2,919 research outputs found
On the Quantization of the Abelian Chern-Simons Coefficient at Finite Temperature
We show that when the Abelian \CS\ theory coupled to matter fields is
quantized in a vacuum with non vanishing magnetic flux (or electric charge),
the requirement of gauge invariance at finite temperature leads to the
quantization of the \CS\ coefficient and its quantum corrections, in a manner
similar to the non-Abelian case.Comment: 11 pages, LaTeX, no figures, no special macros. Some discussion and
references added. A minor error corrected. Final version to appear in Phys.
Lett.
Attractive Forces Between Electrons in QED
Vacuum polarization effects are non-perturbatively incorporated into the
photon propagator to eliminate the severe infrared problems characteristic of
QED. The theory is thus rephrased in terms of a massive vector boson whose
mass is . Subsequently, it is shown that electron-electron bound
states are possible in QED.Comment: revtex, 10 pages and four figures, IFUSP/P-98
Antimatter production in proton-proton and heavy-ion collisions at ultrarelativistic energies
One of the striking features of particle production at high beam energies is
the near equal abundance of matter and antimatter in the central rapidity
region. In this paper we study how this symmetry is reached as the beam energy
is increased. In particular, we quantify explicitly the energy dependence of
the approach to matter/antimatter symmetry in proton-proton and in heavy-ion
collisions. Expectations are presented also for the production of more complex
forms of antimatter like antihypernuclei.Comment: 7 pages, 5 figure
Production of nuclei and antinuclei in pp and Pb-Pb collisions with ALICE at the LHC
We present first results on the production of nuclei and antinuclei such as
(anti)deuterons, (anti)tritons, (anti)3He and (anti)4He in pp collisions at
\s = 7 TeV and Pb-Pb collisions at \sNN = 2.76 TeV. These particles are
identified using their energy loss (dE/dx) information in the Time Projection
Chamber of the ALICE experiment. The Inner Tracking System gives a precise
determination of the event vertex, by which primary and secondary particles are
separated. The high statistics of over 360 million events for pp and 16 million
events for Pb-Pb collisions give a significant number of light nuclei and
antinuclei (Pb-Pb collisions: \sim30,000 anti-deuterons() and \sim4
anti-alpha()). The predictions of various particle ratios from the
THERMUS model is also discussed.Comment: 4 pages, 5 figures, parallel talk at Quark Matter 2011, May 23rd-28th
2011, Annecy, Franc
Role of Protected Block Curriculum in Surgical Education
A protected block curriculum for surgical resident training began at the Medical College of Wisconsin in 2005. The curriculum has evolved with time as educational emphasis has changed. However, the concept of having resident learners relieved of clinical duty to focus on learning has not changed. Separate protected block curriculums are held for PGY1 and PGY 2 during which residents have no clinical responsibilities. These periods are defined at the beginning of each academic year and are distributed to all faculties. The systematic design, implementation, and evaluation of the protected block curriculum (PBC) Model provides an educationally grounded model for training surgical residents consistent with accreditation council for graduate medical education (ACGME) competency mandates. Resident evaluations consistently support the use of our PBC as a method to attain and practice skill sets in a nonthreatening environment. Faculty benefits are able to evaluate residents’ knowledge, skills, and attitudes in a nonclinical setting and engage residents as individuals. The format extended into the PGY3–5 years of training as it evolved. Over more than a decade of using PBC, we have performed a number of analyses on the program and even determined a cost for the program. The program continues to be adjusted to new technology and curriculum initiatives
On The Finite Temperature Chern-Simons Coefficient
We compute the exact finite temperature effective action in a 0+1-dimensional
field theory containing a topological Chern-Simons term, which has many
features in common with 2+1-dimensional Chern-Simons theories. This exact
result explains the origin and meaning of puzzling temperature dependent
coefficients found in various naive perturbative computations in the higher
dimensional models.Comment: 11 pages LaTeX; no figure
Induced Parity-Breaking Term at Finite Chemical Potential and Temparature
We exactly calculated the parity-odd term of the effective action induced by
the fermions in 2+1 dimensions at finite chemical potential and finite
temperature. It shows that gauge invariance is still respected. A more gerneral
class of background configurations is considered. The knowledge of the reduced
1+1 determinant is required in order to draw exact conclusions about the gauge
invariance of the parity-odd term in this latter case.Comment: 8 pages, LATEX, no figure
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