We determine the maximal cocliques of size ≥ 4q2 + 5q + 5 in the Kneser graph on point-plane flags in PG(4, q). The maximal size of a coclique in this graph is (q2 + q + 1)(q3 + q2 + q + 1).

We study a new mechanism for hadronic helicity flip in high energy hard exclusive reactions. The mechanism proceeds in the limit of perfect chiral symmetry, namely without any need to flip a quark helicity. The fundamental feature of the new mechanism is the breaking of rotational symmetry of the hard collision by a scattering plane in processes involving independent quark scattering. We show t...

We review the present data on high-energy, spin-dependent photoabsorption. We find a strong isotriplet term in (σA − σP ) which persists from Q2 ∼ 0.25GeV2 to high Q2 polarised deep inelastic scattering. For Q2 ∼ 4GeV2 and x between 0.01 and 0.12 the isotriplet part of g1 behaves as g (p−n) 1 ∼ x 1 2 , in contrast to soft Regge theory which predicts that g (p−n) 1 should converge as x → 0. The ...

We have studied several features of the production of charged hadron pairs by qy collisions. We have measured the j” partial width I”,,,(Q2) for & in the range 0 < Q2 < 1.4 Gep/c2, and obtained $.,rr = 2.52 f 0.13 f 0.38 keV at q2 = 0. The measured Q2 dependence is in agreement with the generalized vector dominance model. The cross section for 77 ---) (?r+n+ K+K-) in the mass region 1.6 GeV/c2 ...

We analyse in this article the critical behavior of M q1-state Potts models coupled to N q2-state Potts models (q1, q2 ∈ [2..4]) with and without disorder. The technics we use are based on perturbed conformal theories. Calculations have been performed at two loops. We already find some interesting situations in the pure case for some peculiar values of M and N with new tricritical points. When ...

We give a reformulation of a six-parameter family of coupled Painlevé VI systems with affine Weyl group symmetry of type D (1) 6 . We also study some Hamiltonian structures of this system. 0. Introduction In the present paper, we propose a 6-parameter family of four-dimensional coupled Painlevé VI systems with affine Weyl group symmetry of type D (1) 6 . Our differential system is equivalent to...

ing from the embeddability relation between order types, define a quasi-order to be a reflexive, transitive relation. Throughout this paper, the letters Q and R will range over quasi-ordered sets and classes. Various quasi-ordered spaces will be defined; in each case we will use the symbol < (perhaps with subscripts) to denote the quasi-order under consideration. If q1, q2 E Q, write ql < q2 to...

We critically review the QCD predictions for the cross sections σL and σT for diffractive ρmeson electroproduction in longitudinally and transversely polarised states in the HERA energy region. We show that both perturbative and non-perturbative approaches which involve convolution with the ρ meson wave function predict values of σT which fall-off too quickly with increasing Q2, in comparison w...

(7) 2 · (p+q) ∈ L(p,q). (8) If p1 = q1 and q1 = (p1)1 and p2 ≤ q2 and q2 ≤ (p1)2, then q ∈ L(p, p1). (9) If p1 ≤ q1 and q1 ≤ (p1)1 and p2 = q2 and q2 = (p1)2, then q ∈ L(p, p1). (10) Let D be a non empty set, given i, j, and M be a matrix over D. If 1 ≤ i and i ≤ lenM and 1 ≤ j and j ≤ widthM, then 〈i, j〉 ∈ the indices of M. (11) If 1 ≤ i and i + 1 ≤ lenG and 1 ≤ j and j + 1 ≤ widthG, then 2 · ...

For gauge theories which admit a dual string description, we analyze deep inelastic scattering at strong ’t Hooft coupling and high energy, in the vicinity of the unitarity limit. We discuss the onset of unitarity corrections and determine the saturation line which separates weak scattering from strong scattering in the parameter space of rapidity and photon virtuality. We discover that the app...