Kaon pair production in proton-nucleus collisions at 2.83 GeV kinetic energy

The production of non-phi K+K- pairs by protons of 2.83 GeV kinetic energy on C, Cu, Ag, and Au targets has been investigated using the COSY-ANKE magnetic spectrometer. The K- momentum dependence of the differential cross section has been measured at small angles over the 0.2--0.9 GeV/c range. The comparison of the data with detailed model calculations indicates an attractive K- -nucleus potential of about -60 MeV at normal nuclear matter density at a mean momentum of 0.5 GeV/c. However, this approach has difficulty in reproducing the smallness of the observed cross sections at low K- momenta.Comment: 7 pages, 5 figures, 1 tabl

The production of K+K- pairs in proton-proton collisions at 2.83 GeV

Differential and total cross sections for the pp -> ppK+K- reaction have been measured at a proton beam energy of 2.83 GeV using the COSY-ANKE magnetic spectrometer. Detailed model descriptions fitted to a variety of one-dimensional distributions permit the separation of the pp -> pp phi cross section from that of non-phi production. The differential spectra show that higher partial waves represent the majority of the pp -> pp phi total cross section at an excess energy of 76 MeV, whose energy dependence would then seem to require some s-wave phi-p enhancement near threshold. The non-phi data can be described in terms of the combined effects of two-body final state interactions using the same effective scattering parameters determined from lower energy data.Comment: 12 pages, 12 figures, 3 table

Particle spectrum in the modified NMSSM in the strong Yukawa coupling limit

A theoretical analysis of solutions of renormalisation group equations in the MSSM corresponding to the quasi-fixed point conditions shows that the mass of the lightest Higgs boson in this case does not exceed $94\pm 5\text{GeV}$. It means that a substantial part of the parameter space of the MSSM is practically excluded by existing experimental data from LEP II. In the NMSSM the upper bound on the lightest Higgs boson mass reaches its maximum in the strong Yukawa coupling regime, when Yukawa constants are considerably larger the gauge ones on the Grand Unification scale. In this paper a particle spectrum in a simple modification of NMSSM which leads to a self-consistent solution in the considered region of the parameter space is studied. This model allows one to get $m_h\sim 125\text{GeV}$ even for comparatively low values of $\tan\beta\ge 1.9$. For an analysis of the Higgs boson spectrum and neutralino spectrum a method for diagonalisation of mass matrices proposed formerly is used. The mass of the lightest Higgs boson in this model does not exceed $130.5\pm 3.5\text{GeV}$.Comment: 34 pages, 5 figures included, LaTeX 2

Nuclear matter at high density: Phase transitions, multiquark states, and supernova outbursts

Phase transition from hadronic matter to quark-gluon matter is discussed for various regimes of temperature and baryon number density. For small and medium densities, the phase transition is accurately described in the framework of the Field Correlation Method, whereas at high density predictions are less certain and leave room for the phenomenological models. We study formation of multiquark states (MQS) at zero temperature and high density. Relevant MQS components of the nuclear matter can be described using a previously developed formalism of the quark compound bags (QCB). Partial-wave analysis of nucleon-nucleon scattering indicates the existence of 6QS which manifest themselves as poles of $P$-matrix. In the framework of the QCB model, we formulate a self-consistent system of coupled equations for the nucleon and 6QS propagators in nuclear matter and the G-matrix. The approach provides a link between high-density nuclear matter with the MQS components and the cumulative effect observed in reactions on the nuclei, which requires the admixture of MQS in the wave functions of nuclei kinematically. 6QS determine the natural scale of the density for a possible phase transition into the MQS phase of nuclear matter. Such a phase transition can lead to dynamic instability of newly born protoneutron stars and dramatically affect the dynamics of supernovae. Numerical simulations show that the phase transition may be a good remedy for the triggering supernova explosions in the spherically symmetric supernova models. A specific signature of the phase transition is an additional neutrino peak in the neutrino light curve. For a Galactic core-collapse supernova, such a peak could be resolved by the present neutrino detectors. The possibility of extracting the parameters of the phase of transition from observation of the neutrino signal is discussed also.Comment: 57 pages, 22 figures, 7 tables; RevTeX 4; submitted to Phys. Atom. Nuc

Momentum dependence of the phi-meson nuclear transparency

The production of phi mesons in proton collisions with C, Cu, Ag, and Au targets has been studied via the phi -> K+K- decay at an incident beam energy of 2.83 GeV using the ANKE detector system at COSY. For the first time, the momentum dependence of the nuclear transparency ratio, the in-medium phi width, and the differential cross section for phi meson production at forward angles have been determined for these targets over the momentum range of 0.6 - 1.6 GeV/c. There are indications of a significant momentum dependence in the value of the extracted phi width, which corresponds to an effective phi-N absorption cross section in the range of 14 - 21 mb.Comment: 9 pages, 5 figure

