Gosia
From GOSIA
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===Analysis of Coulomb excitation data=== | ===Analysis of Coulomb excitation data=== | ||
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| + | The motivation for development of Gosia was to | ||
| + | implement the capability to extract measured | ||
| + | <math>E\lambda</math> | ||
| + | matrix elements model-independently from Coulomb excitation data. The first | ||
| + | major task required to achieve this goal was to design experiments covering a | ||
| + | wide dynamic range of Coulomb excitation strength that provide sufficient | ||
| + | experimental data to overdetermine the many unknown matrix elements. | ||
| + | Experimental techniques were developed to achieve this requirement in the | ||
| + | 1980's and primarily involved Coulomb excitation measurements over a wide | ||
| + | range of both scattering angle and unexcited nucleus | ||
| + | <math>Z</math> value. The second major task was the development of Gosia to | ||
| + | model-independently extract the matrix elements via a least-squares search of | ||
| + | the data. During the 1980's and early 1990's the ready availability of beam | ||
| + | time at heavy-ion accelerator facilities, the availability of high-efficiency | ||
| + | <math>p-\gamma</math> detector facilities, and access to fast computer systems needed for the Gosia | ||
| + | least-squares searches, enabled the first model-independent extraction of | ||
| + | <math>E\lambda</math> | ||
| + | matrix elements from multiple Coulomb excitation data. These fairly complete | ||
| + | sets of E2 matrix elements made it possible to exploit the rotational invariants | ||
| + | technique to extract the underlying quadrupole collective degrees of freedom | ||
| + | directly from the Coulomb excitation data. Note that it is not viable to | ||
| + | perform a completely model-independent analysis in that models extrapolate | ||
| + | from the set of measured | ||
| + | <math>E\lambda</math> | ||
| + | matrix elements to estimate other matrix elements that are insensitive to the | ||
| + | data set but play a weak role in the Coulomb excitation process, for example | ||
| + | the influence of virtual excitation of the highest spin states or of | ||
| + | excited-state static electric quadrupole moments. | ||
[[Model_independent_analysis | Model-independent analysis]] | [[Model_independent_analysis | Model-independent analysis]] | ||
