Hlt1 Calo DiCluster Line

Implements dicluster reconstruction from pairs of calo clusters.

Includes a dicluster line in the hlt1_pp_default sequence aimed at Bs2GammaGamma decays. Diclusters are selected based on the dicluster's mass and Et, clusters' Et and SumEt.

Adds a mechanism to the clustering algorithm that checks if the cluster's seed cell has track matching.

Slides with plots with MB and Bs2GammaGamma simulation Allen_TwoCluster.pdf (Needs updating following a bug fix in calo_seed_clusters)

To do list:

• Include n_diclusters in the monitoring tuple
• Replace SumEt by Et and include clusters Et in twocluster object
• For twoclusters line, include cuts on twocluster and clusters Et
• Include cut on number of PVs for twoclusters line Check follow up issue #341 (closed)
• Tune selection requirements (e.g., minimum distance between two clusters)
• Study number of two clusters per event to define better the maximum output size Calo::Constants::max_ndiclusters

Old slides with plots before fixes kept for historical reasons Allen_TwoCluster.pdf

Needs MooreOnline!97 (closed)

Throughput Loss

Bs2GammaGamma represents the current state of the MR, with only the dicluster selection running. This implies running the cluster reconstruction and the dicluster combinatorics.

SingleCaloCluster represents a configuration in which the Bs2GammaGamma line is replaced by the Hlt1SingleCaloCluster line from hlt1_cosmics. In this case, the dicluster algorithms are not executed.

Finally, Both represents a configuration where both lines are executed.

Comparing Bs2GammaGamma and Both indicates that the selection itself is not relevant for the throughput. Then, comparing Bs2GammaGamma and SingleCaloCluster indicates that the calo cluster reconstruction causes the most relevant drop in throughput. I believe this is corroborated by the sequence breakdown, which shows calo_seed_clusters (first step in the calo cluster reconstruction) as the most important contribution from the new calo algorithms (3.84%).

Edit: These throughput numbers are outdated. The current tests show a throughput loss of about 3%.