Исследование процесса окислительного хлорирования метана при повышенных давлениях

The process of the oxidative chlorination of methane carried out in a flow reactor was investigated in the temperature range of 370–400°C under a pressure of 1–9 ata. The catalyst is a mixture of copper chloride, potassium chloride and lanthanum chloride on a porous support. The molar ratio CuCl2:KCl:LaCl3 is 1:1:0.3. The process was studied in an excess of methane at the reactants ratio CH4:HCl:O2 12:2:1 and 13.5:1:0.5. It was shown experimentally that the productivity of the methane oxychlorination reactor increases proportionally to pressure in the degree ~ 0.85. It was found that an increase in the selectivity of the methane oxychlorination process to the desired product – methyl chloride – (more than 90%) is achieved by increasing the ratio of methane to the sum of hydrogen chloride and oxygen.Процесс окислительного хлорирования метана, проводимый в проточном реакторе, изучался в интервале температур 370–400°С при давлении 1–9 ата. В качестве катализатора использовалась смесь хлоридов меди, калия и лантана в мольном соотношении 1:1:0.3, нанесенная на пористый носитель. Процесс изучался в избытке метана при соотношении реагентов CH4:HCl:O2, равном 12:2:1 и 13.5:1:0.5

Photoproduction of isolated photons, inclusively and with a jet, at HERA

ZEUS CollaborationThe photoproduction of isolated photons, both inclusive and together with a jet, has been measured with the ZEUS detector at HERA using an integrated luminosity of 374 pb^{−1}. Differential cross sections are presented in the isolated-photon transverse-energy and pseudorapidity ranges 6 < E^γ_T < 15 GeV and −0.7 < η^γ < 0.9, and for jet transverse-energy and pseudorapidity ranges 4 < E^{jet}_T < 35 GeV and −1.5 <η^{jet} < 1.8, for exchanged-photon virtualities Q^2 < 1 GeV^2. Differential cross sections are also presented for inclusive isolated-photon production as functions of the transverse energy and pseudorapidity of the photon. Higher-order theoretical calculations are compared to the results.We appreciate the contributions to the construction, maintenance and operation of the ZEUS detector made by many people who are not listed as authors. The HERA machine group and the DESY computing staff are especially acknowledged for their success in providing excellent operation of the collider and the data-analysis environment. We thank the DESY directorate for their strong support and encouragement. We also thank M. Fontannaz, G. Heinrich, A. Lipatov, M. Malyshev and N. Zotov for providing assistance and theoretical results. Funded by SCOAP

Methods of Testing of Individual Auditing Tasks by External Quality Controllers

The article describes the sampling techniques to verify the quality of performance of auditing tasks and duties, among which it is advisable to use non-statistical and varied sampling methods. During the selection of the tasks for sampling methods, the following benchmarks can be chosen as the example: groups of the auditors of an organization; specialization of the entities that undergo the auditory check up; the type of service rendered; the cost of auditing tasks. When analyzing the selected sample of aggregate concept and design it is necessary to take into account the specifics of the auditing quality control activities. Its main idea is the fact that, unlike auditing, inspection methods are of a more formal approach. Exploring the working papers of auditors, quality controllers use one of the methods of quality control of auditors - the inspection of the automation of the planning process for each specific task. During the test, the external quality controllers assess the level of automation of the work of the auditors. You can use different approaches to this assessment, for example, the introduction of a three-point scale computerization of the work of the auditors. For external supervisors it is important to check the quality of the auditing plan and the auditing program of an organization. The described methods of quality control of the individual planning of auditing tasks ensure at least the minimum confidence in the effectiveness of such planning

Study on methane oxydative chlorination process under pressure

The process of the oxidative chlorination of methane carried out in a flow reactor was investigated in the temperature range of 370–400°C under a pressure of 1–9 ata. The catalyst is a mixture of copper chloride, potassium chloride and lanthanum chloride on a porous support. The molar ratio CuCl2:KCl:LaCl3 is 1:1:0.3. The process was studied in an excess of methane at the reactants ratio CH4:HCl:O2 12:2:1 and 13.5:1:0.5. It was shown experimentally that the productivity of the methane oxychlorination reactor increases proportionally to pressure in the degree ~ 0.85. It was found that an increase in the selectivity of the methane oxychlorination process to the desired product – methyl chloride – (more than 90%) is achieved by increasing the ratio of methane to the sum of hydrogen chloride and oxygen