Terminology of rho electroproduction

[soxcited]

Dear Forum,

I am trying to learn more about the electroproduction of rho meson off proton.
e + p -> e + p + rho

One of the commonly used kinematic variable is tprime, defined as t-tmin.

The definition I could find for tmin is that it is the minimal value of t kinematically
necessary to put rho and proton system on shell.

However I still do not know how it is calculated and what does 'putting the system
on shell' mean. More explanation will be greatly appreciated. Thanks for any response
you might have.

 

[malawi_glenn]

on shell means that the particles beeing produced are real particles.

 

[sir-pinski]

Dear ,

Thank you for your question about the terminology of rho electroproduction. To better understand the concept of tprime and tmin, it is important to have a basic understanding of the kinematics involved in the process.

In the electroproduction of rho meson off a proton, a high-energy electron is scattered off a proton, resulting in the production of a rho meson. The momentum transfer between the electron and the proton is denoted by the variable t, which is defined as the square of the four-momentum of the exchanged virtual photon. This variable t is commonly used in particle physics to describe the scattering angle and energy transfer in a scattering process.

Now, tprime is defined as t-tmin, where tmin is the minimum value of t that is required to put the rho and proton system "on shell." In other words, tmin is the minimum value of t that is necessary for the particles to interact and produce a rho meson with the proton. This can also be understood as the minimum momentum transfer required for the particles to be in an energy state that allows for the production of a rho meson.

The calculation of tmin involves using the conservation of energy and momentum in the interaction. By considering the mass and energy of the particles involved, the minimum value of t can be determined. This value is then subtracted from the actual value of t to obtain tprime.

I hope this explanation helps clarify the terminology and concept of tprime and tmin in the electroproduction of rho meson off a proton. If you have any further questions, please do not hesitate to ask.