# Collider Parameters: corrected time for wrong vertex

1. Aug 30, 2012

### charlemagne94

Hello,

I stumbled across the following equation in a presentation about collider physics:

tcorrWV =(tiRV - tiWV) + (TOFRV - TOFWV),

where tcorrWV is the corrected time for the wrong vertex, tiRV is the initial time of the right vertex, tiRV is the initial time of the wrong vertex, TOFRV is the time of flight from the right vertex, and TOFWV is the time of flight from the wrong vertex.

I believe that tiRV is equal to zero by default, and the time of flight terms can be easily calculated from the kinematics of the collision. But I do not know what tiWV is.

Could someone familiar with collider physics elucidate the meaning of tiWV?

Thanks!

Edit: the presentation can be found at www-cdf.fnal.gov/~dcruz/DanielMasters.pptx
The equation in question is on slide 13.

Last edited: Aug 30, 2012
2. Aug 31, 2012

### Staff: Mentor

I think tiWV alone is not an interesting quantity - it is better to look at the difference (tiRV - tiWV): The collisions do not occur all at the same time, as the bunch length is finite (I think something like 10cm or .3ns at the LHC, probably similar for the Tevatron). The time difference between those collisions (average 0, but with some width) is relevant for the width of the background shown in slide 12.