2,171 research outputs found
STRUKTURA IZVLEČKOV S PODROČJA MATERIALOV IN TEHNOLOGIJ
No full textABSTRACTWe investigated the structure of abstracts in Slovenian and international journals in the field of materials and technology. The aim of the study was to analyze the adherence of the abstracts published in Materials and Technology (MIT) and Materials Science and Technology (MST) to two different instructions for the preparation of abstracts (scheme based on ISO 214:1976 and Spanring system). 25 abstracts from each journal were divided into sentences. We tried to place the sentences into one of the categories of the above mentioned schemes. The research was a part of the postgraduate study in the Department of Library and Information Science and Book Studies(Faculty of Arts, Ljubljana) in September and October 2008. There are no important differences between MIT and MST. Spanring system seems more appropriate for the field of materials and technology. The place and the time of the research should be added to abstracts and the Hu-bit category should be distributed into two parts: Hu-M (method) and Hu-R (results). The recommended Spanring system should be harmonized with authors, who publish in these serials and the effect of the instructions should be analyzed, too.IZVLEČEKZanimala nas je struktura izvlečkov slovenskih in tujih revij s področja materialov in tehnologij. Namen in cilj raziskave je bil preveriti ustreznost izvlečkov člankov, objavljenihv revijah Materiali in tehnologije (MIT) in Materials Science and Technology (MST), glede na dve različni vrsti navodil za pripravo izvlečkov (shema, zasnovana glede na standard ISO 214:1976, ter shema Spanringovih informemov). Petindvajset izvlečkov iz vsake revije je bilo razdeljenih na povedi, ki se jih je skušalo uvrstiti v eno izmed kategorij obeh shem. Raziskava je bila izvedena v okviru podiplomskega študija na Oddelku za bibliotekarstvo, informacijsko znanost in knjigarstvo Filozofske fakultete Univerze v Ljubljani in je potekala septembra in oktobra 2008. Ugotovljeno je bilo, da se za področje materialov in tehnologij zdijo Spanringovi informemi uporabnejši od strukture, ki jo priporoča standard ISO-214:1976, ter da ni pomembnejših razlik med revijama MIT in MST, niti glede na strukturno shemo ISO niti glede na Spanringove informeme. Avtorje bi bilo treba opozoriti, naj v svojem izvlečku opredelijo tudi kraj in čas raziskave ter razmislijo o razdelitvi informema Hu na dva dela: Hu-M (metoda) in Hu-R (rezultati). Priporočeno shemo Spanringovih informemov bi bilo potrebno uskladiti z avtorji, ki objavljajo v teh revijah, in nato preveriti učinek navodil
Search for a heavy composite Majorana neutrino in the final state with two leptons and two quarks at root s=13 TeV
No full textA search for physics beyond the standard model in the final state with two same-flavour leptons (electrons or muons) and two quarks produced in proton-proton collisions at root s = 13 TeVis presented. The data were recorded by the CMS experiment at the CERN LHC and correspond to an integrated luminosity of 2.3 fb(-1). The observed data are in good agreement with the standard model background prediction. The results of the measurement are interpreted in the framework of a recently proposed model in which a heavy Majorana neutrino, N-l, stems from a composite-fermion scenario. Exclusion limits are set for the first time on the mass of the heavy composite Majorana neutrino, m(Nl), and the compositeness scale Lambda. For the case m(Nl) = Lambda, the existence of N-e (N-mu) is excluded for masses up to 4.60 (4.70) TeV at 95% confidence level. (C) 2017 The Author(s). Published by Elsevier B.V
A measurement of the Higgs boson mass in the diphoton decay channel
No full textA measurement of the mass of the Higgs boson in the diphoton decay channel is presented. This analysis is based on 35.9 fb(-1) of proton-proton collision data collected during the 2016 LHC running period, with the CMS detector at a centre-of-mass energy of 13 TeV. A refined detector calibration and new analysis techniques have been used to improve the precision of this measurement. The Higgs boson mass is measured to be m(H) = 125.78 +/- 0.26GeV. This is combined with a measurement of m(H) already performed in the H -> ZZ -> 4l decay channel using the same data set, giving m(H) = 125.46 +/- 0.16GeV. This result, when further combined with an earlier measurement of m(H) using data collected in 2011 and 2012 with the CMS detector, gives a value for the Higgs boson mass of m(H) = 125.38 +/- 0.14GeV. This is currently the most precise measurement of the mass of the Higgs boson. (C) 2020 The Author(s). Published by Elsevier B.V
