Departamento de Fisica, Universidad de Santiago de Chile,

Casilla 307, Santiago 2, CHILE

E-mail: ematute@lauca.usach.cl

**Topological charges, prequarks and presymmetry: a topological
approach to quark fractional charges**

**Abstract:**

A topological approach to quark fractional charges, based on charge
constraints unexplained by the Standard Model of particle physics, is discussed.
Charge fractionalization is related to a tunneling process occurring in
time between pure gauge field configurations at the far past and future
associated with integer-charged bare quarks, named prequarks. This transition
conforms to a topologically nontrivial configuration of the weak gauge
fields in Euclidean spacetime. In this context, an electroweak *Z*_{2}
symmetry between bare quarks and leptons, named presymmetry, is revealed.
It is shown that an effective topological charge equal to the ratio between
baryon number and the number of fermion generations may be associated with
baryonic matter. The observed conservation of baryon number is then connected
with the conservation of this bookkeeping charge on quarks. Similar results
are obtained for leptons in the dual scenario with local quark charges.