Reflective Elastic Scattering at LHC

We discuss effects of reflective scattering for hadron and heavy nuclei collisions at the LHC and asymptotical energies. It is shown that the reflective scattering might lead to decreasing matter density with energy beyond the LHC energies. Limiting form of energy dependence of hadron density is obtained. Unitarity upper bound for the absolute value of the real part of elastic scattering amplitude and two-particle inelastic binary reactions amplitudes in impact parameter representation is two times less than the corresponding bound for the imaginary part of the elastic scattering amplitude. The former limit restricts a possible odderon contribution.Comment: 7 pages, 1 figure, talk given at the EDS'09 Conferenc

Increasing the Uniformity of Application of Mineral and Lime Fertilizers

Introduction. Modern agricultural production is based on the use of resource-saving technologies for agricultural production. An important element of these technologies is the use of mineral fertilizers and special importance is given to the uniformity of applying them. Aim of the Study. The study is aimed at improving the process of applying mineral and lime fertilizers through the development of a pneumatic centrifugal working body. Materials and Methods. For the theoretical studies, there were used the principles of mathematics and theoretical mechanics. The experimental studies were carried out at the testing ground of the Institute of Mechanics and Energy of Mordovia State University. The quality assessment of the operation of the unit equipped with experimental working bodies was carried out in accordance with GOST 28714-2007. Results. To better distribute mineral fertilizers of heterogeneous granulometric composition over the field surface, there has been proposed a working element, the operating principle of which is based on the total use of mechanical and pneumatic effects on the granules of the agricultural inputs. The use of the developed working bodies makes it possible to increase the uniformity of fertilizer application by 17.6%. Discussion and Conclusion. As a result of the conducted study, there has been proven the effectiveness of using the developed pneumocentrifugal working body, which makes it possible to increase the uniformity of distribution of mineral and lime fertilizers

Search for supersymmetry in proton-proton collisions at √s = 13 TeV in events with high-momentum Z bosons and missing transverse momentum

A search for new physics in events with two highly Lorentz-boosted Z bosons and large missing transverse momentum is presented. The analyzed proton-proton collision data, corresponding to an integrated luminosity of 137 fb−1, were recorded at √s = 13 TeV by the CMS experiment at the CERN LHC. The search utilizes the substructure of jets with large radius to identify quark pairs from Z boson decays. Backgrounds from standard model processes are suppressed by requirements on the jet mass and the missing transverse momentum. No significant excess in the event yield is observed beyond the number of background events expected from the standard model. For a simplified supersymmetric model in which the Z bosons arise from the decay of gluinos, an exclusion limit of 1920 GeV on the gluino mass is set at 95% confidence level. This is the first search for beyond-standard-model production of pairs of boosted Z bosons plus large missing transverse momentum

Search for decays of the 125 GeV Higgs boson into a Z boson and a ρ or ϕ meson

Decays of the 125 GeV Higgs boson into a Z boson and a ρ0(770) or ϕ(1020) meson are searched for using proton-proton collision data collected by the CMS experiment at the LHC at √s = 13 TeV. The analysed data set corresponds to an integrated luminosity of 137 fb−1. Events are selected in which the Z boson decays into a pair of electrons or a pair of muons, and the ρ and ϕ mesons decay into pairs of pions and kaons, respectively. No significant excess above the background model is observed. As different polarization states are possible for the decay products of the Z boson and ρ or ϕ mesons, affecting the signal acceptance, scenarios in which the decays are longitudinally or transversely polarized are considered. Upper limits at the 95% confidence level on the Higgs boson branching fractions into Zρ and Zϕ are determined to be 1.04-1.31% and 0.31-0.40%, respectively, where the ranges reflect the considered polarization scenarios; these values are 740-940 and 730-950 times larger than the respective standard model expectations. These results constitute the first experimental limits on the two decay channels