Search for long-lived particles using nonprompt jets and missing transverse momentum with proton-proton collisions at root s=13 TeV
No full textA search for long-lived particles decaying to displaced, nonprompt jets and missing transverse momentum is presented. The data sample corresponds to an integrated luminosity of 137 fb(-1) of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC in 2016-2018. Candidate signal events containing nonprompt jets are identified using the timing capabilities of the CMS electromagnetic calorimeter. The results of the search are consistent with the background prediction and are interpreted using a gauge-mediated supersymmetry breaking reference model with a gluino next-to-lightest supersymmetric particle. In this model, gluino masses up to 2100, 2500, and 1900 GeV are excluded at 95% confidence level for proper decay lengths of 0.3, 1, and 100 m, respectively. These are the best limits to date for such massive gluinos with proper decay lengths greater than similar to 0.5 m. (C) 2019 The Author. Published by Elsevier B.V
Search for dark matter in events with a leptoquark and missing transverse momentum in proton-proton collisions at 13 TeV
No full textA 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
Evidence for light-by-light scattering and searches for axion-like particles in ultraperipheral PbPb collisions at root s(NN)=5.02 TeV
No full textEvidence for the light-by-light scattering process, gamma gamma -> gamma gamma, in ultraperipheral PbPb collisions at a centre-of-mass energy per nucleon pair of 5.02 TeV is reported. The analysis is conducted using a data sample corresponding to an integrated luminosity of 390 mu b(-1) recorded by the CMS experiment at the LHC. Light-by-light scattering processes are selected in events with two photons exclusively produced, each with transverse energy E-T(gamma) > 2 GeV, pseudorapidity vertical bar eta(gamma)vertical bar < 2.4, diphoton invariant mass m(gamma gamma) > 5 GeV, diphoton transverse momentum p(T)(gamma gamma) < 1 GeV, and diphoton acoplanarity below 0.01. After all selection criteria are applied, 14 events are observed, compared to expectations of 9.0 +/- 0.9 (theo) events for the signal and 4.0 +/- 1.2 (stat) for the background processes. The excess observed in data relative to the background-only expectation corresponds to a significance of 3.7 standard deviations, and has properties consistent with those expected for the light-by-light scattering signal. The measured fiducial light-by-light scattering cross section, sigma(fid)(gamma gamma -> gamma gamma) = 120 +/- 46(stat) +/- 28(syst) +/- 12(theo) nb, is consistent with the standard model prediction. The m(gamma gamma) distribution is used to set new exclusion limits on the production of pseudoscalar axion-like particles, via the gamma gamma -> a -> gamma gamma process, in the mass range m(a) = 5-90 GeV. (C) 2019 The Author(s). Published by Elsevier B.V
Determination of the strong coupling constant alpha(S)(m(Z)) from measurements of inclusive W-+/- and Z boson production cross sections in proton-proton collisions at root s=7 and 8 TeV
No full textTwelve measurements of inclusive cross sections of W-+/- and Z boson production, performed in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, are compared with perturbative quantum chromodynamics calculations at next-to-next- to-leading order (NNLO) accuracy obtained with the CT14, HERAPDF2.0, MMHT14, and NNPDF3.0 parton distribution functions (PDFs). Data and theory agree well for all PDF sets, taking into account the experimental and theoretical uncertainties. A novel procedure is employed to extract the strong coupling constant at the Z pole mass from a detailed comparison of all the experimental fiducial cross sections to the corresponding NNLO theoretical predictions, yielding alpha S (m(Z)) = 0.1163(-0.0031)(+0.0024) (CT14), 0.1072(-0.0040)(+0.0043) (HERAPDF2.0), 0.1186 +/- 0. 0025 (MMHT14), and 0.1147 +/- 0.0023 (NNPDF3.0). Using the results obtained with the CT14 and MMHT14 PDFs, which yield the most robust and stable alpha(S)(mZ) extractions, a value alpha(S)(m(Z)) = 0.1175(-0.0028)(+0.0025) is determined
Search for new physics in dijet angular distributions using proton-proton collisions at root s = 13TeV and constraints on dark matter and other models (vol 78, 789, 2018)
No full textIn this article the author name Luigi Calligaris was incorrectly written as A. Calligaris. The original article has been corrected
Measurement of exclusive Upsilon photoproduction from protons in pPb collisions at root s(NN) = 5.02 TeV (vol 79, 277, 2019)
No full textIn this article the author name Luigi Calligaris was incorrectly written as A. Calligaris. The original article has been corrected
- …
