METS scale setter inquiry

[Wojciech.Kotlarski@fuw.edu.pl]

Dear Sherpa authors,

When running attached setup for pp>ttbarZ production in 4 flavor scheme with EXCLUSIVE_CLUSTER_MODE=1 I get an error message

Process_Group::CalculateTotalXSec(): Calculate xs for '2_5jjZttbbbb' (Comix) Starting the calculation at 06:21:41. Lean back and enjoy ... . 0.000275226 pb +- ( 4.40448e-05 pb = 16.0031 % ) 5000 ( 11731 -> 42.6 % ) full optimization: ( 1m 21s (1m 16s) elapsed / 1h 59m 56s (1h 53m 20s) left ) [06:23:02] METS_Scale_Setter::Calculate(): No CSS history for '2_5ddbZttbbbb' in >100% of calls. Set \hat{s}. METS_Scale_Setter::Calculate(): No CSS history for '2_5dbdZttbbbb' in >100% of calls. Set \hat{s}. METS_Scale_Setter::Calculate(): No CSS history for '2_5uubZttbbbb' in >100% of calls. Set \hat{s}. METS_Scale_Setter::Calculate(): No CSS history for '2_5ubuZttbbbb' in >100% of calls. Set \hat{s}. 0.000229427 pb +- ( 2.41045e-05 pb = 10.5064 % ) 10000 ( 22565 -> 46.1 % ) full optimization: ( 2m 40s (2m 33s) elapsed / 1h 57m 24s (1h 52m) left ) [06:24:21] 0.000222196 pb +- ( 1.68969e-05 pb = 7.60451 % ) 15000 ( 33749 -> 44.7 % ) full optimization: ( 3m 59s (3m 49s) elapsed / 1h 55m 17s (1h 50m 44s) left ) [06:25:40] 0.000204953 pb +- ( 9.56979e-06 pb = 4.66926 % ) 20000 ( 45326 -> 43.1 % ) full optimization: ( 5m 17s (5m 5s) elapsed / 1h 53m 42s (1h 49m 29s) left ) [06:26:59] 0.00020181 pb +- ( 7.25193e-06 pb = 3.59345 % ) 25000 ( 56683 -> 44 % ) full optimization: ( 6m 37s (6m 22s) elapsed / 1h 52m 35s (1h 48m 12s) left ) [06:28:19] 0.000204692 pb +- ( 6.17495e-06 pb = 3.0167 % ) 30000 ( 68176 -> 43.5 % ) full optimization: ( 7m 58s (7m 38s) elapsed / 1h 51m 27s (1h 46m 58s) left ) [06:29:39] 0.000211643 pb +- ( 4.50886e-06 pb = 2.1304 % ) 45000 ( 102193 -> 44 % ) full optimization: ( 11m 55s (11m 27s) elapsed / 1h 47m 14s (1h 43m 4s) left ) [06:33:36] 0.000213023 pb +- ( 3.66265e-06 pb = 1.71937 % ) 60000 ( 136936 -> 43.1 % ) full optimization: ( 15m 50s (15m 16s) elapsed / 1h 42m 58s (1h 39m 12s) left ) [06:37:32] 0.000211493 pb +- ( 3.01214e-06 pb = 1.42423 % ) 75000 ( 171742 -> 43 % ) full optimization: ( 19m 46s (19m 4s) elapsed / 1h 38m 52s (1h 35m 20s) left ) [06:41:28] 0.000213925 pb +- ( 2.64823e-06 pb = 1.23792 % ) 90000 ( 208362 -> 40.9 % ) full optimization: ( 23m 41s (22m 53s) elapsed / 1h 34m 46s (1h 31m 30s) left ) [06:45:23] 0.000213861 pb +- ( 2.47769e-06 pb = 1.15855 % ) 105000 ( 247031 -> 38.7 % ) full optimization: ( 27m 42s (26m 44s) elapsed / 1h 31m 1s (1h 27m 50s) left ) [06:49:23] 0.000214449 pb +- ( 2.24109e-06 pb = 1.04505 % ) 120000 ( 284438 -> 40 % ) full optimization: ( 31m 41s (30m 35s) elapsed / 1h 27m 9s (1h 24m 8s) left ) [06:53:23] 0.000212481 pb +- ( 2.01012e-06 pb = 0.946023 % ) 135000 ( 321440 -> 40.5 % ) full optimization: ( 35m 40s (34m 27s) elapsed / 1h 23m 14s (1h 20m 22s) left ) [06:57:21] 0.000211999 pb +- ( 1.86113e-06 pb = 0.877896 % ) 150000 ( 357758 -> 41.3 % ) full optimization: ( 39m 41s (38m 18s) elapsed / 1h 19m 21s (1h 16m 36s) left ) [07:01:22] 0.000211981 pb +- ( 1.74013e-06 pb = 0.820893 % ) 165000 ( 394127 -> 41.2 % ) full