<p>The relation between four-dimensional <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>S</mi><mi>O</mi><mo stretchy="false">(</mo><mn>4</mn><mo stretchy="false">)</mo></math> pure Yang-Mills theory and gravity is discussed. The functional integral for Yang-Mills theory is rewritten in terms of the gravity metric and Riemann tensors. This relation is shown to also provide a simple way to derive the linear potential resulting from the average Wilson loop in pure Yang-Mills theory.</p>

Russia

A.G. Shuvaev

New aspects of the gauge-gravity relation

A new approach to deal with the scattering amplitudes in Glauber theory is proposed. It relies on the use of a generating function, which has been explicitly found. The method is applied to the analytical calculation of the nucleus-nucleus elastic scattering amplitudes in the all interaction orders of the Glauber theory.

Yu. M. Shabelski

Generating function for nucleus-nucleus scattering amplitudes in Glauber theory

The large mass of the η′ meson indicates that a sizeable gluon component is present in the meson wave function. However, the χc0 and χc2 decays to η′ mesons, which proceed via a purely gluonic intermediate state and we would therefore naïvely expect to be enhanced by such a component, are in fact relatively suppressed. We argue that this apparent contradiction may be resolved by a proper treatment of interference effects in the decay. In particular, by accounting for the destructive interference between the quark and gluon components of the η′ distribution function, in combination with a model for strange quark mass effects, we demonstrate that the observed χc(0,2)→η(′)η(′) branching ratios can be reproduced for a reasonable gluon component of the η′ , η mesons.

United Kingdom

L.A. Harland-Lang

V.A. Khoze

M.G. Ryskin

Ï c Decays and the Gluon Component of the î· â² , î· Mesons

High energy (CERN SPS and LHC) inelastic pp ( pp¯ ) scattering is treated in the framework of the additive quark model together with Pomeron exchange theory. We extract the midrapidity inclusive density of the charged secondaries produced in a single quark–quark collision and investigate its energy dependence. Predictions for the πp collisions are presented.

Midrapidity inclusive densities in high energy pp collisions in additive quark model

We study the prompt production of the χc(1+) and χb(1+) mesons at high energies. Unlike χ(0+,2+) production, χ(1+) mesons cannot be created at LO via the fusion of two on-mass-shell gluons, that is, gg→χc,b(1+) are not allowed. However, the available experimental data show that the cross sections for χc(1+) and χc(2+) are comparable. We therefore investigate four other χ(1+) production mechanisms: namely, (i) the standard NLO process gg→χc,b(1+)+g , (ii) via gluon virtuality, (iii) via gluon reggeisation and, finally, (iv) the possibility to form χc,b(1+) by the fusion of three gluons, where one extra gluon comes from another parton cascade, as in the Double Parton Scattering processes.

A.D. Martin

Inclusive prompt χc,b(1++) production at the LHC

High energy (CERN SPS and LHC) pp ( pp¯ ) scattering is treated in the framework of the Additive Quark Model together with Pomeron exchange theory. Reasonable agreement with experimental data is achieved both for the elastic scattering and for the diffractive dissociation with natural parameters for the strong matter distribution inside proton.