Squark mass measurement in the long-lived stau scenario at the LHC

The long-lived stau scenario is an interesting possibility at the LHC. We study squark mass measurements in this scenario; in particular, we show that left- and right-handed squark masses are both measurable. In SUSY events, multiple jets are expected, which become a source of combinatorial backgrounds. In order to reduce such backgrounds a hemisphere analysis is applied, and we discuss mass measurements of squarks in decay modes of q˜L into qW˜0 or q′W˜± and also q˜R into qB˜.