Measurement of neutral current e+/-p cross sections at high Bjorken x with the ZEUS detector

The neutral current e+/-p cross section has been measured up to values of Bjorken x of approximately 1 with the ZEUS detector at HERA using an integrated luminosity of 187 inv. pb of e-p and 142 inv. pb of e+p collisions at sqrt(s) = 318GeV. Differential cross sections in x and Q2, the exchanged boson virtuality, are presented for Q2 geq 725GeV2. An improved reconstruction method and greatly increased amount of data allows a finer binning in the high-x region of the neutral current cross section and leads to a measurement with much improved precision compared to a similar earlier analysis. The measurements are compared to Standard Model expectations based on a variety of recent parton distribution functions.Comment: 39 pages, 9 figure

Measurement of the cross-section ratio sigma_{psi(2S)}/sigma_{J/psi(1S)} in deep inelastic exclusive ep scattering at HERA

The exclusive deep inelastic electroproduction of $\psi(2S)$ and $J/\psi(1S)$ at an $ep$ centre-of-mass energy of 317 GeV has been studied with the ZEUS detector at HERA in the kinematic range $2 < Q^2 < 80$ GeV$^2$, $30 < W < 210$ GeV and $|t| < 1$ GeV$^2$, where $Q^2$ is the photon virtuality, $W$ is the photon-proton centre-of-mass energy and $t$ is the squared four-momentum transfer at the proton vertex. The data for $2 < Q^2 < 5$ GeV$^2$ were taken in the HERA I running period and correspond to an integrated luminosity of 114 pb$^{-1}$. The data for $5 < Q^2 < 80$ GeV$^2$ are from both HERA I and HERA II periods and correspond to an integrated luminosity of 468 pb$^{-1}$. The decay modes analysed were $\mu^+\mu^-$ and $J/\psi(1S) \,\pi^+\pi^-$ for the $\psi(2S)$ and $\mu^+\mu^-$ for the $J/\psi(1S)$. The cross-section ratio $\sigma_{\psi(2S)}/\sigma_{J/\psi(1S)}$ has been measured as a function of $Q^2, W$ and $t$. The results are compared to predictions of QCD-inspired models of exclusive vector-meson production.Comment: 24 pages, 8 figure

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

Measurement of the cross-section ratio sigma(psi(2S))/sigma(J/psi(1S)) in deep inelastic exclusive ep scattering at HERA

The exclusive deep inelastic electroproduction of ψ(2S) and J/ψ(1S) at an ep centre-of-mass energy of 317 GeV has been studied with the ZEUS detector at HERA in the kinematic range 2<Q2<80 GeV2, 30<W<210 GeV and |t|<1 GeV2, where Q2 is the photon virtuality, W is the photon–proton centre-of-mass energy and t is the squared four-momentum transfer at the proton vertex. The data for 2<Q2<5 GeV2 were taken in the HERA I running period and correspond to an integrated luminosity of 114 pb−1. The data for 5<Q2<80 GeV2 are from both HERA I and HERA II periods and correspond to an integrated luminosity of 468 pb−1. The decay modes analysed were μ+μ− and View the MathML source for the ψ(2S) and μ+μ− for the J/ψ(1S). The cross-section ratio σψ(2S)/σJ/ψ(1S) has been measured as a function of View the MathML source  and t. The results are compared to predictions of QCD-inspired models of exclusive vector-meson production

Erratum: Measurement of D^{∗±} production in deep inelastic scattering at HERA

The ZEUS collaborationIn the analysis for our paper on D* production, the beauty contribution was erroneously subtracted twice in the extraction of the reduced cross sections. This affected tables 9 and 10 as well as figures 9 and 10 that are reproduced here in a corrected version. The kinematical acceptances shown in the last colum of table 10 have been also corrected since they were calculated with a different value for the charm fragmentation fraction than what was used in the rest of the analysis and reported in the text. A misprint was found in table 7: the value in the third column at four rows from the bottom should read 49.8, not 59.8. Finally, one of the authors was missing from the author list: C. Uribe-Estrada (Department of Physics, University of Oxford, United Kingdom).Article funded by SCOAP

Measurement of beauty and charm production in deep inelastic scattering at HERA and measurement of the beauty-quark mass

The ZEUS collaborationThe production of beauty and charm quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared 5 < Q^2 < 1000 GeV^2 using an integrated luminosity of 354 pb^{−1}. The beauty and charm content in events with at least one jet have been extracted using the invariant mass of charged tracks associated with secondary vertices and the decay-length significance of these vertices. Differential cross sections as a function of Q^2, Bjorken x, jet trans- verse energy and pseudorapidity were measured and compared with next-to-leading-order QCD calculations. The beauty and charm contributions to the proton structure functions were extracted from the double-differential cross section as a function of x and Q^2. The running beauty-quark mass, m_b at the scale m_b , was determined from a QCD fit at next-to-leading order to HERA data for the first time and found to be m_b(m_b) = 4.07 ± 0.14(fit)_{−0.07}^{+0.01}(mod.)_{−0.00}^{+0.05}(param.)_{−0.05}^{+0.08}(theo.)GeV.We appreciate the contributions to the construction, maintenance and operation of the ZEUS detector of 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. It is a pleasure to thank the ABKM, CTEQ, JR and MSTW groups that provided the predictions for F_2^{b\overline{b}} shown in figure 12. We gratefully acknowledge the advice from S. Alekhin and R. Plačakytė concerning the appropriate usage of OPENQCDRAD and HERAFitter. Article funded by SCOAP

Molekuliarno-épidemiologicheskie osobennosti variantov VICh-1, tsirkuliruiushchikh sredi shpritsevykh narkomanov na territorii SNG

Different strains of HIV-1, circulating among drug addicts introducing drugs intravenously and detected on the territories of Russia, Ukraine and Belarus, have been characterized by the methods of the comparative analysis of genetic sequences of different variants of HIV (gene typing) and the study of the immunological properties of autoimmune sera (serotyping

Lithosphere-atmosphere-ionosphere coupling as governing mechanism for preseismic short-term events in atmosphere and ionosphere

International audienceWe present a general concept of mechanisms of preseismic phenomena in the atmosphere and ionosphere. After short review of observational results we conclude: 1. Upward migration of fluid substrate matter (bubble) can lead to ousting of the hot water/gas near the ground surface and cause an earthquake (EQ) itself in the strength-weakened area; 2. Thus, time and place of the bubble appearance could be random values, but EQ, geochemistry anomaly and foreshocks (seismic, SA and ULF electromagnetic ones) are casually connected; 3. Atmospheric perturbation of temperature and density could follow preseismic hot water/gas release resulting in generation of atmospheric gravity waves (AGW) with periods in a range of 6?60min; 4. Seismo-induced AGW could lead to modification of the ionospheric turbulence and to the change of over-horizon radio-wave propagation in the atmosphere, perturbation of LF waves in the lower ionosphere and ULF emission depression at the ground