ausblenden:
Schlagwörter:
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MPINP:
Präzisionsexperimente - Abteilung Blaum
Zusammenfassung:
Isochronous mass spectrometry has been applied in the storage ring CSRe to measure the masses of the Tz=−3/2 nuclei 27 P and 29 S. The new mass excess value ME( 29 S)=−3094(13)keV is 66(52) keV larger than the result of the previous 32 S( 3 He, 6 He) 29 S reaction measurement in 1973 and a factor of 3.8 more precise. The new result for 29 S together with those of the T=3/2 isobaric analog states in 29 P, 29 Si, and 29 Al fit well into the quadratic form of the isobaric multiplet mass equation (IMME). The mass excess of 27 P has been remeasured to be ME( 27 P)=−685(42)keV. By analyzing the linear and quadratic coefficients of the IMME in the Tz =−3/2 sd-shell nuclei, it was found that the ratio of the Coulomb radius parameters is R≈0.96 and is nearly the same for all T=3/2 isospin multiplets. Such a nearly constant R value, apparently valid for the entire light mass region with A>9, can be used to set stringent constraints on the isovector and isotensor components of the isospin nonconserving forces in theoretical calculations.
