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Kazana M.,National Center for Nuclear Studies
EPJ Web of Conferences | Year: 2014

Signs of physics beyond the Standard Model are widely searched for in proton-proton collisions at the Large Hadron Collider (LHC). We review results of exotic physics searches based on 20 fb-1 of data collected in 2012 by the Compact Muon Solenoid (CMS) detector at a center-of-mass energy of 8 TeV. Selected benchmark analyses are presented, including searches in topologies with leptons, photons and jets, as well as a description of techniques to identify the production of exotic objects such as massive long-lived charged particles. No statistically-significant excess of events is observed in the data, therefore results are presented in terms of exclusion limits on the mass and the production cross section of hypothetical particles. © Owned by the authors, published by EDP Sciences, 2014. Source

Wycech S.,National Center for Nuclear Studies
Journal of Physics: Conference Series | Year: 2012

The search for deeply bound nuclear states of K̄ mesons is presented and the main experimental and theoretical uncertainties are briefly discussed. The need for new experiments is stressed and some atomic experiments are suggested. The involved physics is illustrated on a simple fixed nucleon model which becomes a basis for variational calculations. Source

Friedman E.,Hebrew University of Jerusalem | Gal A.,Hebrew University of Jerusalem | Loiseau B.,University Pierre and Marie Curie | Wycech S.,National Center for Nuclear Studies
Nuclear Physics A | Year: 2015

A general algorithm for handling the energy dependence of hadron-nucleon amplitudes in the nuclear medium, consistently with their density dependence, has been recently applied to antikaons, eta mesons and pions interacting with nuclei. Here we apply this approach to antiprotons below threshold, analyzing experimental results for antiprotonic atoms across the periodic table. It is also applied to antiproton and antineutron interactions with nuclei up to 400 MeV/c, comparing with elastic scattering and annihilation cross sections. The underlying p-N scattering amplitudes are derived from the Paris N-N potential, including in-medium modifications. Emphasis is placed on the role of the P-wave amplitudes with respect to the repulsive S-wave amplitudes. © 2015 Elsevier B.V. Source

Wycech S.,National Center for Nuclear Studies | Krzemien W.,Jagiellonian University
Acta Physica Polonica B | Year: 2014

Collisions in a system of two particles at energies close to a bound state in different channels are discussed. Next, the bound state decays into a third coupled channel. A phenomenological approach to dd → π-p 3He reaction is presented. Source

Augustyniak W.,National Center for Nuclear Studies
Nuclear Physics B - Proceedings Supplements | Year: 2013

Exclusive electroproduction of vector mesons has been measured on hydrogen and deuterium targets at HERMES using the 27.6 GeV electron/positron beam of HERA. From this process, information can be obtained about generalized parton distributions (GPDs), which provide a unified description of the structure of hadrons embedding longitudinal-momentum distributions (ordinary PDFs) and transverse-position information (form factors). The study of the azimuthal distribution of the decay products via spin-density matrix elements provide constraints on helicity-amplitudes used to describe exclusive vector-meson production. Recent results from the HERMES experiment on the production of ρ0, ω and φ vector mesons will be presented. © 2013 Elsevier B.V. Source

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