11,834 research outputs found
Azimuthal anisotropy () of high-p and direct in Au+Au collisions at = 200 GeV
Preliminary results from the STAR collaboration of the azimuthal anisotropy
of and direct photon () at high transverse
momentum (p) from Au+Au collisions at center-of-mass energy
~GeV are presented. A shower-shape analysis is used to
select a sample free of direct photons () and a sample rich in direct
photons . The relative contribution of background in the
sample is determined assuming no associated charged particles
nearby . The of direct photons ()
at mid-rapidity () and high p (~GeV/) is extracted from those of and
neutral particles measured in the same kinematic range. In mid-central Au+Au
collisions (10-40), the of () and
charged particles () are found to be 0.12 and nearly
independent of p. The measured is positive
finite and systematically smaller than that of and charged particles
by a factor of 3. Although the large at such high
p might be partially due to the path-length dependence of energy loss,
the non-zero value of indicates a bias of the reaction
plane determination due to the presence of jets in the events. Systematic
studies are currently in progress.Comment: 4 pages, 2 figures, Hot Quarks 2010, LaLonde Franc
Mooses, Topology and Higgs
New theories of electroweak symmetry breaking have recently been constructed
that stabilize the weak scale and do not rely upon supersymmetry. In these
theories the Higgs boson is a weakly coupled pseudo-Goldstone boson. In this
note we study the class of theories that can be described by theory spaces and
show that the fundamental group of theory space describes all the relevant
classical physics in the low energy theory. The relationship between the low
energy physics and the topological properties of theory space allow a
systematic method for constructing theory spaces that give any desired low
energy particle content and potential. This provides us with tools for
analyzing and constructing new theories of electroweak symmetry breaking.Comment: 16 pages, 11 figure
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