/download/public/2026/lectures/semester_1/Particle%20Physics/Experimental_Part/Exercise_Sheets/ES1_relativity.pdf.html to https://box.in2p3.fr/s/qNKwGaMQHRE68M5/download?path=%2F2026%2Flectures%2Fsemester_1%2FParticle Physics%2FExperimental_Part%2FExercise_Sheets&files=ES1_relativity.pdf