A semisynthetic glycoconjugate provides expanded cross-serotype protection against Streptococcus pneumoniae

Streptococcus pneumoniae (S. pneumoniae) infections are the leading cause of child mortality globally. Current vaccines fail to induce a protective immune response towards a conserved part of the pathogen, resulting in new serotypes causing disease. Therefore, new vaccine strategies are urgently needed. Described is a two-pronged approach combining S. pneumoniae proteins, pneumolysin (Ply) and pneumococcal surface protein A (PspA), with a precisely defined synthetic oligosaccharide, whereby the carrier protein acts as a serotype-independent antigen to provide additional protection. Proof of concept in mice and swine models revealed that the conjugates inhibited colonization of the nasopharynx, decreased the bacterial load and reduced disease severity in the bacteria challenge model. Immunization of piglets provided the first evidence for the immunogenicity and protective potential of synthetic glycoconjugate vaccine in a large animal model. A combination of synthetic oligosaccharides with proteins from the target pathogen opens the path to create broadly cross-protective (“universal”) pneumococcal vaccines

Measurement of (anti)deuteron and (anti)proton production in DIS at HERA

The first observation of (anti)deuterons in deep inelastic scattering at HERA has been made with the ZEUS detector at a centre-of-mass energy of 300--318 GeV using an integrated luminosity of 120 pb-1. The measurement was performed in the central rapidity region for transverse momentum per unit of mass in the range 0.3<p_T/M<0.7. The particle rates have been extracted and interpreted in terms of the coalescence model. The (anti)deuteron production yield is smaller than the (anti)proton yield by approximately three orders of magnitude, consistent with the world measurements.Comment: 26 pages, 9 figures, 5 tables, submitted to Nucl. Phys.

Inclusive-jet Photoproduction at HERA and Determination of α \u3csub\u3es\u3c/sub\u3e

Inclusive-jet cross sections have been measured in the reaction ep→e+jet+X for photon virtuality Q 2γp centre-of-mass energies in the region 142γp-1. Jets were identified using the k T, anti-k T or SIScone jet algorithms in the laboratory frame. Single-differential cross sections are presented as functions of the jet transverse energy, ETjet, and pseudorapidity, jet, for jets with ETjet\u3e17 GeV and -1\u3c je

High-E_T dijet photoproduction at HERA

The cross section for high-E_T dijet production in photoproduction has been measured with the ZEUS detector at HERA using an integrated luminosity of 81.8 pb-1. The events were required to have a virtuality of the incoming photon, Q^2, of less than 1 GeV^2 and a photon-proton centre-of-mass energy in the range 142 < W < 293 GeV. Events were selected if at least two jets satisfied the transverse-energy requirements of E_T(jet1) > 20 GeV and E_T(jet2) > 15 GeV and pseudorapidity requirements of -1 < eta(jet1,2) < 3, with at least one of the jets satisfying -1 < eta(jet) < 2.5. The measurements show sensitivity to the parton distributions in the photon and proton and effects beyond next-to-leading order in QCD. Hence these data can be used to constrain further the parton densities in the proton and photon.Comment: 36 pages, 13 figures, 20 tables, including minor revisions from referees. Accepted by Phys. Rev.

Search for First-generation Leptoquarks at HERA

A search for first-generation leptoquarks was performed in electron-proton and positron-proton collisions recorded with the ZEUS detector at HERA in 2003-2007 using an integrated luminosity of 366pb-1. Final states with an electron and jets or with missing transverse momentum and jets were analyzed, searching for resonances or other deviations from the standard model predictions. No evidence for any leptoquark signal was found. The data were combined with data previously taken at HERA, resulting in a total integrated luminosity of 498pb-1. Limits on the Yukawa coupling, λ, of leptoquarks were set as a function of the leptoquark mass for different leptoquark types within the Buchmüller-Rückl-Wyler model. Leptoquarks with a coupling λ=0.3 are excluded for masses up to 699 GeV. © 2012 American Physical Society

Measurement of Inelastic J/ψ and ψ′ Photoproduction at HERA

The cross sections for inelastic photoproduction of J/ψ and ψ′ mesons have been measured in ep collisions with the ZEUS detector at HERA, using an integrated luminosity of 468 pb-1 collected in the period 1996-2007. The ψ′ to J/ψ cross section ratio was measured in the range 0.55 \u3c z \u3c 0.9 and 60 \u3c W \u3c 190 GeV as a function of W, z and pT. Here W denotes the photon-proton centre-of-mass energy, z is the fraction of the incident photon energy carried by the meson and p T is the transverse momentum of the meson with respect to the beam axis. The J/ψ cross sections were measured for 0.1 \u3c z \u3c 0.9, 60 \u3c W \u3c 240 GeV and pT \u3e 1 GeV. Theoretical predictions within the non-relativistic QCD framework including NLO colour-singlet and colour-octet contributions were compared to the data, as were predictions based on the k T-factorisation approach. © 2013 SISSA

Measurement of Beauty Production in Deep Inelastic Scattering at HERA Using Decays into Electrons

© The Author(s) 2011. The production of beauty quarks in ep interactions has been studied with the ZEUS detector at HERA for exchanged four-momentum squared Q2 \u3e 10 GeV2, using an integrated luminosity of 363 pb-1. The beauty events were identified using electrons from semileptonic b decays with a transverse momentum 0.9 \u3c peT \u3c 8 GeV and pseudorapidity |ηe| \u3c 1.5. Cross sections for beauty production were measured and compared with next-to-leadingorder QCD calculations. The beauty contribution to the proton structure function F2 was extracted from the doubledifferential cross section as a function of Bjorken-x and Q2

Measurement of Heavy-quark Jet Photoproduction at HERA

The Author(s) 2011. Photoproduction of beauty and charm quarks in events with at least two jets has been measured with the ZEUS detector at HERA using an integrated luminosity of 133 pb−1. The fractions of jets containing b and c quarks were 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 jet transverse momentum, pjetT, and pseudora pidity, ηjet, were measured. The data are compared with previous measurements and are well described by next-toleading- order QCD predictions