bˌʌt ðə dɪzˈaɪɚd ᵻvˈɛnts ɑːɹ mˈɪkst ˌʌp wɪð ɐ sɪɡnˈɪfɪkənt nˈʌmbɚɹ ʌv ˈʌðɚɹ ᵻvˈɛnts, pɹədˈuːst baɪ ˈʌðɚ pˈɑːɹɾɪkəlz ɔːɹ pɹˈɑːsɛsᵻz, wˌɪtʃ kɹiːˈeɪt ˌɪndɪstˈɪŋɡwɪʃəbəl ᵻvˈɛnts ɪnðə dɪtˈɛktɚ.
But the desired events are mixed up with a significant number of other events, produced by other particles or processes, which create indistinguishable events in the detector.