417 research outputs found
New classes of summable Skyrmions
We introduce two new classes of summable Skyrmions. The Lagrangians they
originate from are explicitely constructed. We also analyse how some models
could be solve. Exact solutions are found for Skyrme-like toy models.Comment: 9 pages, revtex v3, EP-CPTh.A274.1193 and LAVAL-PHY-11-9
Skyrmion vibrational energies with a generalized mass term
We study various properties of a one parameter mass term for the Skyrme
model, originating from the works of Kopeliovich, Piette and Zakrzewski,
through the use of axially symmetric solutions obtained numerically by
simulated-annealing. These solutions allow us to observe asymptotic behaviors
of the B=2 binding energies that differ to those previously obtained. We also
decipher the characteristics of three distinct vibrational modes that appear as
eigenstates of the vibrational Hamiltonian. This analysis further examine the
assertion that the one parameter mass term offers a better account of baryonic
matter than the traditional mass term.Comment: 12 pages, 8 figure
The Stability of the Weak Skyrmions
We consider a set of gauge invariant terms in higher order effective
Lagrangians of the strongly interacting scalar of the electroweak theory. The
terms are introduced in the framework of the hidden gauge symmetry formalism.
The usual gauge term is known to stabilize the skyrmion but only in the large
vector mass limit. We find that adding higher-order gauge terms is insufficient
to insure stability. We then proceed to analyze other gauge invariant
interaction terms. Some of the conclusions also apply to QCD skyrmions.Comment: 3 pages, revtex v3, (optional), LAVAL-PHY-11-9
Spitzer Observations of Galaxy Clusters
We present preliminary results of a project to study three rich nearby clusters of galaxies with the Spitzer space telescope. The Spitzer observations in the four IRAC and three MIPS bands cover a region up to three virial radii, approximately, and have been recently completed. On the basis of the first Spitzer images, we followed up spectroscopically the far-infrared sources with the multi-fiber spectrograph HYDRA on the WIYN telescope. 70% of the sources brighter than 0.3 mJy at 24 μm and r’ < 20.5 have been observed for a total of 1078 spectra. For 87% of them we were able to measure redshifts obtaining 50 to 100 members for the different clusters. This first study shows that the far-IR sources in these clusters are predominantly powered by star formation and clustered in regions far from the center. In the case of A1763, they seem to be situated along a filament supporting the idea of infalling galaxies experiencing bursts of star formation during their first contact with the hot intra-cluster medium
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