# What is QCD sum rule(s)?

1. Aug 28, 2006

### BuckeyePhysicist

What is QCD sum rule(s)?

2. Aug 28, 2006

### Meir Achuz

A QCD sum rule is an integral, usually from x=0 to x=1(Bjorken), of something (e.g. spin projection), Usually some PQCD conjecture implies a particular value for the integral. One difficulty is getting to x=0 experimentally. Another is what corrections to the conjecture do to the sum rule.