Reggeons in diffractive interactions in deep inelastic scattering at HERA

The "triple-Regge" analysis of subleading Reggeon contributions to the diffractive structure function in DIS at HERA is presented. The recently published data allow to estimate the only free parameter of the analysis related to the ratio of the RRP and PPP couplings. The large value of this ratio is prefered which is in agreement with analyses of soft hadronic interactions. The role of the subleading Reggeons as well as pions for the fast forward neutron production in diffractive processes is estimated. The forward piN state production is also discussed.Comment: 6 pages, 2 figures, uses sprocl.sty and epsfig. To be published in Proceedings of the Madrid low-x Workshop, Miraflores de la Sierra, June 18-21,199

Geometric scaling for the total gamma^* p cross section in the low x region

We observe that the saturation model of deep inelastic scattering, which successfully describes inclusive and diffractive data at small x, predicts a geometric scaling of the total gamma^* p cross section in the region of small Bjorken variable x. The geometric scaling in this case means that the cross section is a function of only one dimensionless variable tau = Q^2 R_0^2(x), where the function R_0(x) (called saturation radius) decreases with decreasing x. We show that the experimental data from HERA in the region x<0.01 confirm the expectations of this scaling over a very broad region of Q^2. We suggest that the geometric scaling is more general than the saturation model.Comment: 12 pages, 4 figures, LaTeX, revised version to appear in journal. 1 new figure, several new references added, extended discussion on saturation radiu

Redescription des genres Septatrypa KOZLOWSKI, 1929 et Dubaria TERMIER, 1936 (Brachiopoda, Atrypida, Lissatrypidae)

The serial sections carried out on specimens of Septatrypa secreta KOZLOWSKI, 1929 and Dubaria lantenoisi TERMIER, 1936 show that the former of these species has a structure of the type "septalium" in the brachial valve. This "septalium" arises from the presence of an apical thickening which joins the median septum and the posterior and external part of the socket plates. This observation confirms the opinion of the authors who consider these two genera - of which the above species are the type species - to be distinct. The lectotype of Dubaria lantenoisi is designated. Some controversial genera of Septatrypinae are briefly discussed

Quark model with chiral-symmetry breaking and confinement in the Covariant Spectator Theory

We propose a model for the quark-antiquark interaction in Minkowski space using the Covariant Spectator Theory. We show that with an equal-weighted scalar-pseudoscalar structure for the confining part of our interaction kernel the axial-vector Ward-Takahashi identity is preserved and our model complies with the Adler-zero constraint for pi-pi-scattering imposed by chiral symmetry.Comment: 4 pages, 2 figures; 21st International Conference on Few-Body Problems in Physics, May 18 - 22, 2015, Chicago, US