General Colloquium:
General Colloquium:October 11 - 4:00pm Phys 223
(Coffee at 3:30p.m. in room 242)
Purdue University
Physics Department
collisions at 1.8 TeV"The fundamental structure of the vacuum contains many new degrees of freedom (quarks and gluons). The equation of state of the quark-gluon to hadron phase transition depends on the energy density and temperature of strongly interacting (hadronic) matter. The volume of the highly excited matter has been measured in Fermi Laboratory experiment E-735 using pion interferometry (Handbury Brown, Twiss). The energy is proportional to the number (pseudo rapidity density), of the charged particles emitted by the highly excited matter. Above the phase transition the hadronic matter (quark-gluon plasma) is deconfined. Decon-fined hadronic volumes 4.40 < V < 13.10 fm3, following a one dimensional (1D) expansion are found to be directly proportional to the charged particle pseudorapitity densities 6.75 < dNc /d
< 20.2. The hadronization temperature is T = 179.5 ± 5 (sys) MeV. Using the Bjorken 1D model, the hadronization energy density is _F = 1.10 ± 0.28 (stat) GeV/fm3 corresponding to an excitation of 24.8 ± 6.2 (stat) quark-gluon degrees of freedom.