Two-neutrino double electron capture of $^{124}$Xe in the first
LUX-ZEPLIN exposure
Two-neutrino double electron capture of $^{124}$Xe in the first
LUX-ZEPLIN exposure
The broad physics reach of the LUX-ZEPLIN (LZ) experiment covers rare phenomena beyond the direct detection of dark matter. We report precise measurements of the extremely rare decay of $^{124}$Xe through the process of two-neutrino double electron capture (2$\nu$2EC), utilizing a $1.39\,\mathrm{kg} \times \mathrm{yr}$ isotopic exposure from the first LZ …