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