Data Types and Sources.
T2K raw data comprises “digits” for each of the detector elements, which are stored by the data acquisition in a binary format. The raw binary files are not readable except by T2K internal code and require separate channel mapping tables and calibration constants to reconstruct into data corresponding to physics objects (like particle momenta). Reconstructed physics objects are used to produce data-set level quantities, like measured oscillation parameters and neutrino interactions cross sections, which are published in peer-reviewed journals. T2K produces publicly available digital data-releases along with each published result.
Content and Format.
The format of the reconstructed (event level) data is that of CERN’s ROOT but requires T2K code to fully access and interpret. The data set level quantities use internal T2K code. The required T2K code is proprietary. All of the raw, reconstructed, and physics data together with the code required for analysis are stored on Grid computing. The full reconstructed data set and code will be preserved for a period of time following the completion of the experiment, the period of time to be decided by the T2K collaboration in consultation with funding agencies and the larger scientific community.
Sharing and Preservation.
T2K has been running for five years, so it has a well-exercised data distribution network which features multiple archives of the data, metadata, and essential software, preserving them in multiple copies on three continents and leaving any serious loss of data extremely unlikely.
The T2K collaboration views the collected data as a public asset and, to the extent that it is practical, makes it available. Due to the complexity of event level data general access is not practical. All published results are accompanied by public data-releases, which are available on T2K’s public web page. Without the specific consent and collaboration of T2K, access is only provided to the publicly available data-release. Any use of T2K data releases or associated work must acknowledge the T2K collaboration and appropriate funding agencies. All published figures and data tables will be freely and publicly available.
T2K data do not contain any personal identifiable or other confidential information, and therefore do not require special security measures to protect confidentiality.
This data management plan is in line with current practices of large particle physics experiments.