10,168 research outputs found
Baryon octupole moments
We report on a calculation of higher electromagnetic multipole moments of
baryons in a non-covariant quark model approach. The employed method is based
on the underlying spin-flavor symmetry of the strong interaction and its
breaking.We present results on magnetic octupole moments of decuplet baryons
and discuss their implications.Comment: 3 page
Exchange Currents in Photoproduction of Baryon Resonances
We calculate photoexcitation amplitudes for several nucleon and delta
resonances. We use a chiral quark model including two-body exchange currents.
The two-body currents give important contributions. For the delta (1232) and
the D13 (1520) we observe that the individual exchange current contributions
considerably cancel each other while in the case of the Roper resonance and the
S11 (1535) we get a reinforcement of the two-body amplitudes. In comparison
with present experimental data, we obtain both for the S11 (1535) and for the
Roper resonance an improvement with respect to the impulse approximation.Comment: 9 pages, 1 figur
Search for supersymmetry in events with a Z boson, jets and missing energy
We present a search for Physics beyond the Standard Model (SM) in final
states with a Z boson, jets and missing transverse energy, using a data sample
collected in 2011 by the CMS detector at the Large Hadron Collider
corresponding to an integrated luminosity of 2.1 /fb. This final state is
predicted in several models of Physics beyond the SM, including supersymmetry.
A novel analysis method is exploited, the Jet-Z Balance method, and a precise
determination of the total SM background is obtained using a control sample
from data. In the absence of any significant excess beyond the SM background,
upper limits are set on simple models of supersymmetry, and further information
is provided to allow confrontation of other models to these results.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011),
Paris, France, November 14-18 2011, 3 pages, 7 figure
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