scattering theory In mathematics and physics, scattering theory is a framework for studying and understanding the scattering of waves and particles. Wave scattering corresponds to the collision and scattering of a wave with some material object, for instance sunli ...

and

accelerator physics Accelerator physics is a branch of applied physics, concerned with designing, building and operating particle accelerators. As such, it can be described as the study of motion, manipulation and observation of relativistic charged particle beams ...

, luminosity (''L'') is the ratio of the number of

events Event may refer to: Gatherings of people * Ceremony, an event of ritual significance, performed on a special occasion * Convention (meeting), a gathering of individuals engaged in some common interest * Event management, the organization of ev ...

detected (''dN'') in a certain period of time (''dt'') to the cross-section (''σ''): :

L = \frac\frac.

It has the dimensions of events per time per area, and is usually expressed in the cgs units of cm⁻²· s⁻¹ or the non-SI units of b⁻¹·s⁻¹. In practice, ''L'' is dependent on the particle beam parameters, such as beam width and particle flow rate, as well as the target properties, such as target size and density. A related quantity is integrated luminosity (''L''_int), which is the

integral In mathematics Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. These topics are represented i ...

of the luminosity with respect to time: :

L_\mathrm = \int L \ dt.

The luminosity and integrated luminosity are useful values to characterize the performance of a

particle accelerator A particle accelerator is a machine that uses electromagnetic fields to propel charged particles to very high speeds and energies, and to contain them in well-defined beams. Large accelerators are used for fundamental research in particle ...

. In particular, all collider experiments aim to maximize their integrated luminosities, as the higher the integrated luminosity, the more data is available to analyze.

Examples of collider luminosity

Here are a few examples of the luminosity of certain accelerators.

References

Accelerator physics Scattering theory