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Posgrado en Física
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Dr. Adnan Bashir
Ph. D. on Physics,
University of Durham,
Durham, England (1995).
adnan at ifm.umich.mx
Understanding the origin of mass, in particular that of the fermions, is
one of the most uncanny problems which lie at the very frontiers of particle
physics. Although the celebrated Standard Model accommodates these masses in
a gauge invariant fashion, it fails to predict their values. Moreover, the
mass thus generated accounts for only a very small percentage of
the mass which permeates the visible universe. Most of the observed mass is
accounted for by the strong interactions which bind quarks into protons and
neutrons. How does that exactly happen in its quantitative details is still
an unsolved mystery. Lattice formulation of quantum chromodynamics (QCD) or
continuum studies of its Schwinger-Dyson equations (SDEs) are two of
the non-perturbative means to try to unravel how quarks, starting from
negligible current masses can acquire enormously large constituent masses to
account for the observed proton and neutron masses. Analytical studies of
SDEs in this context are extremely hard as one has to resort to truncation
schemes whose quantitative reliability can be established only after a very
careful analysis. Let alone the far more complicated realm of QCD, arriving
at reliable truncation schemes in simpler scenarios such as quantum
electrodynamics (QED) has also proved to be a hard nut to crack. Along with
my colleagues and students, we have been making efforts to understand how
the dynamical generation of mass can be understood in a reliable way through
SDEs of gauge theories in various contexts such as in arbitrary space-time
dimensions $d$ as well as $d \leq 4$, at finite temperatures and in the
presence of magnetic fields.
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Versión en castellano 