111 research outputs found
On model-independent analyses of elastic hadron scattering
By means of an almost model-independent parametrization for the elastic hadron-hadron amplitude, as a function of the energy and the momentum transfer, we obtain good descriptions of the physical quantities that characterize elastic proton-proton and antiproton-proton scattering (total cross section, r parameter and differential cross section). The parametrization is inferred on empirical grounds and selected according to high energy theorems and limits from axiomatic quantum field theory. Based on the predictive character of the approach we present predictions for the above physical quantities at the Brookhaven RHIC, Fermilab Tevatron and CERN LHC energies.67567
Regge Analysis Of Diffractive And Leading Baryon Structure Functions From Deep Inelastic Scattering
In this paper we present a combined analysis of the H1 data on leading baryon and diffractive structure functions from DIS, which are handled as two components of the same semi-inclusive process. The available structure function data are analyzed in a series of fits in which three main exchanges are taken into account: the Pomeron, Reggeon, and pion. For each of these contributions, Regge factorization of the correspondent structure function is assumed. By this procedure, we extract information about the interface between the diffractive, Pomeron-dominated, region and the leading proton spectrum, which is mostly ruled by secondary exchanges. One of the main results is that the relative Reggeon contribution to the semi-inclusive structure function is much smaller than the one obtained from an analysis of the diffractive structure function alone.659 B9600619600610Ahmed, T., (1995) Phys. Lett. B, 348, p. 681Derrick, M., (1995) Z. Phys. C, 68, p. 569Adloff, C., (1999) Eur. Phys. J. C, 6, p. 587Cartiglia, N., hep-ph/9706416http://www-zeus.desy.de/publications.php3Collins, P.D.B., (1977) An Introduction to Regge Theory and High Energy Physics, , Cambridge University Press, Cambridge, EnglandBatista, M., Covolan, R.J.M., (1999) Phys. Rev. D, 59, p. 054006Szczurek, A., Nikolaev, N.N., Speth, J., (1998) Phys. Lett. B, 428, p. 383Adloff, C., (1997) Z. Phys. C, 76, p. 613Breitweg, J., (1998) Eur. Phys. J. C, 1, p. 81Ingelman, G., Schlein, P., (1985) Phys. Lett., 152 B, p. 256Covolan, R.J.M., Soares, M.S., (1998) Phys. Rev. D, 57, p. 180Alvero, L., (1999) Phys. Rev. D, 59, p. 074022McDermott, M.F., Briskin, G., (1996) Proceedings of the Workshop "Future Physics at HERA", , edited by G. Ingelman, A. De Roeck, and R. Klanner, DESY, Hamburg, hep-ph/9610245Covolan, R.J.M., Soares, M.S., (1999) Phys. Rev. D, 60, p. 054005Covolan, R.J.M., Soares, M.S., (2000) Phys. Rev. D, 61, pp. 019901EGolec-Biemat, K., Kwieciński, J., Szczurek, A., (1997) Phys. Rev. D, 56, p. 3955Botje, M.A.J., QCDNUM16: A fast QCD evolution program, , Zeus Note 97-066www-h1.desy.de/h1/www/h1work/fit/h1fit.tools.htmlRoyon, C., Schoeffel, L., Bartels, J., Jung, H., Peschanski, R., (2001) Phys. Rev. D, 63, p. 074004Covolan, R.J.M., Montanha, J., Goulianos, K., (1996) Phys. Lett. B, 389, p. 176Goulianos, K., Montanha, J., (1999) Phys. Rev. D, 59, p. 114017Glück, M., Reya, E., Vogt, A., (1992) Z. Phys. C, 53, p. 651Covolan, R.J.M., Montanha, J., Pontes, A.N., Soares, M.S., in preparationBreitweg, J., (1998) Eur. Phys. J. C, 5, p. 41Adloff, C., (1999) Eur. Phys. J. C, 6, p. 421(2001) Eur. Phys. J. C, 20, p. 2
On the slope of the elastic differential cross sections
Making use of a model-independent analytical fit for the elastic hadron-hadron amplitude, recently developed, we investigate the slope of the proton-proton and antiproton-proton differential cross sections, as a function of the energy and the momentum transfer. We show that the predictions for these quantities are in agreement with the experimental data available and discuss the effect of the slope position as function of the momentum transfer.808
Diffractive Contribution to the Elasticity and the Nucleonic Flux in the Atmosphere
We calculate the average elasticity considering non-diffractive and single
diffractive interactions and perform an analysis of the cosmic-ray flux by
means of an analytical solution for the nucleonic diffusion equation. We show
that the diffractive contribution is important for the adequate description of
the nucleonic and hadronic fluxes in the atmosphere.Comment: 10 pages, latex, 2 figures (uuencoded PostScript
Regge Analysis of Diffractive and Leading Baryon Structure Functions from DIS
In this paper we present a combined analysis of the H1 data on leading baryon
and diffractive structure functions from DIS, which are handled as two
components of the same semi-inclusive process. The available structure function
data are analyzed in a series of fits in which three main exchanges are taking
into account: pomeron, reggeon and pion. For each of these contributions, Regge
factorization of the correspondent structure function is assumed. By this
procedure, we extract information about the interface between the diffractive,
pomeron-dominated, region and the leading proton spectrum, which is mostly
ruled by secondary exchanges. One of the main results is that the relative
reggeon contribution to the semi-inclusive structure function is much smaller
than the one obtained from a analysis of the diffractive structure function
alone.Comment: ps file, 22 pages, 5 figures. Totally revised version with major
changes, to appear in Physical Review
CONTRAINTERPRETAR O SOCIALISMO E RESSIGNIFICAR A MODERNIDADE: CONTRIBUIÇÕES DE LEONARDO PADURA
No texto a seguir, parto da observação do cenário brasileiro contemporâneo para evidenciar o enfastiado conhecimento político e social que tem a população, o qual proporciona mal-entendidos em relação à esquerda e ao socialismo. Mostra-se urgente, então, uma contrainterpretação do socialismo e, consequentemente, um novo entendimento da modernidade. Um dos caminhos para isso são as manifestações artísticas, incluindo a literatura. Por isso, num segundo momento do texto, analiso de que maneira o autor cubano Leonardo Padura, mais especificamente em El hombre que amaba a los perros, contribui com a contrainterpretação do socialismo e com a ressignificação da modernidade
Phenomenological analysis connecting proton-proton and antiproton-proton elastic scattering
Based on the behavior of the elastic scattering data, we introduce an almost
model-independent parametrization for the imaginary part of the scattering
amplitude, with the energy and momentum transfer dependences inferred on
empirical basis and selected by rigorous theorems and bounds from axiomatic
quantum field theory. The corresponding real part is analytically evaluated by
means of dispersion relations, allowing connections between particle-particle
and particle-antiparticle scattering. Simultaneous fits to proton-proton and
antiproton-proton experimental data in the forward direction and also including
data beyond the forward direction, lead to a predictive formalism in both
energy and momentum transfer. We compare our extrapolations with predictions
from some popular models and discuss the applicability of the results in the
normalization of elastic rates that can be extracted from present and future
accelerator experiments (Tevatron, RHIC and LHC).Comment: 17 pages, 17 figures, to appear in Eur. Phys. J.
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