We analyzed the identified hadron multiplicity predictions of the modified thermodynamical model of the multiparticle production processes with non-extensive statistic. The replacement of the ...standard Boltzmann exponential factor by the eventually much more slowly falling Tsallis one is suggested by the analysis of the transverse momentum distributions measured at high energies. The increase of high transverse momenta should accord with the abundance of heavy secondary particles, in particular multistrange baryons. The introduction to the thermodynamical model of suppression factors similar to the ones in quark jet fragmentation models is discussed.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The recent measurements of the elastic cross section by the TOTEM Collaboration together with the first estimations of the inelastic cross sections by other LHC detectors are used to test the ...simplest version of the geometrical model of the proton-proton scattering. We show that the description found for lower energy data, with the modest adjustment of the model parameter extrapolation, could be, in principle, used to describe the LHC measurement and to predict the cross sections in very high energy cosmic ray domain. However, the shape of the first elastic dip in the elastic differential scattering cross section suggests that the ratio of the real to the imaginary part of the elastic amplitude falls rather fast and the analysis of the elastic cross-section fraction suggests that the geometrical picture and scaling of the proton-proton collision should be modified when entering the ultrahigh-energy domain.
We have updated our analysis of some nine years ago in which we drew attention to the presence of a finite ‘cosmic ray foreground’ to the then available map of the cosmic microwave background (CMB). ...The analysis has been repeated with the most recent nine-year data. We argue that the foreground has been reduced but not to zero. Specifically, there are still features which relate to Galactic phenomena, in particular, the presence of a cosmic ray/CMB intensity correlation in Hydrogen gas ‘chimneys’ and symmetries with respect to the Galactic plane. However, the region of space examined by the BICEP2 group show no significant correlations.
We present the purpose, long-term development vision, basic design, detection algorithm and preliminary results obtained with the Cosmic Ray Extremely Distributed Observatory (CREDO) Detector mobile ...application. The CREDO Detector app and related infrastructure are unique in terms of their scale, targeting many form-factors and open-access philosophy. This philosophy translates to the open-source code of the app, open-access in terms of both data inflow as well as data consumption and above all, the citizen science philosophy that means that the infrastructure is open to all who wish to participate in the project. The CREDO infrastructure and CREDO Detector app are designed for the large-scale study of various radiation forms that continuously reach the Earth from space, but with the sensitivity to local radioactivity as well. Such study has great significance both scientifically and educationally as cosmic radiation has an impact on diverse research areas from life on Earth to the functioning of modern electronic devices. The CREDO Detector app is now working worldwide across phones, tablets, laptops, PCs and cheap dedicated registration stations. These diverse measurements contribute to the broader search for large-scale cosmic ray correlations, as well as the CREDO-specific proposed extensive air showers and incoherent secondary cosmic rays.
The origin of the prominent 'knee' in the cosmic ray energy spectrum at an energy of several PeV is still uncertain. A recent mechanism has shown promise, however; this involves particles from a very ...young pulsar interacting with the radiation field from its associated very young supernova remnant. The ensuing nuclear reaction of the particles with the photons by way of e super(+ e) super(-) production then causes the characteristic knee. In an earlier paper we argued that the mechanism would imply only one source of a very rare type - if it were to explain the spectral shape. Here we examine the mechanism in more detail and conclude that for even a single source to work its characteristics would need to be so unusual that the mechanism would not be possible for any known type of pulsarsupernova combination.
Recent results from the Pierre Auger Observatory and the Hi-Res array have been analysed hoping to derive a strong statement about the mass composition in the region of the ankle, where the change ...from Galactic to ExtraGalactic cosmic ray flux should take place, at least according to some theoretical predictions. It is shown that there are problems in reconciling the data with expectation.
A detailed search has been made for evidence of residual foreground contributions to the cosmic microwave background (CMB) in the map generated by the Wilkinson Microwave Anisotropy Probe (WMAP), a ...map that has been (nominally) cleaned for the foreground already. We find positive results in that various features relate to Galactic properties. For example, on the largest angular scales we find significant differences between the power in the fluctuations for positive and negative Galactic latitudes and between the four Galactic quadrants. There are also differences between the power spectrum at latitudes within 10° of the plane and at higher latitudes. The mean temperature shows similar variations. An explanation in terms of Galactic effects seems inescapable. In an effort to find the origin of these Galactic-style effects we have examined evidence from Galactic gamma-rays, specifically from the EGRET instrument. We are mindful that the CMB maps examined have already been ‘cleaned’ (for CR and other effects) in a rather complex way, but, in our view, the cleaning has left some potentially serious ‘contaminations’. A correlation is found between gamma-ray intensities and the CMB and other CR indicators. For example, regions of the Galaxy having (line-of-sight) steep CR energy spectra have low mean CMB temperatures, and the important Loop I edge region, where the CR intensity is high, has a high mean temperature. Most of the large-scale Galactic asymmetries (e.g. north–south difference and quadrant variations) have analogues in CR asymmetries and also in some other Galactic properties, such as the column density of gas. Thus, it is possible to hypothesize about direct CR-induced contributions, although it may be that CRs are simply the indicators of Galactic ‘conditions’ which are influencing the residual CMB fluctuations. Irrespective of the actual cause of the correlations we have endeavoured to extrapolate to the situation where the residual foreground is minimized. The effect on the usually derived cosmological properties is briefly examined. The least that can be said is that the ‘error’ in some of these properties has been underestimated.
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