Fabrication by Spin-Coating and Optical Characterization of Poly(styrene-co- acrylonitrile) Thin Films

The optical characteristics of poly(styrene-co- acrylonitrile) thin films obtained by spin- coating of polymer blend in tetrahydrofuran were investigated by spectroscopic ellipsometry, spectrophotometry, and atomic force microscopy. Film thickness can be broadly varied by changing the polymer concentration.The film thickness dependence on PSAN concentration shows a non- linear behavior that can be explained by a concentration-dependent viscosity. According to previously proposed models, prepared solutions are close to the concentrated solution regime. Films show a broad transparency range and refractive index independent of film thickness. The refractive index values range from 1.55 to 1.6 in the visible range. Thermal treatment revealed good stability of the films up to 220 °C and a progressive deterioration for larger temperatures, with evident damage at 300 °C. UV- induced photodegradation was observed and results showed a progressive decrease of transmittance in the range between 200 and 300 nm but PSAN thin films show no changes when exposed to light from a solar illuminator. These investigations indicate that PSAN is an excellent candidate for thin film polymer-based optical uses like interference coatings or encapsulation of solar cell

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

Sustav za prikaz i pohranu tijeka zaključivanja u konstruiranju

Cilj ovog rada je izraditi programski sustav koji će omogućiti prikazivanje i spremanje tijeka promišljanja i odlučivanja u procesu konstruiranja. Rad se sastoji od dva glavna dijela, razmatranja teorijskih osnova u prvom dijelu i izrade programskog sustava. U uvodnom dijelu ukratko su razmotrene osnove razvoja proizvoda i konstruiranja, kao i razlozi za prikazivanje tijeka promišljanja u procesu konstruiranja. Drugi dio, koji pokriva treće i četvrto poglavlje bavi se sustavima za upravljanje podacima o proizvodu, koji imaju za cilj olakšati i ubrzati procese razvoja i konstruiranja. Nakon toga, u petom poglavlju postavljene su teoretske osnove za izradu adekvatnog programskog sustava, za koji nakon toga postavljeni zahtjevi. Sedmo poglavlje objašnjava funkcije i svojstva izrađenog programskog sustava, te je nakon toga prikazan primjer njenog korištenja. U završnom dijelu rada razmotrene su mogućnosti promjene i poboljšanja razvijenog programskog sustava, kao i mogućnosti njegovog povezivanja s ostalim elementima sustava upravljanja znanjem

Sustav za prikaz i pohranu tijeka zaključivanja u konstruiranju

Cilj ovog rada je izraditi programski sustav koji će omogućiti prikazivanje i spremanje tijeka promišljanja i odlučivanja u procesu konstruiranja. Rad se sastoji od dva glavna dijela, razmatranja teorijskih osnova u prvom dijelu i izrade programskog sustava. U uvodnom dijelu ukratko su razmotrene osnove razvoja proizvoda i konstruiranja, kao i razlozi za prikazivanje tijeka promišljanja u procesu konstruiranja. Drugi dio, koji pokriva treće i četvrto poglavlje bavi se sustavima za upravljanje podacima o proizvodu, koji imaju za cilj olakšati i ubrzati procese razvoja i konstruiranja. Nakon toga, u petom poglavlju postavljene su teoretske osnove za izradu adekvatnog programskog sustava, za koji nakon toga postavljeni zahtjevi. Sedmo poglavlje objašnjava funkcije i svojstva izrađenog programskog sustava, te je nakon toga prikazan primjer njenog korištenja. U završnom dijelu rada razmotrene su mogućnosti promjene i poboljšanja razvijenog programskog sustava, kao i mogućnosti njegovog povezivanja s ostalim elementima sustava upravljanja znanjem

Sustav za prikaz i pohranu tijeka zaključivanja u konstruiranju

Cilj ovog rada je izraditi programski sustav koji će omogućiti prikazivanje i spremanje tijeka promišljanja i odlučivanja u procesu konstruiranja. Rad se sastoji od dva glavna dijela, razmatranja teorijskih osnova u prvom dijelu i izrade programskog sustava. U uvodnom dijelu ukratko su razmotrene osnove razvoja proizvoda i konstruiranja, kao i razlozi za prikazivanje tijeka promišljanja u procesu konstruiranja. Drugi dio, koji pokriva treće i četvrto poglavlje bavi se sustavima za upravljanje podacima o proizvodu, koji imaju za cilj olakšati i ubrzati procese razvoja i konstruiranja. Nakon toga, u petom poglavlju postavljene su teoretske osnove za izradu adekvatnog programskog sustava, za koji nakon toga postavljeni zahtjevi. Sedmo poglavlje objašnjava funkcije i svojstva izrađenog programskog sustava, te je nakon toga prikazan primjer njenog korištenja. U završnom dijelu rada razmotrene su mogućnosti promjene i poboljšanja razvijenog programskog sustava, kao i mogućnosti njegovog povezivanja s ostalim elementima sustava upravljanja znanjem

Search for direct top squark pair production in final states with two leptons in s=13\sqrt{s} = 13 TeV pppp collisions with the ATLAS detector

