National Center for Nuclear Studies

Warsaw, Poland

National Center for Nuclear Studies

Warsaw, Poland
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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.


Zdunek K.,Warsaw University of Technology | Zdunek K.,National Center for Nuclear Studies | Nowakowska-Langier K.,National Center for Nuclear Studies | Dora J.,Dora Power Systems | Chodun R.,Warsaw University of Technology
Surface and Coatings Technology | Year: 2013

The paper describes the effects of utilizing pulse valves for dosing a plasma forming gas supplied directly to the plasma source. The concept of exploiting such valves as actual controllers of the plasma process replacing the ignitrons-spark switch valves used up to now has been practically verified in the technology of TiN layers manufactured by impulse plasma deposition (IPD) method. The TiN layers manufactured at modified plasma pulse generation conditions on unheated cutting tools made it possible to increase the cutting lifetime by a factor of up to twenty. The interpretation suggests that this increase is likely to result from lower energy dissipation for intermolecular collisions because of an increased mean free path. On the basis of positive results of research related to IPD method, the method of plasma excitation through an injection of plasma-forming gas has been applied in conditions of magnetron sputtering (gas injection magnetron sputtering, GIMS). GIMS applied as a material source with a single magnetron has been used for formation of AlN layers on silicon substrates. Electronic examination of MIS structures with such thin AlN layer demonstrated potentially advantageous structural properties of such layers in the context of their application in the design of electronic devices, e.g. as gate insulator layers. © 2012 Elsevier B.V.


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.


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.


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.


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.


Ukleja A.,National Center for Nuclear Studies
Journal of Physics: Conference Series | Year: 2013

In pp collisions at the LHC the LHCb experiment has collected the world's largest sample of charmed hadrons. Using data of an integrated luminosity of 1.0 fb-1 recorded in 2011 a measurement of direct and indirect CP violation in the charm sector and of D0 mixing parameters was performed. Results from several decay modes are presented with complementary time-dependent and time-integrated analyses. © Published under licence by IOP Publishing Ltd.


Wycech S.,National Center for Nuclear Studies
Hyperfine Interactions | Year: 2012

Studies of Λ (1405) in Σπ decay channels are briefly presented and the related uncertainties indicated. The advantages of measurements in the K̄N channel are stressed. Two methods: studies of upper levels in K-mesic atoms and radiative decays from the hydrogen atom to Λ (1405) are discussed. © 2012 Springer Science+Business Media B.V.


Rozynek J.,National Center for Nuclear Studies
EPJ Web of Conferences | Year: 2015

It is shown how nonextensive Nambu-Jona-Lasinio (NJL) calculations in the critical region in the vicinity of phase transition to quark matter allow to determine a nonextensive parameter q from a specific heat capacity Cq. © Owned by the authors, published by EDP Sciences, 2015.


Rozynek J.,National Center for Nuclear Studies
EPJ Web of Conferences | Year: 2015

Even small departures from a nuclear equilibrium density with constant nucleon masses require an increase of a nucleon enthalpy. This process can be described as volume corrections to a nucleon rest energy, which are proportional to pressure and absent in a standard Relativistic Mean Field (RMF) with point-like nucleons. Bag model and RMF calculations show the modifications of nucleon mass, nucleon radius and a Parton Distribution Function (PDF) of Nuclear Matter (NM) above the saturation point originated from the pressure correction. © Owned by the authors, published by EDP Sciences, 2015.

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