Possibility of shears mechanism due to attractive interaction in the island of A 140 region

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The present work identify an island in the values of dimensionless parameter χ as +0.10 < χ < +0.55 outside which no magnetic rotational (MR) bands due to the repulsive interaction would be observed. The semi-classical calculations within the hybrid shears mechanism with the principal axis cranking model (HSPAC) reveal the possibility of the shears band due to the attractive interaction for nuclei in A 140 region. Though the limited information exists in literature, the HSPAC calculation exhibits the dipole bands above the 4389-keV and 4160-keV excited states in ¹⁴⁵Sm and ¹⁴⁶Eu nuclei, respectively, demand their candidature of the attractive shears bands. Other interesting consequence of the HSPAC calculations is the increasing nature of the B(M1) and B(E2) transition strengths with spin unlike the decreasing nature of the transition strengths (B(M1) and B(E2) values) of the MR bands. Thus measurement of the transition probability has been required on urgent basis to validate the strong candidature of such an extreme excitation mechanism in ¹⁴⁵Sm and ¹⁴⁶Eu nuclei.