28 April 2017

Browsing the nucleon-nucleon database:
input options

This page gives some information and hints how to use the form for searching the database of nucleon-nucleon scattering data.
The form contains several options for browsing the database. Apart from the type of reaction (pp or np) there is no obligation to make any selection; no further selection will result in rendering the complete database (references and some essential characteristics). There is also no restriction on the number of selections. And finally: searches are case-insensitive.

A short description of the selection options:

Reaction This is compulsory; make a choice between proton-proton or neutron-proton data.
Database You can choose whether or not you wish to browse only the database of published data, unpublished data, or both. As our policy in PWA's is not to include unpublished data, this section may be deceptively empty, or surpisingly full....
Publication year The database contains all data published in regular journals between 1955 and today. You can select for measurements of data published in a specified range of years. You can use 4-digit years as well as 2-digit years. In the latter case the program tries to figure out itself which century you intended.
Energy The database contains all data with Tlab between 0 and roughly 3 GeV.
Most of the groups of data contain data at a single energy; sometimes a group may consist of data at multiple energies. In the latter case, a search on Tlab means that the group of data covers (completely or partially) the energy region you specified. It does NOT necessarily mean that the group actually contains data in that energy region!
CM scattering angle You can choose for experiments that cover measurements in a specified angular range. Angles are center-of-mass scattering angles between 0 and 180 degrees.
The selection of an angular range means that the selected groups of data cover completely or partially the specified angular range. It does NOT necessarily mean that the selected groups of data actually contain data in that range!
This selection naturally does not work for total cross-section data: A selection on angular range immediately implies filtering out these kind of observables.
Observable One can choose for a measurements of a particular type of observable. There is a short list from which you can choose, and there is an inputfield.
From the list you can select one observable at a time; it contains some of the most occurring observables; if you wish other observables you can use the text-input.
At the textinputfield you can choose upto five observables at the same time; list them separated with comma's. For example: axx,ayy,azz to select all these observables. It is also possible, by putting a minus sign in front of the list to select all observables apart from the listed ones. For example: -dsg will return all observables except for differential cross-sections.
If you have selected from the list as well as given something in the inputfield, then only the latter is used!
Reference Each set of data contains a reference to where the data are published. These options make it possible to select for specific experiments or publications:
The database contains at least the first author of the reference; other authors may or may not be included. A future version of the database will have all authors of a paper included.
This is a 6-character code:
  • The first two characters are the first 2 letters of the name of the first author.
  • The second two characters give the year of publication
  • The last two characters are only used when two (or more) references would have the same code.
LA65 :
Langsford et al. Nuc. Phys. 74(1965)241 (Harwell)
There is no need to supply a complete code; it's just a string search in the list of all available codes.
Laboratory The database contains an entry that gives the laboratory or institute where the experiment has been performed.
LA65 :
Langsford et al. Nuc. Phys. 74 (1965), 241 (Harwell)
There is no need to supply a complete name; it's just a string-search in the list of all laboratories. Not all groups of data have a lab-entry yet, and many entries may be incorrect!!! 28 April 2017