Experimental data for $M1\mathrm{}$ matrix elements in the $T=1/2\mathrm{}$ mirror nuclei ${}^{27}\mathrm{Al}$ and ${}^{27}\mathrm{Si}$ are used to determine the isoscalar and isovector $M1\mathrm{}$ components. The obtained isovector $M1\mathrm{}$ matrix elements are compared to the Gamow-Teller matrix elements deduced from $\beta$ decay and the ${}^{27}\mathrm{Al}{(}^3\mathrm{He}{,t)}^{27}\mathrm{Si}$ charge exchange reaction to determine the contributions of the isovector spin and orbital components. The exchange current effects are taken into account. The results are compared with shell model calculations.

• Received 22 February 2000

DOI:https://doi.org/10.1103/PhysRevC.62.044314