- #1
ChrisVer
Gold Member
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I have one question, when should someone use rapidity [itex]y= 0.5 \ln \frac{E + p_z}{E - p_z}[/itex] and when pseudorapidity [itex]\eta = -\frac{1}{2} \ln \tan \theta/2[/itex]?
I've read that rapidity is used for "massive" particles... for experiments like LHC (or more specifically ATLAS), what threshold is considered massive?
I am sure that tau leptons (~1.7GeV) are not considered massive... however I recently read that for particles like J/ψ they use the rapidity... https://arxiv.org/abs/1104.3038
I've read that rapidity is used for "massive" particles... for experiments like LHC (or more specifically ATLAS), what threshold is considered massive?
I am sure that tau leptons (~1.7GeV) are not considered massive... however I recently read that for particles like J/ψ they use the rapidity... https://arxiv.org/abs/1104.3038