Madspin doesn't generate decay events

Dear jack,

You are running in the mode “set spinmode onhsell” in that mode, the events are actually generated by madevent.
To have an idea of how fast/slow such generation is, you can do

Import model loop_sm_qcd_qed
Generate z > a a a [noborn=QED]
output
launch

If you run in debug mode, you will see which tools is used to compute the loop. In my case I have the following:
 === Survey statistics summary ===
combined statistics: 30m47s, Avg. ML timing = 33 ms, Min precision = 6.66e-07
   -> Stability { tot# : 15439 , UPS% : 5.12 , EPS# : 1 }
   -> Red. tools usage in % { CT_DP : 0.013 , Ninja_DP : 84.4 , CT_QP : 5.12 , COLLIER : 10.4 }

The 5% of the time that the code use CT_QP (Cuttools quadruple precision) is likely to represent close to 90% of the computing time.
This also means that if you do not have Collier installed it is likely that the generation of events take three times longer that what I observe on my computer.
(Since then those PS points will be evaluated by CT_QP instead).

On my 8 core machine, I have timing close to 1h for generating those 100 events, so several hours seems possible.

Cheers,

Olivier

> On 8 May 2017, at 15:17, Jack Bargemann <email address hidden> wrote:
>
> New question #631685 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/631685
>
> I am trying to decay particles with madspin. However, despite trying several times and waiting several hours each time, madspin will not progress past the output "INFO: generate 100 decay events for particle z"
>
> I am generating p p > z all, then decaying with madspin. The full output is reproduced below.
>
> Is this a bug? Is there anything I can do so that the code runs correctly?
>
> Thank you
>
> Generating 100 events with run name run_01
> survey run_01
> INFO: compile directory
> compile Source Directory
> Using random number seed offset = 21
> INFO: Running Survey
> Creating Jobs
> Working on SubProcesses
> INFO: P1_gq_zq
> INFO: P1_qq_zg
> INFO: Idle: 1, Running: 0, Completed: 1 [ current time: 15h54 ]
> INFO: Idle: 0, Running: 0, Completed: 2 [ 3.5s ]
> INFO: Idle: 0, Running: 0, Completed: 2 [ 3.5s ]
> INFO: End survey
> refine 100
> Creating Jobs
> INFO: Refine results to 100
> INFO: Generating 100.0 unweigthed events.
> INFO: Effective Luminosity 0.0208930744681 pb^-1
> INFO: need to improve 0 channels
> Current estimate of cross-section: 5743.53 +- 33.2202088705
> P1_gq_zq
> P1_qq_zg
> INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 15h54 ]
> INFO: Combining runs
> INFO: finish refine
> refine 100
> Creating Jobs
> INFO: Refine results to 100
> INFO: Generating 100.0 unweigthed events.
> INFO: Effective Luminosity 0.0208930744681 pb^-1
> INFO: need to improve 0 channels
> Current estimate of cross-section: 5743.53 +- 33.2202088705
> P1_gq_zq
> P1_qq_zg
> INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 15h54 ]
> INFO: Combining runs
> INFO: finish refine
> combine_events
> INFO: Combining Events
> === Results Summary for run: run_01 tag: tag_1 ===
>
> Cross-section : 5744 +- 33.22 pb
> Nb of events : 100
>
> INFO: Creating Plots for parton level
> INFO: Plots for parton level generated, see /home/jack/Downloads/MG5_aMC_v2_4_2/bin/testing/HTML/run_01/plots_parton.html
> INFO: End Plots for parton level
> store_events
> INFO: Storing parton level results
> INFO: End Parton
> reweight -from_cards
> decay_events -from_cards
> INFO: Running MadSpin
> INFO: This functionality allows for the decay of resonances
> INFO: in a .lhe file, keeping track of the spin correlation effets.
> INFO: BE AWARE OF THE CURRENT LIMITATIONS:
> INFO: (1) Only a succession of 2 body decay are currently allowed
> ************************************************************
> * *
> * W E L C O M E to M A D S P I N *
> * *
> ************************************************************
> INFO: Extracting the banner ...
> INFO: process: p p > z all
> INFO: options:
> INFO: detected model: sm. Loading...
> set spinmode none
> set max_weight_ps_point 400 # number of PS to estimate the maximum for each event
> decay t > w+ b, w+ > all all
> decay t~ > w- b~, w- > all all
> decay w+ > all all
> decay w- > all all
> decay z > a a a [noborn=QED]
> launch
> INFO: Will use seed 829446144
> INFO: generate 100 decay event for particle z
>
> --
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