Soft Photoproduction Physics

Several topics of interest in soft photoproduction physics are discussed. These include jet universality issues (particle flavour composition), the subdivision into event classes, the buildup of the total photoproduction cross section and the effects of multiple interactions.Comment: 10 pages, LaTeX2e, no figures, to appear in the proceedings of the Durham Workshop on HERA Physics, ``Proton, Photon and Pomeron Structure'', 17--23 September 1995, Durham, U.

The Q2Q^2 dependence of the hard diffractive photoproduction of vector meson or photon and the range of pQCD validity

We consider two coupled problems. We study the dependence on photon virtuality $Q^2$ for the semihard quasi--elastic photoproduction of neutral vector mesons on a quark, gluon or real photon (at $s\gg p_{\bot}^2,\;Q^2; \; p_{\bot}^2\gg \mu^2 \approx (0.3$ GeV)$^2$). To this end we calculate the corresponding amplitudes (in an analytical form) in the lowest nontrivial approximation of perturbative QCD. It is shown that the amplitude for the production of light meson varies very rapidly with the photon virtuality near $Q^2=0$. We estimate the bound of the pQCD validity region for such processes. For the real incident photon the obtained bound for the $\rho$ meson production is very high. This bound decreases fast with the increase of $Q^2$, and we expect that the virtual photoproduction at HERA gives opportunity to test the pQCD results. The signature of this region is discussed. For the hard Compton effect the pQCD should work good at not too high $p_{\bot}$, and this effect seems measurable at HERA.Comment: ReVTeX, 36 pages, 5 Postscript figures, uses epsf.st

The Gottfried sum from the ratio F2n/F2p

Amaudruz P, Arneodo M, Arvidson A, et al. The Gottfried sum from the ratio F2n/F2p. Phys.Rev.Lett. 1991;66(21):2712-2715

За кадры. 1995. № 8

Одна строка в трудовой книжке[В канун Дня геолога...] / Б. И. СпиридоновНа ученом совете институтаНа вопросы сотрудников отвечает ректор / Ю. П. Похолков1941-1945. Томская наука - фронту1941-1945. Политехники на учебном фронте1941-1945. Политехники на трудовом фронтеБизнес-центр ТПУ: 2 года работ