Bose-Einstein correlations in one and two dimensions in deep inelastic scattering

Bose-Einstein correlations in one and two dimensions have been studied in deep inelastic ep scattering events measured with the ZEUS detector at HERA using an integrated luminosity of 121 pb-1. The correlations are independent of the virtuality of the exchanged photon, Q2, in the range 0.1 < Q2 < 8000 GeV2. There is no significant difference between the correlations in the current and target regions of the Breit frame for Q2 > 100 GeV2. The two-dimensional shape of the particle-production source was investigated, and a significant difference between the transverse and the longitudinal dimensions of the source is observed. This difference also shows no Q2 dependence. The results demonstrate that Bose-Einstein interference, and hence the size of the particle-production source, is insensitive to the hard subprocess. © 2004 Published by Elsevier B.V

The JEM-EUSO mission to explore the extreme Universe

The JEM-EUSO mission explores the origin of the extreme energy comic-rays (EECRs) above 1020 eV and challenges to the limit of the basic physics, through the observations, of their arrival directions and energies. It is designed to observe more than 1,000 events of EECRs above 7×10 19 eV in its five-year operation with an exposure larger than 1 million km2 · sr · year. The super-wide-field (60 degrees) telescope with a diameter of about 2.5m looks down the atmosphere of the night-side of the earth to detect near UV photons (330-400nm, both fluorescent and Cherenkov photons) emitted from the giant air-shower produced by an EECR. The arrival direction map with 1,000 events naturally tells us the origin of the EECRs and allows us to identify the EECR sources to known astronomical objects. The comparison among the energy spectra of the spatially resolved individual sources will clarify the acceleration/emission mechanism, and also finally confirm the Greisen-Zatse'pin-Kuzmin process for the validation of Lorentz invariance up to γ∼1011. Neutral components (neutrinos and gamma rays) can also be detected as well, if their fluxes are high enough. The JEM-EUSO mission is planned to be launched by a H2B rocket about 2015 and transferred to ISS by H2 Transfer Vehicle (HTV). It will be attached to the external experiment platform of "KIBO" which completed July 2009 by STS-127 mission of the space shuttle. The first flight of HTV by H2B rocket was successfully done in September and October 2009. © 2010 American Institute of Physics.Grand Accelerateur National d'Ions Lourds (GANIL);Helmholtzzentrum fur Schwerionenforschung GmbH (GSI);Riken Nishina Center for Accelerator-Based Science (RIKEN);Universite libre de Bruxelles (ULB);French-Japanese International Associated Laboratory;Inamori Foundatio

Measurement of event shapes in deep inelastic scattering at HERA

Inclusive event-shape variables have been measured in the current region of the Breit frame for neutral current deep inelastic ep scattering using an integrated luminosity of 45.0 pb-1 collected with the ZEUS detector at HERA. The variables studied included thrust, jet broadening and invariant jet mass. The kinematic range covered was 10 < Q2 < 20480 GeV2 and 6 × 10-4 < x < 0.6, where Q2 is the virtuality of the exchanged boson and x is the Bjorken variable. The Q dependence of the shape variables has been used in conjunction with NLO perturbative calculations and the Dokshitzer-Webber non-perturbative corrections ('power corrections') to investigate the validity of this approach

Dijet angular distributions in photoproduction of charm at HERA

Dijet angular distributions of photoproduction events in which a D*± meson is produced in association with one of two energetic jets have been measured with the ZEUS detector at HERA, using an integrated luminosity of 120 pb-1. Differential cross sections as a function of the angle between the charm-jet and the proton-beam direction in the dijet rest frame have been measured for samples enriched in direct or resolved photon events. The results are compared with predictions from leading-order parton-shower Monte Carlo models and with next-to-leading-order QCD calculations. The angular distributions show clear evidence for the existence of charm originating from the photon. © 2003 Published by Elsevier B.V

Dissociation of virtual photons in events with a leading proton at HERA

The ZEUS detector has been used to study dissociation of virtual photons in events with a leading proton, γ*p → Xp, in e +p collisions at HERA. The data cover photon virtualities in two ranges, 0.03 < Q 2 < 0.60 GeV 2 and 2 < Q 2 < 100 GeV 2, with M X > 1.5 GeV, where M X is the mass of the hadronic final state, X. Events were required to have a leading proton, detected in the ZEUS leading proton spectrometer, carrying at least 90% of the incoming proton energy. The cross section is presented as a function of t, the squared four-momentum transfer at the proton vertex, Φ, the azimuthal angle between the positron scattering plane and the proton scattering plane, and Q 2. The data are presented in terms of the diffractive structure function, F 2 D(3). A next-to-leading-order QCD fit to the higher-Q 2 data set and to previously published diffractive charm production data is presented. © Springer-Verlag/Società Italiana di Fisica 2004

Preparation of the TUS space experiment for UHECR study

We report on the current status of the TUS space mission project: its goals and the progress achieved so far. The Fresnel mirrors design, performed checks and their production are discussed. Also we discuss our future plans including auxiliary analysis of the fluorescence light yield measured this year by LAPP (Annecy), JINR (Dubna) and LIP (Lisbon) MACFLY Collaboration. © World Scientific Publishing Company

Status of the space experiment TUS for UHECR study

Bhabha Atomic Research Centre (BARC);et al.;Inter-University Centre for Astronomy and Astrophysics (IUCAA);National Centre for Radio Astrophysics (NCRA);Tata Institute of Fundamental Research (TIFR);University of Pun

Measurement of deeply virtual Compton scattering at HERA

The cross-section for deeply virtual Compton scattering in the reaction ep → eγp has been measured with the ZEUS detector at HERA using integrated luminosities of 95.0 pb-1 of e+p and 16.7 pb-1 of e-p collisions. Differential cross-sections are presented as a function of the exchanged-photon virtuality, Q2, and the centre-of-mass energy, W, of the γ*p system in the region 5 < Q2 < 100 GeV2 and 40 < W < 140 GeV. The measured cross-sections rise steeply with increasing W. The measurements are compared to QCD-based calculations. © 2003 Elsevier B.V. All rights reserved

Ultra-fast flash observatory for observation of early photons from gamma ray bursts

We describe the space project of Ultra-Fast Flash Observatory (UFFO) which will observe early optical photons from gamma-ray bursts (GRBs) with a sub-second optical response, for the first time. The UFFO will probe the early optical rise of GRBs, opening a completely new frontier in GRB and transient studies, using a fast response Slewing Mirror Telescope (SMT) that redirects optical path to telescope instead of slewing of telescopes or spacecraft. In our small UFFO-Pathfinder experiment, scheduled to launch aboard the Lomonosov satellite in 2012, we use a motorized mirror in our Slewing Mirror Telescope instrument to achieve less than one second optical response after X-ray trigger. We describe the science and the mission of the UFFO project, including a next version called UFFO-100. With our program of ultra-fast optical response GRB observatories, we aim to gain a deeper understanding of GRB mechanisms, and potentially open up the z>10 universe to study via GRB as point source emission probes. © 2012 SPIE.The Society of Photo-Optical Instrumentation Engineers (SPIE