# Strong Coupling Constant from the Photon Structure Function

- Institution: CERN
- Department: CERN EP Seminar (up to 2008)
- Speaker: Simon Albino (Institut fuer Theoretische Physik, Universität Hamburg),
- Year: 2002
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3012345)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Teens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

We extract the value of the strong coupling constant alphas from a single-parameter pointlike fit to the photon structure function F2(gamma) at large x and Q2 and from a first five-parameter full (pointlike and hadronic) fit to the complete F2(gamma) data set taken at PETRA, TRISTAN, and LEP. In next-to-leading order and the MSbar renormalization and factorization schemes, we obtain alphas (mZ) = 0.1183 ± 0.0050 (exp.) +0.0029/-0.0028 (theor.) \[pointlike\] and alphas (mZ) = 0.1198 ± 0.0028 (exp.) +0.0034/-0.0046 (theor.) \[pointlike and hadronic\]. We demonstrate that the data taken at LEP have reduced the experimental error by about a factor of two, so that a competitive determination of alphas from F2(gamma) is now possible.

Organiser(s): Ariane FREY / EP Division

Note: Tea and coffee will be served at 15:00 hrs.

Please note unusual day and place.

## Lectures

1. [Strong Coupling Constant from the Photon Structure Function](https://invisiblenetwork.ai/learn/cern/3012345/f1a5fcd9f65d), 45 min (CERN's player)