(present: AA, TH, TI, RK, ML)

Richard and Tayfun have been looking at the spacial response of the EMEC using electron runs. In particular the y-position (which they get from layer 1) and the x and phi position (in layer 2). They have started with small 3x3 (9 cells in each layer) event-by-event clusters and reconstructed the position. They required the energy to be above 2 sigma. The results showed that a 3x3 cluster is too small for EMEC layer1 (L1) since cell size in y is about 6.5 mm. The slides for layer1 can be found here. Theoretically, assuming 2Xo material in front of EMEC, the radial shower size in the middle of the L1 is ~ 3 cm in diameter for a 95% containment; ~ 10 cm in the middle of L2 and ~ 18 cm in the middle of L3. They have increased the size of the cluster in L1 to 5x3, 7x3, 9x3 and 11x3. The results were improved dramatically. The slides for 11x3 size cluster in L1 are here and the effect of increasing the size of the cluster on the position resolution can be seen here. The result for layer2 was reasonably fine with a 3x3 cluster. Further improvements to be made. One of which will be using a fraction of the energy (i.e. E^1/3) when finding the reconstructed position.
Michel suggested that the noise cut should perhaps be made on the absolute value of the signal.

Tamara has been looking at pion runs in both HEC and EMEC. She is working on finalizing the list of cells for her pion reconstruction studies. An occupancy cut and a topological cut are used to determine the cluster. Eventually, the plan is to fix the cluster size for all runs at the same impact point so that the amonut of the noise is the same for all of them. She used the number of cells to watch the change of the cluster size, but found out that it is not a good idea because the number of cells changes dramatically for different energies, especially due to the fact that the cells in layer1 of EMEC has a very small size in y-direction. They are now investigating volume as a possible measure.
Tamara has showed some plots of energy weighted widths of the average shower in x and in y for different beam energies. Since the average energy per channel is used as weight, this gives the x and y width of the average shower envelope, over a whole run, which is not the same as the actual event by event shower width.
Tamara also finds that the energy weighted center of the shower is not the same as occupancy weighted center of the shower, which is not surprising.

Finally, there was some discussion about the NIM paper. Alan pointed out that what was in the INTAS document was probably appropriate for a NIM paper, and all agreed. It was felt that we could still possibly contribute with the current work.