Measurement of the angular distribution in $\bar p p\to ψ(2S)\to e^+e^-$

Details Measurement of the angular distribution in $\bar p p\to ψ(2S)\to e^+e^-$ Measurement of the angular distribution in $\bar p p\to ψ(2S)\to e^+e^-$

2004-12-01

arxiv.org/abs/hep-ex/0412007v2

Phys.Lett.B610:177-182,2005

Physics

High Energy Physics

High Energy Physics - Experiment

Accepted by Phys. Lett. B

Scientific paper

10.1016/j.physletb.2005.01.093

We present the first measurement of the angular distribution for the exclusive process $\bar p p \to \psi(2S)\to e^+e^-$ based on a sample of 6844 events collected by the Fermilab E835 experiment. We find that the angular distribution is well described by the expected functional form $\frac{dN}{d\cos\theta^{*}}$ $\propto$ 1 + $\lambda \cos^{2}\theta^{*}$, where $\theta^{*}$ is the angle between the antiproton and the electron in the center of mass frame, with $\lambda$ = 0.67 $\pm$ 0.15 (stat.) $\pm$ 0.04 (sys.) The measured value for $\lambda$ implies a small but non zero $\psi(2S)$ helicity 0 formation amplitude in $\bar p p$, comparable to what is observed in $J/\psi$ decays to baryon pairs.

Affiliated with

Also associated with

No associations

Rating

Measurement of the angular distribution in $\bar p p\to ψ(2S)\to e^+e^-$ does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Measurement of the angular distribution in $\bar p p\to ψ(2S)\to e^+e^-$, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Measurement of the angular distribution in $\bar p p\to ψ(2S)\to e^+e^-$ will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-146502