TeV‐ and MeV‐Physics Out of an Model

The standard electroweak interaction is here re‐assessed to accommodate two different situations in Particle Physics. The first one is a ‐model at the TeV‐scale physics. The second one tackles the recent discussion of a possible fifth force mediated by a 17‐MeV X‐boson associated with an electron‐positron emission in the transition of an excited 8‐Beryllium to its ground state. The anomaly‐free model that provides these two scenarios is based on an ‐symmetry. It yields a new massive neutral boson, an exotic massive neutral fermion, right‐neutrinos and an additional neutral Higgs particle, which stems from a supplementary Higgs field, introduced along with the usual Higgs doublet responsible for the electroweak breaking and the masses of and Z⁰. Yukawa interactions of the two scalars generate the masses of the Standard Model leptons, neutrinos and a new exotic fermion of the model. The vacuum expectation values of the Higgses fix up two independent energy scales. One of them is the well‐confirmed electroweak scale, 246 GeV, whereas the other one is set up by adopting an experimental estimate for the ‐mass.     

Porous crosslinked spherical resins for diversified applications: packing materials for size exclusion chromatography

Improvements in the synthesis of porous polymers for different applications have been carried out in our laboratory. Beads of poly(styrene-co-divinylbenzene) with morphology adequate to the application at hand were prepared. Packing materials for size exclusion chromatography (SEC) weve prepared by single-step swelling and polymerization (SSWP) and by modified suspension polymerization (MSP). High values of exclusion limit (10⁶ and 8.0x10⁶) were attained for SEC columns packed with poly(styrene-co-divinylbenzene) synthesized using high proportions of polystyrene, as porogen agent and divinylbenzene. The maximum values of exclusion limits were attained for SEC columns packed with beads prepared by SSWP method.