optimization: ( 43m 40s (42m 9s) elapsed / 1h 15m 25s (1h 12m 49s) left ) [07:05:21] 0.000211672 pb +- ( 1.65904e-06 pb = 0.783775 % ) 180000 ( 430217 -> 41.5 % ) full optimization: ( 47m 41s (46m 1s) elapsed / 1h 11m 31s (1h 9m 1s) left ) [07:09:22] 0.000211516 pb +- ( 1.58715e-06 pb = 0.750368 % ) 195000 ( 466107 -> 41.7 % ) full optimization: ( 51m 40s (49m 52s) elapsed / 1h 7m 34s (1h 5m 13s) left ) [07:13:21] 0.000211933 pb +- ( 1.51295e-06 pb = 0.713878 % ) 210000 ( 502072 -> 41.7 % ) full optimization: ( 55m 40s (53m 44s) elapsed / 1h 3m 37s (1h 1m 25s) left ) [07:17:21] 0.00021153 pb +- ( 1.44281e-06 pb = 0.68208 % ) 225000 ( 536851 -> 43.1 % ) full optimization: ( 59m 39s (57m 36s) elapsed / 59m 40s (57m 36s) left ) [07:21:20] 0.000211401 pb +- ( 1.39696e-06 pb = 0.66081 % ) 240000 ( 571480 -> 43.3 % ) full optimization: ( 1h 3m 40s (1h 1m 28s) elapsed / 55m 42s (53m 47s) left ) [07:25:21] 0.000211588 pb +- ( 1.34458e-06 pb = 0.635472 % ) 255000 ( 606435 -> 42.9 % ) full optimization: ( 1h 7m 40s (1h 5m 20s) elapsed / 51m 45s (49m 57s) left ) [07:29:21] 0.000211769 pb +- ( 1.30494e-06 pb = 0.616212 % ) 270000 ( 641256 -> 43 % ) full optimization: ( 1h 11m 38s (1h 9m 12s) elapsed / 47m 45s (46m 9s) left ) [07:33:19] 0.000211655 pb +- ( 1.27004e-06 pb = 0.600053 % ) 285000 ( 675917 -> 43.2 % ) full optimization: ( 1h 15m 37s (1h 13m 5s) elapsed / 43m 47s (42m 18s) left ) [07:37:18] 0.000211416 pb +- ( 1.22961e-06 pb = 0.581607 % ) 300000 ( 710530 -> 43.3 % ) full optimization: ( 1h 19m 39s (1h 16m 57s) elapsed / 39m 50s (38m 29s) left ) [07:41:20] 0.000211374 pb +- ( 1.20163e-06 pb = 0.568485 % ) 315000 ( 744252 -> 44.4 % ) full optimization: ( 1h 23m 47s (1h 20m 50s) elapsed / 35m 54s (34m 38s) left ) [07:45:28] 0.00021139 pb +- ( 1.13046e-06 pb = 0.534776 % ) 360000 ( 845728 -> 44.3 % ) integration time: ( 1h 35m 48s (1h 32m 27s) elapsed / 23m 57s (23m 7s) left ) [07:57:29] 0.000211679 pb +- ( 1.08746e-06 pb = 0.513731 % ) 390000 ( 912891 -> 44.4 % ) integration time: ( 1h 43m 53s (1h 40m 12s) elapsed / 15m 59s (15m 25s) left ) [08:05:34] 0.000211655 pb +- ( 1.04522e-06 pb = 0.493829 % ) 420000 ( 980087 -> 44.5 % ) integration time: ( 1h 51m 54s (1h 47m 56s) elapsed / 7m 59s (7m 43s) left ) [08:13:35] 0.000211443 pb +- ( 1.00279e-06 pb = 0.474261 % ) 450000 ( 1047452 -> 44.5 % ) integration time: ( 1h 59m 56s (1h 55m 41s) elapsed / 0s (0s) left ) [08:21:36] 2_5jjZttbbbb : 0.000211443 pb +- ( 1.00279e-06 pb = 0.474261 % ) exp. eff: 0.187117 %

reduce max for 2_5jjZttbbbb to 0.724637 ( eps = 0.001 )

As I understand this indicates that SHERPA cannot invert parton branching to get lowest multiplicity configuration. What I don't understand is whether this indicates that something went really wrong and the result is unreliable or not? The second thing is the question about METS scale setter in case of this process. This process will not be clustered into 2 to 2 configuration. Do you need to define explicitly scale of the lowest multiplicity configuration by CORE_SCALE switch or can you leave it blank?

thanks in advance, Wojciech

[Wojciech.Kotlarski@fuw.edu.pl]

ttbarZ run card