Modeling the process of producing hydrogen from methane

Using the chemical reactions that accompany the production of syngas via the steam reforming of methane as a basis, the differential material balance equations were derived and solved for all conversion products on an aluminum/nickel catalyst. For the following stage of hydrogen synthesis on an iron/chromium catalyst, the system of two differential equations of the material balance of the direct and reverse reactions of steam carbon monoxide conversion was obtained and solved. The analytical solutions were compared with the experiment. © 2013 Pleiades Publishing, Ltd

Search for Higgs Boson at LHC in the Reaction pp->gamma+gamma+jet at a Low Luminosity

We discuss the SM Higgs discovery potential of the LHC in the channel pp->H+jet->gamma+gamma+jet when the jet is observed at sufficiently high Pt and a small rapidity to be reliably identified. We calculate all the signal subprocesses and the irreducible background with realistic kinematical cuts. The reducible QCD background is also estimated. We conclude that the channel gamma+gamma+jet can give about 120-200 signal events for Higgs mass MH=100-140 GeV at the integrated luminosity of 30 inverse fb. This signal rate should be compared with only 330-600 events for the irreducible background per two-photon invariant mass interval of 2 GeV. We estimate the QCD reducible background at the level of 20% of the irreducible one. Thus, one may hope that the Higgs boson can be discovered already during the LHC operation at a low luminosity. At a high luminosity the observation of several hundreds of high Pt Higgs bosons in this channel will be possible with significance higher than 15 for L=100 inverse fb.Comment: 21 pages (LaTeX code, epsf.sty), 2 tables, 9 figures; to appear in the Proceedings of XIIth International Workshop on High Energy Physics and Quantum Field Theory (QFTHEP-97), Samara, Russia, September 4-10, 199

Optimization of operating parameters of thermochemical reactor with electric of retort

На основании уравнений теплового и материального балансов термохимического реактора при воздушной конверсии метана проведена оптимизация параметров по максимальному выходу водорода при минимальной затрате электрической энергии, идущей на обогрев реторты. Расчетный состав продуктов конверсии хорошо соответствует экспериментально полученному.Equations of heat and gas balance thermochemical reactor at air conversion of methane are used for optimizing the parameters with respect to maximum yield of hydrogen at minimum consumption of electric energy for heating the retort. The computed composition of conversion products agrees well with that obtained experimentally

CompHEP: specialized package for automatic calculations of elementary particle decays and collisions

At present time when a new generation of TeV colliders are beginning to operate one needs to calculate cross-sections for a great number of various reactions. Such calculations are united in the framework of the collider physical program, providing definite predictions how to detect the signatures of the new physics and separate them from the background. The CompHEP package was created for calculation of decay and high energy collision processes of elementary particles in the lowest order (tree) approximation. The main idea put into the CompHEP was to make available passing from the lagrangian to the final distributions effectively with the high level of automatization what is extremely needed in collider physics

Evidence for WW production from double-parton interactions in proton–proton collisions at √s = 13 TeV

A search for WW production from double-parton scattering processes using same-charge electron-muon and dimuon events is reported, based on proton-proton collision data collected at a center-of-mass energy of 13 TeV. The analyzed data set corresponds to an integrated luminosity of 77.4fb⁻¹, collected using the CMS detector at the LHC in 2016 and 2017. Multivariate classifiers are used to discriminate between the signal and the dominant background processes. A maximum likelihood fit is performed to extract the signal cross section. This leads to the first evidence for WW production via double-parton scattering, with a significance of 3.9 standard deviations. The measured inclusive cross section is 1.41±0.28(stat)±0.28(syst)pb

Searches for physics beyond the standard model with the M_(T2) variable in hadronic final states with and without disappearing tracks in proton–proton collisions at √s = 13 TeV

Two related searches for phenomena beyond the standard model (BSM) are performed using events with hadronic jets and significant transverse momentum imbalance. The results are based on a sample of proton–proton collisions at a center-of-mass energy of 13TeV, collected by the CMS experiment at the LHC in 2016–2018 and corresponding to an integrated luminosity of 137fb⁻¹. The first search is inclusive, based on signal regions defined by the hadronic energy in the event, the jet multiplicity, the number of jets identified as originating from bottom quarks, and the value of the kinematic variable M_(T2) for events with at least two jets. For events with exactly one jet, the transverse momentum of the jet is used instead. The second search looks in addition for disappearing tracks produced by BSM long-lived charged particles that decay within the volume of the tracking detector. No excess event yield is observed above the predicted standard model background. This is used to constrain a range of BSM models that predict the following: the pair production of gluinos and squarks in the context of supersymmetry models conserving R-parity, with or without intermediate long-lived charginos produced in the decay chain; the resonant production of a colored scalar state decaying to a massive Dirac fermion and a quark; or the pair production of scalar and vector leptoquarks each decaying to a neutrino and a top, bottom, or light-flavor quark. In most of the cases, the results obtained are the most stringent constraints to date

Search for low mass vector resonances decaying into quark-antiquark pairs in proton-proton collisions at √s = 13 TeV

A search for low mass narrow vector resonances decaying into quark-antiquark pairs is presented. The analysis is based on data collected in 2017 with the CMS detector at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 41.1  fb⁻¹. The results of this analysis are combined with those of an earlier analysis based on data collected at the same collision energy in 2016, corresponding to 35.9  fb⁻¹. Signal candidates will be recoiling against initial state radiation and are identified as energetic, large-radius jets with two pronged substructure. The invariant jet mass spectrum is probed for a potential narrow peaking signal over a smoothly falling background. No evidence for such resonances is observed within the mass range of 50–450 GeV. Upper limits at the 95% confidence level are set on the coupling of narrow resonances to quarks, as a function of the resonance mass. For masses between 50 and 300 GeV these are the most sensitive limits to date. This analysis extends the earlier search to a mass range of 300–450 GeV, which is probed for the first time with jet substructure techniques