1. Status report from T2K-SK group Task list of this group discussion about NEUT Kaneyuki, Walter, Konaka We have just started the discussion.

2. T2K-SK group T2K-SK group consists of following two groups; SK members on T2K who will do SK calibration and process and prepare SK-DST (JHFnu-SK sub-group in SK-JHFnu agreement) Both SK and non-SK members who will perform the SK data analysis

3. Task list of T2K-SK group SK-DST related SW trigger, reduction, reconstruction, calibration, quality monitor, DST, calibration constants, ntuple MC neutrino interaction, detector simulation for new electronics Documentation In this work, we need help from both SK and non-SK collaborator. First, we would like to ask to non-SK collaborator what kind of documents do you need ? (Everything is too huge jobs.) SK analysis basic strategy  dis-apperance e appearance others We have just started the discussion. We heard opinions from SK experts about these topics, first.

4. SK-DST related DST: – ROOT or ZEBRA based file for ±500micro second around beam timing. – calibration constants will be applied. – SW trigger: to save all hit information (T and Q) – reduction: hit sum like trigger + low energy cut ? – w/ standard reconstruction (trigger timing of event, vertex, number of ring, PID, momentum etc.) w/o e/  0 separation ?

5. neutrino interaction model The current default neutrino interaction generator for SK is NEUT. We should use same neutrino interaction generator for ND and FD (SK) on the oscillation analysis. So, we discussed with Hayato_san who is in charge of NEUT in SK. NEUT source code can be available to the T2K collaboration. (see next slide) event generator part is separated from flux in NEUT. NEUT can only work with one nucleus (and hydrogen) at a time. Work is needed to make it work for multiple nucleus. NEUT support ROOT output, but the format is different from GENIE format.

6. Proposal to SK collaboration by Hayato (accepted) (SK collaboration meeting on 10/Nov/2007) T2K collaborators started to study their detector and want to use neut. 1)Neut is provided as a single tarball (neut.tar.gz). Not by CVS or other revision control system for the T2K collaborators for a moment. ( Until we have a standalone repository server for the T2K experiment. ) 2)We will prepare an e-mail address to receive feedbacks from the T2K members If they find some problems, bugs, or make improvements, send e-mails to this e-mail address. 3)It is not allowed to re-distribute the neut library. Some people want to use neut with the other simulation programs. In such a case, we would like to ask them to prepare interface functions. We don’t want the neut functions to be included in their program libraries. Now neut is separated from the other SK libraries. Therefore, it is possible to distribute the neut library alone.

7. How to use NEUT in ND280 ND280 is using GENIE. NEUT has been tested and used extensively on SK detector, and thus default event generator for oscillation study is NEUT. For detailed neutrino cross section studies in ND280, there is some desire to have flexibility to compare cross section models and fit parameters, like GENIE So, we have two option, using vector based on NEUT, implementing NEUT algorithm into GENIE. Primary neutrino interaction of NEUT can already be reproduced in GENIE but it uses different algorithm for nuclear effect from NEUT (nuclear cascade). Costas_san is the primary contact of GENIE and he is a T2K collaborator. He proposes to integrate NEUT cascade code into GENIE, or interface GENIE to it as if it is an external product. He proposes to have a face-to-face meeting on this task at the next T2K collaboration meeting. (This part is the item that goes beyond the boundary of T2K-SK group.)

8. T2K-SK group have just started the work. NEUT will be available at source code level. We need help by SK and non-SK collaborator for documentation. We will have a face-to-face meeting at Vancouver next week to discuss each topics.