371 research outputs found

    Transformacije temperature u relativističkoj termodinamici

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    We analyse the problem of temperature transformation from a historical perspective and attempt to give an answer to the question: "Is the temperature of an object in relativistic motion lower, higher or the same with respect to that of the same object at rest?\u27\u27. We conclude that such a question is ill posed and has no unique answer. We are not claiming a comprehensive review of the subject. In the historical discussion, we give special emphasis to the contribution on the subject by Professor Blanu sa from Zagreb.Analiziramo problem transformacije temperature s povijesnog stajališta i pokušavamo odgovoriti na pitanje: “Da li je temperatura tijela koje se giba relativističkom brzinom niža, viša ili jednaka onoj u sustavu tijela?” Naš je zaključak da je to pitanje pogrešno postavljeno i nema jedan odgovor. Ne tvrdimo da je naše razmatranje cjelovito. U povijesnom odsječku posebno naglašavamo doprinos Profesora D. Blanuše o toj temi

    Erraticity of Rapidity Gaps

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    The use of rapidity gaps is proposed as a measure of the spatial pattern of an event. When the event multiplicity is low, the gaps between neighboring particles carry far more information about an event than multiplicity spikes, which may occur very rarely. Two moments of the gap distrubiton are suggested for characterizing an event. The fluctuations of those moments from event to event are then quantified by an entropy-like measure, which serves to describe erraticity. We use ECOMB to simulate the exclusive rapidity distribution of each event, from which the erraticity measures are calculated. The dependences of those measures on the order of qq of the moments provide single-parameter characterizations of erraticity.Comment: 10 pages LaTeX + 5 figures p

    Reply to Comment of Gazdzicki and Heinz on Strangeness Enhancement in p+Ap+A and S+AS+A

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    The Comment of Gazdzicki and Heinz is flawed because their assumed baryon stopping power in pApA is inconsistent with data and because they ignored half the analysis based on the VENUS model. The Comment continues the misleading presentation of strangeness enhancement by focusing on ratios of integrated yields. Those ratios discard essential experimental information on the rapidity dependence of produced Λ\Lambda and obscure discrepancies between different data sets. Our conclusion remains that the NA35 minimum bias data on p+SΛ+Xp+S\rightarrow\Lambda +X indicate an anomalous enhancement of central rapidity strangeness in few nucleon reactions that points to non-equilibrium dynamics as responsible for strangeness enhancement in nuclear reactions.Comment: revtex file, 6 pages, submitted to Phys. Rev.

    Intermittency for coherent and incoherent current ensemble model

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    We investigate the origin of intermittency for multiparticle distribution in momentum space, following the idea that there is a kind of power law distribution of the space-time region of hadron emission. Using the formalism of current ensamble model to describe boson sources we discuss intermittency exponents for the coherent and incoherent ( chaotic) particle production scheme.Comment: 13 pages, latex, no figure

    Factorial Moments of Continuous Order

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    The normalized factorial moments FqF_q are continued to noninteger values of the order qq, satisfying the condition that the statistical fluctuations remain filtered out. That is, for Poisson distribution Fq=1F_q = 1 for all qq. The continuation procedure is designed with phenomenology and data analysis in mind. Examples are given to show how FqF_q can be obtained for positive and negative values of qq. With qq being continuous, multifractal analysis is made possible for multiplicity distributions that arise from self-similar dynamics. A step-by-step procedure of the method is summarized in the conclusion.Comment: 15 pages + 9 figures (figures available upon request), Late

    Mass Suppression in Octet Baryon Production

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    There is a striking suppression of the cross section for production of octet baryons in e+ee^+ e ^- annihilation, as the mass of the produced hadron increases. We present a simple parametrization for the fragmentation functions into octet baryons guided by two input models: the SU(3) flavor symmetry part is given by a quark-diquark model, and the baryon mass suppression part is inspired by the string model. We need only eight free parameters to describe the fragmentation functions for all octet baryons. These free parameters are determined by a fit to the experimental data of octet baryon production in e+ee^+ e ^- annihilation. Then we apply the obtained fragmentation functions to predict the cross section of the octet baryon production in charged lepton DIS and find consistency with the available experimental data. Furthermore, baryon production in pppp collisions is suggested to be an ideal domain to check the predicted mass suppression.Comment: 20 pages, 5 figure

    Photoproduction of ϱo on hydrogen with tagged photons between 4 and 6 GeV

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    We have measured the reaction γp → pπ+π− in the DESY 1 m Streamer Chamber. The dominant ϱo production is analyzed in terms of various models

    Charged Particle Production in Proton-, Deuteron-, Oxygen- and Sulphur-Nucleus Collisions at 200 GeV per Nucleon

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    The transverse momentum and rapidity distributions of net protons and negatively charged hadrons have been measured for minimum bias proton-nucleus and deuteron-gold interactions, as well as central oxygen-gold and sulphur-nucleus collisions at 200 GeV per nucleon. The rapidity density of net protons at midrapidity in central nucleus-nucleus collisions increases both with target mass for sulphur projectiles and with the projectile mass for a gold target. The shape of the rapidity distributions of net protons forward of midrapidity for d+Au and central S+Au collisions is similar. The average rapidity loss is larger than 2 units of rapidity for reactions with the gold target. The transverse momentum spectra of net protons for all reactions can be described by a thermal distribution with `temperatures' between 145 +- 11 MeV (p+S interactions) and 244 +- 43 MeV (central S+Au collisions). The multiplicity of negatively charged hadrons increases with the mass of the colliding system. The shape of the transverse momentum spectra of negatively charged hadrons changes from minimum bias p+p and p+S interactions to p+Au and central nucleus-nucleus collisions. The mean transverse momentum is almost constant in the vicinity of midrapidity and shows little variation with the target and projectile masses. The average number of produced negatively charged hadrons per participant baryon increases slightly from p+p, p+A to central S+S,Ag collisions.Comment: 47 pages, submitted to Z. Phys.

    Lambda and Antilambda polarization from deep inelastic muon scattering

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    We report results of the first measurements of Lambda and Antilambda polarization produced in deep inelastic polarized muon scattering on the nucleon. The results are consistent with an expected trend towards positive polarization with increasing x_F. The polarizations of Lambda and Antilambda appear to have opposite signs. A large negative polarization for Lambda at low positive x_F is observed and is not explained by existing models.A possible interpretation is presented.Comment: 9 pages, 2 figure
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