Parts | Days | Selection | Search | Downloads | Help

HK: Hadronen und Kerne

HK 60: Instrumentation VI, Detector Systems

HK 60.3: Talk

Thursday, March 19, 1998, 14:45–15:00, A

Dilepton decay of Giant Monopole Resonances: a feasibility study — •K. van der Schaaf¹, J.C.S. Bacelar¹, Y. Blumenfeld², D. Chmielewska³, N. Frascaria², M.N. Harakeh¹, A. Krasznahorkay⁴, P. Paul⁵, J.A. Scarpaci², S. Schadmand⁶, Z. Sujkowski³, T. Suommijärvi², and A. van der Woude¹ — ¹KVI, Groningen — ²IPN, Orsay — ³Swierk, Poland — ⁴Debrecen, Hungary — ⁵SUNY, USA — ⁶Univ. Giessen, Giessen

Giant Monopole Resonances (ISGMR and IVGMR) represent the breathing-mode oscillations of the nucleus. Their strength is constrained by sum rules, and their energy is related to the nuclear compressibility. The ISGMR has been well established in heavy nuclei with inelastic α scattering at 0^∘, but for light and medium mass nuclei one does not find the total sum-rule strength. The search for the IVGMR is done using charge-exchange reactions.

We propose to use the dilepton decay channel to identify the monopole character of these resonances. This electromagnetic decay channel is particularly sensitive to monopole decays. Due to the small partial decay width of this channel a highly efficient and segmented detector is required. The Plastic Ball, which recently arrived at the KVI, has the required specifications. Simulations show that the sensitivity to the dilepton monopole yield allow the study of the ISGMR even in light and medium mass nuclei. Simulations are also shown for the study of the IVGMR.