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Boris Kopeliovich

Publications and source records attributed to Boris Kopeliovich.

20 records · Page 2Linked to original sources

In Search for (QUANTUM) Color Transparency

Color transparency (CT) is an effect of suppression of nuclear shadowing of hard reactions, closely related to the color screening. A brief review of theoretical development and experimental search for CT, failed and successful, are presented. A special emphasis is made on a quantum-mechanical nature of CT, as opposed to a wide spread erroneousclassical treatment of this phenomenon. The typical predictions of the classical approach, all contradicting quantum mechanics are: - factorization of cross section of hard reactions on a nucleus;\\ - "nuclear transparency", a normalized ratio of nuclear to nucleon cross sections, cannot exceed one;\\ - the larger is a radius of a hadron, the stronger it attenuates in a nucleus;\\ - the higher is the energy of hadrons participating in a hard reaction, the less is the nuclear attenuation;\\ - due to CT hard processes provide a better opportunity to study Fermi-momentum distribution, than soft reactions; etc. (Talk presented at XXVIII Rencontres de Moriond, March 1993)

hep-ph↗

Hadronization in Nuclear Matter

Nuclei are unique analyzers of the space-time development of jets at early stage. We argue that the gluon bremsstrahlung, rather than the color string, is the main mechanism of hadronization of highly virtual quarks produced in a hard interaction. It results in an energy- and time-independent density of energy loss, like a color string, but steeply dependent on the quark virtuality. Effects of formation zone (FZ) and color transparency (CT) substantially affect the jet quenching in a nuclear matter. The latter also plays an important role in the broadening of transverse momentum distribution of a quark passing a nucleus. Parameter-free calculations provide a good description of available data on nuclear effects in the leading hadron production in deep-inelastic lepton scattering, back-to-back high-$p_T$ hadron pair production, broadening of the transverse momentum distribution in the Drell-Yan process of lepton pair production on nuclei.

hep-ph↗