  High-spin states of 84Sr were populated through the reaction 70Zn(18O,
4n)84Sr at 75 MeV beam energy. Measurement of excitation function, gamma-gamma
coincidences, directional correlation of oriented states (DCO) ratios and
gamma-transition intensities were performed using eight anticompton HPGe
detectors and one planar HPGe detector. Based on the measured results, a new
level scheme of 84Sr was established in which 12 new states and nearly 30 new
gamma-transitions were identified in the present work. The positive-parity
states of the new level scheme were compared with results from calculations in
the framework of the projected shell model (PSM). One negative-parity band was
extended to spin I=19 and it can be found that in the high-spin states the
gamma-transition energies show the nature of signature staggering. The
negative-parity band levels are in good agreement with the deformed
configuration-mixing shell model (DCM) calculations.
