Background-Free Intensity Autocorrelation for Femtosecond X-Ray PulsesRemoveTaito Osaka, Shotaro Matsumura, Masafumi Miyake, Yasuhisa Sano, Ichiro Inoue, Yuichi Inubushi, Kensuke Tono, Kenji Tamasaku, and Makina YabashiPhys. Rev. Lett. 136, 195002 (2026)
