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Some higgsless unified models of particle physics predict that the mass of longitudinally polarized W bosons and the mass of transversely polarized W bosons are different.

In those models, a difference in masses is also predicted to appear for the Z boson.

Is there a way that the existing data from the LHC, the LEP or the Tevatron can be used to check this prediction? Or maybe it has already been checked?

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Hi Clara, and welcome to Physics Stack Exchange! Excellent question :-) I'm not very familiar with the models you're talking about, so I could only speculate at an answer, but I do hope someone knowledgeable comes along to answer this. –  David Z Mar 11 '12 at 6:12
Please give a reference to ''Some higgsless unified models of particle physics predict'' –  Arnold Neumaier Mar 11 '12 at 11:10
It is hard enough to measure the mass of the W since there are always missing neutrals in its decay, so I would not expect an experiment to be easy. The Z is a different story and somebody might be intrigued to check polarisations versus mass. In any case if a large mass difference existed one would have seen a secondary peak when scanning the Z:hal.archives-ouvertes.fr/docs/00/00/82/46/PDF/… –  anna v Mar 11 '12 at 11:38
Anna, but polarization changes continuously, so one would expect a smooth superposition of Gaussians, not a secondary peak. To see two distinct peaks, one would need to separate exact longitudinal and exact transversal polarization only, leaving out all the intermediate orientations. Is that possible? –  Clara Mar 11 '12 at 11:50
If there were a large mass difference in the two polarizations it would show as a bump, since each individual Z would be of a specific polarization, fixed for that Z once produced. Take Z going to e+e-. It will have one specific pollarisation, it is a particle. –  anna v Mar 11 '12 at 13:31

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