Direct probes of linearly polarized gluons inside unpolarized hadrons

We show that linearly polarized gluons inside unpolarized hadrons can be directly probed in jet or heavy quark pair production in electron-hadron collisions. We discuss the simplest cos2? asymmetries and estimate their maximal value, concluding that measurements of the unknown linearly polarized gluon distribution in the proton should be feasible in future Electron-Ion Collider or Large Hadron electron Collider experiments. Analogous asymmetries in hadron-hadron collisions suffer from factorization breaking contributions and would allow us to quantify the importance of initial- and final-state interactions.     

Cationic crosslinking of solid dgeba resins with ytterbium(III) trifluoromethanesulfonate as initiator

Solid bisphenol-A epoxy resin of medium molecular mass was cured using a Lewis acid initiator (ytterbium(III) trifluoromethanesulfonate) in three different proportions (0.5, 1 and 2 phr). A kinetic study was performed in a differential scanning calorimeter. The complete kinetic triplet was determined (activation energy, pre-exponential factor, and integral function of the degree of conversion) for each system. A kinetic analysis was performed with an integral isoconversional procedure (free model), and the kinetic model was determined both with the Coats-Redfern method (the obtained isoconversional value being accepted as the effective activation energy) and through the compensation effect. All the systems followed the same isothermal curing model simulated from non-isothermal ones. The growth-of-nuclei Avrami kinetic model A_3/2 has been proposed as the polymerization kinetic model. The addition of initiator accelerated the reaction especially when 2 phr was added. 0.5 and 1 phr showed very few kinetic differences between them.     

Hunting for glueballs in electron-positron annihilation

We calculate the cross section for the exclusive production of J(PC)=0(++) glueballs G0 in association with the J/psi in e(+)e(-) annihilation using the perturbative QCD factorization formalism. The required long-distance matrix element for the glueball is bounded by CUSB data from a search for resonances in radiative Upsilon decay. The cross section for e(+)e(-)-->J/psi+G0 at sqrt[s]=10.6 GeV is similar to exclusive charmonium-pair production e(+)e(-)-->J/psi+h for h=eta(c) and chi(c0), and is larger by a factor of 2 than that for h=eta(c)(2S). As the subprocesses gamma(*)-->(cc)(cc) and gamma(*)-->(cc)(gg) are of the same nominal order in perturbative QCD, it is possible that some portion of the anomalously large signal observed by Belle in e(+)e(-)-->J/psiX may actually be due to the production of charmonium-glueball J/psiG(J) pairs.