Andrzej Soltan Institute for Nuclear Studies

Otwock, Poland

Andrzej Soltan Institute for Nuclear Studies

Otwock, Poland
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Moszynski M.,Andrzej Soltan Institute for Nuclear Studies
Radiation Measurements | Year: 2010

According to the present knowledge, the non-proportionality of the light yield of scintillators appears to be the fundamental limitation of energy resolution and it is related to the intrinsic properties of the crystals. However, several observations collected in the last 10 years suggest more complex processes in the scintillators. First, the study of undoped NaI and CsI crystals showed that the non-proportionality and energy resolution are very sensitive to the accidental traces of impurities. For some crystals, like CsI(Tl), ZnSe(Te), undoped NaI at liquid nitrogen temperature and finally for NaI(Tl) at temperatures reduced below 0 °C, an influence of slow components of the light pulses on energy resolution and non-proportionality is observed. A common conclusion of these observations is the fact that the highest energy resolution, and particularly the intrinsic resolution measured with scintillators, characterized by two components of the light pulse decay, is obtainable when the spectrometry equipment integrates the whole light of both components. In the limiting case, the afterglow could be considered also as a very slow component destroying the energy resolution. The aim of this work is to summarize all above observations looking for their origin. © 2009 Elsevier Ltd. All rights reserved.


Wibig T.,Andrzej Soltan Institute for Nuclear Studies
Journal of Physics G: Nuclear and Particle Physics | Year: 2010

The LHC measurements above SPS and Tevatron energies give an opportunity to test predictions of the non-extensive thermodynamical picture of hadronic interaction to examine the measured transverse momentum distributions for a newinteraction energy range. We determined the Tsallis model non-extensivity parameter for the hadronization process before short-lived particles decay and distort the initial p⊥ distribution. We have shown that it follows exactly the smooth rise determined at lower energies below the present LHC record. The energy dependence of the q parameter is consistent with expectations and the evidence of the asymptotic limit may be seen. © 2010 IOP Publishing Ltd.


Sobiczewski A.,Andrzej Soltan Institute for Nuclear Studies
Acta Physica Polonica B | Year: 2010

Predictions for the decay chains of the nuclei 293117 and 294117 are done within a macroscopic-microscopic model. The nuclei are planned to be synthesized in the reaction 249Bk + 48Ca (4n and 3n channels), to be performed in Dubna. It is obtained in our study that at least three α decays in both 293117 and 294117 chains should be observed. Thus, at least six new superheavy nuclides and one new superheavy element should be seen, if cross-sections for the reactions are sufficiently large. Additionally, it is expected that the decay chain of 294117 would be the first one in which the isotope of the element 113, 286113, has a chance to be studied chemically.


Sobiczewski A.,Andrzej Soltan Institute for Nuclear Studies
Radiochimica Acta | Year: 2011

A short review of the studies of superheavy nuclei (SHN), done recently in our theoretical group of Warsaw, is presented. Main attention is given to description of the properties of SHN. The description is performed by macroscopic-microscopic methods. Such properties as mass, α-decay energy and α-decay half-life are considered. Special attention is devoted to the analysis of the half-life. Although mainly treated in a phenomenological way, the role of the microscopic structure of a nucleus in this quantity is tested. It is found that this structure may significantly change the half-life of nuclei with the odd nucleon (or nucleons). © by Oldenbourg Wissenschaftsverlag, München.


Wycech S.,Andrzej Soltan Institute for Nuclear Studies
Acta Physica Polonica B | Year: 2010

The nuclear states of K̄ and η are bound by a similar mechanism - the excitations of nucleons to Λ(1405) and N*(1535) resonant states. The observed large differences in binding energies are understood in terms of separation of the involved energies and the resonance positions. The other experimental findings: broad K̄-mesic and narrow η-mesic states are more difficult to understand. A phenomenological model for η-N interactions is used to explain the suppression of the η absorption in light nuclei.


Kielczewska D.,Andrzej Soltan Institute for Nuclear Studies
Acta Physica Polonica B | Year: 2010

The Tokai to Kamioka (T2K) is the second generation long baseline neutrino oscillation experiment. Its primary goal is to measure the last unknown mixing angle θ13 and determine precisely the value of Δm 23 2 θ23 oscillation parameters. The neutrino beam from J-PARC high intensity proton synchrotron travels 295 km to Super-Kamiokande detector. The status of the project and its expected physics results are presented.


Smolanczuk R.,Andrzej Soltan Institute for Nuclear Studies
Physical Review C - Nuclear Physics | Year: 2010

Chances of synthesis of transactinide nuclei in cold fusion reactions (one-neutron-out reactions) using radioactive beams are evaluated. Because in most of the cases intensities of radioactive beams are significantly less than those of the stable beams, reactions with the greatest radioactive-beam intensities for the particular elements are considered. The results are compared with the recent ones obtained by Loveland [Phys. Rev. CPRVCAN0556-281310.1103/ PhysRevC.76.014612 76, 014612 (2007)], who investigated the same nuclei. © 2010 The American Physical Society.


Wibig T.,Andrzej Soltan Institute for Nuclear Studies
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

The pseudorapidity measurements at LHC, although in the central region only, allows us to perform preliminary tests of the multiparticle production extrapolation formula inspired by the analysis of recent cosmic ray data. Feynman scaling violation in the form proposed originally by Wdowczyk and Wolfendale in the 1970s has been applied to the Pierre Auger Observatory and the Hi-Res group measurements. The consistency of the average extensive air shower development with the hypothesis of protons being the primary particles, as indicated by anisotropy observations, was found for a smooth rise of the scaling violation parameter. We have shown that the longitudinal momenta of the produced particles determined inclusively as rapidity (pseudorapidity) distributions measured by LHC experiments follow the same universal high energy distribution scaled respectively. The high degree of Feynman scaling violation is confirmed. The decrease of the very high energy interaction inelasticity suggested by the cosmic ray data analysis is found to be consistent with LHC measurements up to 7 TeV. © 2011 Elsevier B.V.


Sobiczewski A.,Andrzej Soltan Institute for Nuclear Studies
Acta Physica Polonica B | Year: 2011

Predictions are made for the decay chains of the nuclei 298120 and 299120, i.e. for two isotopes of the not-yet-observed superheavy element 120. These nuclei are planned to be synthesized in the nuclear reaction 54Cr + 248Cm, in an experiment to be performed in Darmstadt (Germany). We predict that at least four decays in both the 298120 and 299120 chains should be observed. This means that at least six new superheavy nuclides and one new superheavy element (120) should be seen, if the cross section for the reaction is sufficiently large. The predicted half-lives: 11 μs and 15 μs for the nuclei 298120 and 299120, respectively, indicate that we are not far from the lower limit of the half-life (about 1 μs) for a nucleus to be observable. Due to this, the planned experiment will be an important step towards answering the essential question: where is the limit of the periodic table of the elements?.


Bialkowska H.,Andrzej Soltan Institute for Nuclear Studies
Acta Physica Polonica B | Year: 2011

The observation of long range near side angular correlation (the socalled ridge effect) in pp collisions at the LHC is presented. Data on such correlations in heavy ion collisions at RHIC are shown. Previous informations on angular correlations in high energy pp collisions are critically reviewed. A spectrum of many recent interpretations concerning the effect is presented.

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