Frank L. H. Wolfs
Department of Physics and Astronomy, University of Rochester
T0 Vertex Studies
¥How can we explain this?

¥Bug in software when T0 event is created? 
¥Not very likely since it was written by a Dutchman, but investigated anyway by looking at the raw FB data.  Correlations are also clearly visible in these data.

¥Effect of magnetic field?
¥No; runs with no magnetic field show the same effect.

¥Conclusion: this is a real effect.