Informal Pizza Seminar
Pondering the φ puzzle
Kevin Haglin
Department of Physics and Astronomy
Saint Cloud State
University
Based on its vacuum properties, the φ meson is expected to decay outside
the fireball generated in heavy-ion collisions, yet there is evidence from
experiment to the contrary. One-loop thermal effects turn out to be rather
small, leaving the spectral function and also the lifetime unchanged.
Two-loop effects contribute, among other ways, to collisional broadening and,
in contrast, are rather significant. We use an in-medium spectral function
for the φ to extract a lifetime at finite temperature. The model
predicts a lifetime which is shortened sufficiently to allow decay inside the
fireball. Dilepton decay channels could be used to probe these collective
many-body effects.
Wednesday, July 14th 200, 13:00
Ernest Rutherford Physics Building, room 326
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