Example

This example might help you to analyse your results.



The following table shows you the most important W production processes that may take place. The W production processes of quark gluon interactions are displayed in the first row and those of gluon gluon interactions in the second row. Processes in which a W+ particle can be produced are shown in the first column whereas the second column contains the processes of W- production.

Interaction process W+ W-
Quark gluon interaction
Gluon gluon interaction


Now, we'll add information given by the theory and the example of one measurement to that table in order to calculate individual contributions of the processes that produce W particles.

From theory (see hint 1) we know, that 66% of the W particles are produced in quark gluon interactions and 34% in gluon gluon interactions. We also stipulate one possible result of the measurement: 55% W+, 45% W-:

Interaction process W+ W- theory
Quark gluon interaction 66%
Gluon gluon interaction 34%
measurement 55% 45% 100%


Theoretical predictions (see hint 2) help us to calculate the contributions of the individual gluon gluon interactions since both processes happen with the same rate:

Interaction process W+ W- theory
Quark gluon interaction 66%
Gluon gluon interaction : 17% : 17% 34%
measurement 55% 45% 100%


The last two missing proportions can now be easily calculated by building the sum of both columns:

Interaction process W+ W- theory
Quark gluon interaction : 38% : 28% 66%
Gluon gluon interaction : 17% : 17% 34%
measurement 55% 45% 100%


For the chosen example the ratio of W+ to W- (both produced in quark gluon interactions) is 38:28, or simply 1.4.

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