Search

The Large Hadron Collider, designed to collide protons and ions at unprecedented center-of-mass energies, will offer new opportunities for the study of the properties of strongly interacting matter at high energy density and temperature. Such complex investigation will be carried out by three experiments, ALICE, explicitly dedicated to this purpose, ATLAS and CMS, through the analysis of several observables. Among them, an important role is expected to be played by heavy-flavor and heavy quarkonium state measurements. The motivations for measuring open and hidden charm and beauty will be provided in this paper, together with a discussion on the expected performances of the experiments, based on the results of Monte Carlo simulations for a selection of physics channels. [ABSTRACT FROM AUTHOR]

The production of the charmonium states J/ψ, ψ(2S) and χc in proton-nucleus collisions at a center-of-mass energy of 42 GeV is studied using the HERA-B detector. We present J/ψ and ψ′ differential distributions in the ranges: -0.3 < xF < 0.1 and 0 < pT < 4.8 GeV/c. The dependence of the production cross sections on the target nucleus is studied on a data sample obtained by simultaneous use of two different target materials. Preliminary results on production cross sections and cross section ratios for open charm mesons are presented. This paper includes the final result on a search for the FCNC decay D0 → μ+μ-. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The mass distributions of fragments produced by proton-induced fission of 232Th, 235U, 238U, and 237Np at proton energies of 50 and 96 MeV have been measured. The measurements were carried out at The Svedberg Laboratory, Uppsala, Sweden using a high-precision time-of-flight spectrometer for fission fragments and fission neutrons. The measured mass distributions are compared to ones calculated using the TALYS code. Using proton-induced reactions to simulate the outcome of more difficult measurements with neutron beams is discussed. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

In hadron physics, experiments using hadronic probes may shed light on open questions on the structure of hadrons, their interactions that are subject to the strong force and on the symmetries of nature. Therefore a major focus of the physics program studied at the COoler SYnchrotron COSY of the Forschungszentrum Jülich is the production of mesons and hyperons in hadron- hadron scattering with the aim to investigate relevant production processes, interactions of the participating particles as well as symmetries and symmetry breaking. The COoler SYnchrotron COSY at Jülich accelerates protons and deuterons with momenta up to 3.7 GeV/c covering hadron physics in the light quark sector. The availability of the beam cooling systems allow precision measurements, using polarized proton and deuteron beams in combination with polarized Hydrogen or Deuterium targets. Due to the excellent experimental conditions at COSY single- and double-polarization measurements can be performed with high reaction rates. With the operation of the recently installed WASA-at-COSY apparatus, high-statistics studies aiming at rare decays of η and η′ are effectively turning COSY into a meson factory. This contribution summarizes the ongoing physics program at the COSY facility, using the detector systems ANKE, WASA and COSY-TOF highlighting a few selective recent results and outlining future developments. The research at COSY also provides a step towards the realization of FAIR with studies on spin manipulation and polarization build-up of protons in polarized targets. [ABSTRACT FROM AUTHOR]

ALICE is one of the experiments at the LHC. The excellent performance of the detector has been demonstrated with the measurement and analysis of the first proton-proton collisions provided by the LHC on November 2009. We review the first physics results and the general status of the project. We also review the activities of the Mexican group participating in ALICE project. [ABSTRACT FROM AUTHOR]

Low-energy antiprotons are the ideal and perhaps the only tool to study in detail correlated quantum dynamics of few-electron systems in the femto and sub-femtosecond time regime. Unfortunately cooled beams of antiprotons with the necessary beam quality and luminosity are not yet available and cannot be provided with present scientific infrastructures. In order to pave the way for a next-generation low-energy antiproton facility, challenging developments in both, storing and imaging techniques have been launched at MPI-K. A novel ultra-low energy storage ring (USR) to be integrated at the proposed facility for low-energy antiproton and ion research (FLAIR) is being developed to provide electron-cooled beams of antiprotons and possibly highly charged ions in the energy range between 300 and 20 keV/q, maybe even approaching the sub keV regime. To allow for kinematically complete investigations for a variety of different collision processes, a reaction microscope shall be integrated in the ring thus achieving unprecedented luminosities. In this contribution, the present status of experiments in comparison with theory is highlighted and the layout of the USR as well as of the in-ring and an external single-pass reaction microscope is presented. [ABSTRACT FROM AUTHOR]

A new measurement is presented of elastic deeply virtual Compton scattering based on data taken by the H1 detector at HERA. For the first time the cross section dependence is reported on the momentum transfer squared at the proton vertex, t. The data is well described by the QCD based calculations. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

The measurement of azimuthal cross section asymmetries from deeply virtual Compton scattering on the proton and deuteron at HERMES is discussed. In particular results on the longitudinal target spin asymmetry as a function of the azimuthal angle and the Mandelstam t are given. The t-dependence of the asymmetry is compared with calculations based on generalized parton distribution models. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Preliminary results from the H1 experiment on the search for the production of a candidate for the strange pentaquark in the decay channel Θ+ → Ks0p and its antiparticle in the invariant mass combinations of Ks0 mesons with protons and antiprotons in deep-inelastic ep-scattering at HERA are presented. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Excitation functions of proton (natPt(p,xn)191,192,193,194,195,196m,g,196m2,198gAu, natPt(p,x)188,189,191,195mPt, natPt(p,x)188,189,190,192,194mIr), deuteron (natPt(d,xn)192,193,194,195,196m,196Au, natPt(d,x)195m,197Pt, natPt(d,x)192Ir) and alpha induced (natPt(α,xn)192g,193m,193g,195m,195g,197m,197g,199mHg, natPt(α,x)194,195g,196m,196g,198m,198g,199,200m,200gAu, natPt(α,x)195m,197m,197gPt) nuclear reactions on platinum target were measured for the first time. The experimental results were compared with the theoretical calculations using the ALICE-IPPE code. The possible applications of the data are discussed. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Excitation functions of the reactions natIr(p,xn)188,189,191Pt and natIr(p,x)186,187,188,189,190,192Ir were measured up to 70 MeV for practical applications. The measured experimental data were compared with the earlier results and analyzed using theoretical calculations based on the model code Alice-IPPE, The new experimental data show significant deviations from the earlier experimental results. Good agreement was found on average with the model calculation. Applications are also discussed. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]

Two-proton removal in 17Ne at energies from 60 to 710 A MeV in the carbon target is studied in the eikonal approximation of the Glauber model. The excitation of the 15O core fragment is taken into account. The calculated proton removal cross section in 17Ne, the 17Ne and 15O interaction cross sections are compared to the available experimental data. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]