through using COX selective inhibitors. Recent advances in transgenic and gene-targeting approaches allow a sophisticated manipulation of the mouse genome by gene addition, gene deletion or gene modifications. The development of COX-2 genetically altered mice has provided models to elucidate the physiological and pathophysiological roles of this enzyme.This work was supported by grants from Instituto de Salud Carlos III (Red de Centros C03/01), Generalitat Valenciana (GRUPOS03/072), Ministerio de Educación y Ciencia (SAF2004-00957) and Comunidad de Madrid (CAM2004-GR/SAL/0388).Peer reviewe
A field study of data analysis exercises in a bachelor physics course using the internet platform VISPA
Bachelor physics lectures on particle physics and astrophysics were
complemented by exercises related to data analysis and data interpretation at
the RWTH Aachen University recently. The students performed these exercises
using the internet platform VISPA, which provides a development environment for
physics data analyses. We describe the platform and its application within the
physics course, and present the results of a student survey. The students
acceptance of the learning project was positive. The level of acceptance was
related to their individual preference for learning with a computer.
Furthermore, students with good programming skills favor working individually,
while students who attribute themselves having low programming abilities favor
working in teams. The students appreciated approaching actual research through
the data analysis tasks.Comment: 21 pages, 8 figures, 1 table, for the internet platform VISPA see
http://vispa.physik.rwth-aachen.d
Формирование профилированных импульсов напряжения для время пролетного спектрометра
В работе рассматривается возможность создания время пролетного спектрометра (ВПР) с высокой разрешающей способностью. Работа прибора основана на использовании временной группировки ионов с монотонно растущей энергией, задаваемой в анализирующим элементе ВПР спектрометра. Основная задача получения профилированных импульсов ускоряющего ионы напряжения решается с использованием оригинального формирователя, с включенной параллельно нагрузке предварительно заряженной емкости задающей уровень коррекции напряжения. Проведено моделирование различных модификаций генераторов импульсов. Разработан формирователь с частичным разрядом накопительной емкости и полупроводниковым коммутаторомThe paper considers the possibility of creating a time-of-flight spectrometer with high resolution. The operation of the device is based on the use of a time grouping of ions with a monotonically increasing energy, set in the analyzing element of the spectrometer. The main task of obtaining profiled pulses of ion-accelerating voltage is solved using an original shaper, with a pre-charged capacitance connected in parallel to the load, which sets the level of voltage correction. Various modifications of pulse generators are modeled. A shaper with a partial discharge of the storage capacity and a semiconductor switch has been develope
Particle-flow reconstruction and global event description with the CMS detector
The CMS apparatus was identified, a few years before the start of the LHC operation at CERN, to feature properties well suited to particle-flow (PF) reconstruction: a highly-segmented tracker, a fine-grained electromagnetic calorimeter, a hermetic hadron calorimeter, a strong magnetic field, and an excellent muon spectrometer. A fully-fledged PF reconstruction algorithm tuned to the CMS detector was therefore developed and has been consistently used in physics analyses for the first time at a hadron collider. For each collision, the comprehensive list of final-state particles identified and reconstructed by the algorithm provides a global event description that leads to unprecedented CMS performance for jet and hadronic tau decay reconstruction, missing transverse momentum determination, and electron and muon identification. This approach also allows particles from pileup interactions to be identified and enables efficient pileup mitigation methods. The data collected by CMS at a centre-of-mass energy of 8 TeV show excellent agreement with the simulation and confirm the superior PF performance at least up to an average of 20 pileup interactions
Identification of heavy-flavour jets with the CMS detector in pp collisions at 13 TeV
Many measurements and searches for physics beyond the standard model at the LHC rely on the efficient identification of heavy-flavour jets, i.e. jets originating from bottom or charm quarks. In this paper, the discriminating variables and the algorithms used for heavy-flavour jet identification during the first years of operation of the CMS experiment in proton-proton collisions at a centre-of-mass energy of 13 TeV, are presented. Heavy-flavour jet identification algorithms have been improved compared to those used previously at centre-of-mass energies of 7 and 8 TeV. For jets with transverse momenta in the range expected in simulated events, these new developments result in an efficiency of 68% for the correct identification of a b jet for a probability of 1% of misidentifying a light-flavour jet. The improvement in relative efficiency at this misidentification probability is about 15%, compared to previous CMS algorithms. In addition, for the first time algorithms have been developed to identify jets containing two b hadrons in Lorentz-boosted event topologies, as well as to tag c jets. The large data sample recorded in 2016 at a centre-of-mass energy of 13 TeV has also allowed the development of new methods to measure the efficiency and misidentification probability of heavy-flavour jet identification algorithms. The heavy-flavour jet identification efficiency is measured with a precision of a few per cent at moderate jet transverse momenta (between 30 and 300 GeV) and about 5% at the highest jet transverse momenta (between 500 and 1000 GeV)
Search for heavy resonances decaying to a top quark and a bottom quark in the lepton+jets final state in proton–proton collisions at 13 TeV
info:eu-repo/semantics/publishe
Evidence for the Higgs boson decay to a bottom quark–antiquark pair
info:eu-repo/semantics/publishe
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