Experimental study of the space-time development of the particle production process in hadron-nucleon collisions, using massive target nucleus as a detector

Experimental study of the space-time development of the particle production process in hadronic collisions at its initial stage was performed. Massive target nuclei have been used as fine detectors of properties of the particle production process development within time intervals smaller than 10 to the 22nd power s and spatial distances smaller than 10 to the 12th power cm. In hadron-nucleon collisions, in particular in nucleon-nucleon collisions, the particle production process goes through intermediate objects in 2 yields 2 type endoergic reactions. The objects decay into commonly observed resonances and paricles

Experimental evidence of the decrease of kinetic energy of hadrons in passing through atomic nuclei

Hadrons with kinetic energies higher than the pion production threshold lose their kinetic energies monotonically in traversing atomic nuclei, due to the strong interactions in nuclear matter. This phenomenon is a crude analogy to the energy loss of charged particles in their passage through materials. Experimental evidence is presented

Physical meaning of the multiplicities of emitted nucleons in hadron-nucleus collisions

The analysis of experimental data on hadron-nucleus collisions at energies from about 2 up to about 400 GeV was performed in order to discover a physical meaning of the multiplicity of emitted nucleons. Simple relations between the multiplicities and the thickness of the nuclear matter layer involved in collisions were obtained

Experimental basis for the models of cascade propagation in atmosphere

The picture of the hadron nucleus collision process is presented as it emerges on the basis of newly obtained experimental data. The picture is applicable to models of cascade propagation in Earth atmosphere

Scattering and stopping of hadrons in nuclear matter

It was observed, in the 180 litre xenon bubble chamber, that when hadrons with kinetic energy higher than the pion production threshold fall on a layer of nuclear matter - on an atomic nucleus in other words - in many cases they can pass through it without causing particles production but they are deflected through some deflection angles; if the energy is lower than a few GeV and the nuclear matter layer is thick enough, the hadrons can be stopped in it. The amount of the deflection at a given incident hadron energy varies with the way the hadron strikes the atomic nucleus; the probability of the occurrence of stopping depends on the incident hadron identity and energy, and on the way the hadron passed through the nucleus, as well

Measurements of hadron mean free path for the particle-producing collisions in nuclear matter

It is not obvious a priority that the cross-section for a process in hadron collisions with free nucleons is the same as that for the process in hadron collisions with nucleons inside a target nucleus. The question arises: what is the cross-section for a process in a hadron collision with nucleon on inside the atomic nucleus. The answer to it must be found in experiments. The mean free path for particle-producing collisions of pions in nuclear matter is determined experimentally using pion-xenon nucleus collisions at 3.5 GeV/c momentum. Relation between the mean free path in question lambda sub in nucleons fm squared and the cross-section in units of fm squared/nucleon for collisions of the hadron with free nucleon is: lambda sub i = k/cross section sub i, where k = 3.00 plus or minus 0.26

Energy-range relations for hadrons in nuclear matter

Range-energy relations for hadrons in nuclear matter exist similarly to the range-energy relations for charged particles in materials. When hadrons of GeV kinetic energies collide with atomic nuclei massive enough, events occur in which incident hadron is stopped completely inside the target nucleus without causing particle production - without pion production in particular. The stoppings are always accompanied by intensive emission of nucleons with kinetic energy from about 20 up to about 400 MeV. It was shown experimentally that the mean number of the emitted nucleons is a measure of the mean path in nuclear matter in nucleons on which the incident hadrons are stopped

How are particle production, nucleon emission and target fragment evaporation processes interrelated in hadron-nucleus collisions?

Relations between particle production, nucleon emission, and fragment evaporation processes were searched for in hadron-nucleus collisions. It was stated that: (1) the nucleon emission and target fragment evaporation proceed independently of the particle production process; and (2) relation between multiplicities of the emitted protons and of the evaporated charged fragments is expressed by simple formula

Search for the radiative decay η→π0γγ\eta \to \pi^0 \gamma \gamma in the SND experiment at VEPP-2M

The $\eta \to \pi^0 \gamma \gamma$ decay was investigated by the SND detector at VEPP-2M $e^+e^-$ collider in the reaction $e^+e^-\to\phi\to \eta\gamma$. Here we present the results and some details of this study. We report an upper limit (90% c.l.) $Br(\eta \to \pi^0 \gamma \gamma)<8.4\times 10^{-4}$ as our final result. Our upper limit does not contradict the earlier measurement by GAMS spectrometer. To facilitate future studies a rather detailed review of the problem is also given.Comment: 24 pages, 6 figures, LaTex. To be published in Nucl. Phys.

Dualizm środków zaskarżenia wadliwych uchwał wspólników w spółce z ograniczoną odpowiedzialnością

The article deals with the problem of dualism of means of challenging defective shareholder resolutions in a limited liability company. The overall objective of the article is to compare legal effects of the action to declare the invalidity of a resolution with action for its revoking. Therefore, it is needed to look deeper into defectiveness of the legal act regulations. The main conclusion of the legal discussion is that our domestic regulations (Art. 249 and 252 Polish Commercial Companies Code) provide two separate actions which have identical legal effects.Niniejszy artykuł dotyczy dualizmu regulacji Kodeksu spółek handlowych w zakresie możliwości zaskarżenia wadliwych uchwał wspólników sp. z o.o. Z uwagi na specyfikę przedmiotu rozważań, konieczne okazało się bliższe spojrzenie na regulacje dotyczące sankcji wadliwości czynności prawnych w kontekście prawa prywatnego. Następnie, pogłębionej analizie poddane zostały dwa zasadnicze powództwa służące wyeliminowaniu z obrotu prawnego wadliwych uchwał wspólników sp. z o.o., a więc powództwo o stwierdzenie nieważności uchwały oraz powództwo o jej uchylenie. Konkluzje przeprowadzonych rozważań prowadzą do wniosku, że pomimo odrębności terminologicznej użytej przez prawodawcę, oba powództwa cechują się zbieżną konstrukcją skutków prawnych ich uwzględnienia