ɪn pɹˈæktɪs, pˈɑːɹɾɪkəlz wɪð sˌuːdoʊɹɐpˈɪdᵻɾi əbˌʌv ɐ sˈɜːʔn̩ θɹˈɛʃoʊld kænˈɑːt biː mˈɛʒɚd sˈɪns ðeɪ ɑːɹ tˈuː nˌɪɹli pˈæɹəlˌɛl tə ðə bˈiːmlaɪn ænd kæn ðˈʌs pˈæs θɹuː ðə dɪtˈɛktɚ.
In practice, particles with pseudorapidity above a certain threshold cannot be measured since they are too nearly parallel to the beamline and can thus pass through the detector.