Locate the mass at which the sideband constraint becomes ineffective

Determine the higgsino mass at which the high-energy sideband test ceases to impose a significant constraint on non-thermally produced higgsinos explaining the LZ event.

Background

The appendix examines higgsinos with masses below and above the standard thermal value. A 500 GeV higgsino predicts substantially fewer events in the high-energy sideband, while higgsinos above approximately 800 GeV are more strongly affected by the sideband test.

Although the paper identifies the qualitative transition region, it does not determine the precise mass at which the sideband constraint changes from weak to significant.