International audienceThe results of a search for direct pair production of top squarks in events with two opposite-charge leptons (electrons or muons) are reported, using $36.1~\hbox {fb}^{-1}$ of integrated luminosity from proton–proton collisions at $\sqrt{s}=13$ TeV collected by the ATLAS detector at the Large Hadron Collider. To cover a range of mass differences between the top squark $\tilde{t}$ and lighter supersymmetric particles, four possible decay modes of the top squark are targeted with dedicated selections: the decay $\tilde{t} \rightarrow b \tilde{\chi }_{1}^{\pm }$ into a b-quark and the lightest chargino with $\tilde{\chi }_{1}^{\pm } \rightarrow W \tilde{\chi }_{1}^{0}$ , the decay $\tilde{t} \rightarrow t \tilde{\chi }_{1}^{0}$ into an on-shell top quark and the lightest neutralino, the three-body decay $\tilde{t} \rightarrow b W \tilde{\chi }_{1}^{0}$ and the four-body decay $\tilde{t} \rightarrow b \ell \nu \tilde{\chi }_{1}^{0}$ . No significant excess of events is observed above the Standard Model background for any selection, and limits on top squarks are set as a function of the $\tilde{t}$ and $\tilde{\chi }_{1}^{0}$ masses. The results exclude at 95% confidence level $\tilde{t}$ masses up to about 720 GeV, extending the exclusion region of supersymmetric parameter space covered by previous searches

Measurements of ttˉt\bar{t} differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in pppp collisions at s=13 \sqrt{s}=13\, TeV using the ATLAS detector

Measurements are made of differential cross-sections of highly boosted pair-produced top quarks as a function of top-quark and $t\bar{t}$ system kinematic observables using proton--proton collisions at a center-of-mass energy of $\sqrt{s} = 13$ TeV. The data set corresponds to an integrated luminosity of $36.1$ fb$^{-1}$, recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Events with two large-radius jets in the final state, one with transverse momentum $p_{\rm T} > 500$ GeV and a second with $p_{\rm T}>350$ GeV, are used for the measurement. The top-quark candidates are separated from the multijet background using jet substructure information and association with a $b$-tagged jet. The measured spectra are corrected for detector effects to a particle-level fiducial phase space and a parton-level limited phase space, and are compared to several Monte Carlo simulations by means of calculated $\chi^2$ values. The cross-section for $t\bar{t}$ production in the fiducial phase-space region is $292 \pm 7 \ \rm{(stat)} \pm 76 \rm{(syst)}$ fb, to be compared to the theoretical prediction of $384 \pm 36$ fb

Searches for the ZγZ\gamma decay mode of the Higgs boson and for new high-mass resonances in pppp collisions at s=13\sqrt{s} = 13 TeV with the ATLAS detector

International audienceThis article presents searches for the Zγ decay of the Higgs boson and for narrow high-mass resonances decaying to Zγ, exploiting Z boson decays to pairs of electrons or muons. The data analysis uses 36.1 fb$^{−1}$ of pp collisions at $\sqrt{s}=13$ recorded by the ATLAS detector at the CERN Large Hadron Collider. The data are found to be consistent with the expected Standard Model background. The observed (expected — assuming Standard Model pp → H → Zγ production and decay) upper limit on the production cross section times the branching ratio for pp → H → Zγ is 6.6. (5.2) times the Standard Model prediction at the 95% confidence level for a Higgs boson mass of 125.09 GeV. In addition, upper limits are set on the production cross section times the branching ratio as a function of the mass of a narrow resonance between 250 GeV and 2.4 TeV, assuming spin-0 resonances produced via gluon-gluon fusion, and spin-2 resonances produced via gluon-gluon or quark-antiquark initial states. For high-mass spin-0 resonances, the observed (expected) limits vary between 88 fb (61 fb) and 2.8 fb (2.7 fb) for the mass range from 250 GeV to 2.4 TeV at the 95% confidence level

Measurements of ttˉt\bar{t} differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in pppp collisions at s=13 \sqrt{s}=13\, TeV using the ATLAS detector

Measurements are made of differential cross-sections of highly boosted pair-produced top quarks as a function of top-quark and $t\bar{t}$ system kinematic observables using proton--proton collisions at a center-of-mass energy of $\sqrt{s} = 13$ TeV. The data set corresponds to an integrated luminosity of $36.1$ fb$^{-1}$, recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Events with two large-radius jets in the final state, one with transverse momentum $p_{\rm T} > 500$ GeV and a second with $p_{\rm T}>350$ GeV, are used for the measurement. The top-quark candidates are separated from the multijet background using jet substructure information and association with a $b$-tagged jet. The measured spectra are corrected for detector effects to a particle-level fiducial phase space and a parton-level limited phase space, and are compared to several Monte Carlo simulations by means of calculated $\chi^2$ values. The cross-section for $t\bar{t}$ production in the fiducial phase-space region is $292 \pm 7 \ \rm{(stat)} \pm 76 \rm{(syst)}$ fb, to be compared to the theoretical prediction of $384 \pm 36$ fb