Mock Data (MDS)

MDC 2024: Mock Data samples

Introduction

Mock data samples can be helpful in two ways:

• to help prepare physics analysis efforts;
• to help us understand the size of our data .art files and ntuples.

Streams

The two purposes above (physics studies, trigger studies) will result in different samples, with differing complexity.

Physics stream

Includes all major components and pile-up. The DIOtail momentum cut can be higher (nominally p>95 MeV/c will be used as a starting point). Three samples will be made: signal at just below current limit (1e-13), closed sample (random signal choice), no signal.

Trigger stream

Here all backgrounds and pile-up will be included but no signal. The DIOtail cut is reduced below the trigger threshold to p > 75 MeV/c.

Inputs

There are several assumptions made when we choose a livetime:

Booster Batch Mode

The Booster Batch (BB) mode describes the incoming operational mode of the booster which feeds the beam through our delivery ring which in turn passes protons to Mu2e.

There are two "run modes" in Mu2e: 1BB and 2BB, in the low-intensity running mode the mean intensity is 1.6E7 protons/pulse and in the higher-intensity mode this becomes 3.9E7 protons/pulse.

Batch	Time (s)	T Cycle (s)	T Spill (s)	Spills	frac	On Spill Time	N-cycles	POT per cycle
1	9.52E+06	1.33	1.07E-01	4	0.323	3.07E+06	7.16E+06	4.00E+12
2	1.58E+06	1.4	4.31E-02	8	0.246	3.89E+05	1.13E+06	8.00E+12

Expected DIOs

The expected number of muon stops per POT is 1.56E-3 muons/POT (from MDC2020p). The decay : capture ratio for Al is 0.39:0.61.

In our simulation, we tend to focus on simulating the higher momentum tail with cuts of p > 75MeV/c sampling a fraction of 4.19E-07 of the entire DIO spectrum. and p > 95 MeV/c sampling a fraction of 3.64E-11 of the entire DIO spectrum.

livetime	BB	POT	Stopped Muons	DIOs (p>75MeV/c)	DIOs (p>95MeV/c)
1 hour	1BB	1.08E16	1.67e+13	7.10e6	609

Sim Efficiencies and Databases

One major improvement from the previous MDC2018 is that we now have database implementation in Mu2e. This includes a "SimEfficiency" data-base which can be used to extract the expected rates from the simulation, without need for hardcoding. Here is an example of how to extract the number of stopped muons per pot:

# get stopped rates from DB
dbtool = DbService.DbTool()
dbtool.init()
args=["print-run","--purpose","MDC2020_best","--version","v1_1","--run","1200","--table","SimEfficiencies2","--content"]
dbtool.setArgs(args)
dbtool.run()
rr = dbtool.getResult()
# get number of target muon stops:
target_stopped_mu_per_POT = 1.0
rate = 1.0
lines= rr.split("\n")
for line in lines:
    words = line.split(",")
    if words[0] == "MuminusStopsCat" or words[0] == "MuBeamCat" :
        #print(f"Including {words[0]} with rate {words[3]}")
        rate = rate * float(words[3])
        target_stopped_mu_per_POT = rate * 1000 
print(f"Final stops rate muon {target_stopped_mu_per_POT}")

Production Scripts

To automate parts of the process a number of scripts have been written. These reside in the Produciton repo: Production/ensembles.

There are a number of helper scripts available:

ensemble python scripts

• normalization.py - calculated normalization for each sample based on user assumptions
• maketemplatefcl.py - makes the SamplingInput fcl for the provided data set
• calculateEvents.py - prints number of a specific process events for chosen user inputs

ensemble shell scripts

• Stage1: the S1 script tells you the minimum number of events needed to match a chosen cosmic sample for each input process. The number of jobs for each input process must match the number of chosen cosmic files. You could simulate more than this to allow for failure modes, but only use that number of jobs in the eventual ensembling.

• Stage2: this script combines the input samples, the template fcl and passes these to the grid to run the parrallized ensembling using the standard Mu2e grid tools.

Components

DIO tail

The DIO tails is simulated from stopped muons using the SingleProcessGenerator defined in the Offline EventGenerator directory. The DIOGenerator tool is used to provide the correct momentum distribution based on the 5-8 polynomial derived by Czarnecki et al.

A filter called GenFilter is used to remove events unlikely to produce viable events in the reconstruction. The effect of the filter is to improve the time performance by 40%, there is no loss of efficiency.

Two DIO tail samples are included as primaries in two sets of samples for MDC2024: one has a cut at p > 95 MeV/c (a fraction of 3.64e-11 of the entire DIO momentum spectrum) and another has a lower cut, below the trigger threshold, of p > 75 MeV/c (a fraction of 4.19e-7 of the entire DIO spectrum).

In previous simulation studies, DIOs of all momenta are included in the pile-up stream and not as primaries, including them as primaries has the advantage of giving us a large sample of events and therefore increased realism.

Conversion and Conversion Leading Log

CeEndpoints are a standard part of production. The Leading Log camapign includes the leading log corrections calculated by Szfaron. This results in about 10% of electrons being in a lower momentum tail (as opposed to all being at 104.97 MeV/c in the case of the CeEndpoint).

Cosmics

As part of SU2020 a campaign that used the CORSIKA generator was built and exercised, providing 1.1e7s of cosmic events to be sampled from. Similarily a campaign of a similar size using the CRY generator is also available.

The CRY sample is used for pass 0, but the CORSIKA one is used for the later camapigns.

Pile-up

For pass 0 the existing pile-up streams were used. These were mixed with the combined primary sample as if it were any other primary sample.

This will provide some inaccuracies, as we are mixing in two DIO samples (one as a primary for p > 95 MeV/c and one which is part of the MuStopPileup sample and covers all momentum ranges up to the endpoint). This could introduce some double counting but it is unlikely to overly effect the outcomes of any physics analysis applied to these samples.

For future passes, custom pile-up samples will be combined as primaries in the same way we have done the DIO tails.

RPC

RPC is simulated using the RPCGun generator. Both internal and external RPC can be simulated using the same generator.

At timing filter on arrival proper time of the stopped pions is used to improve performance of the simulation. This must be factored in when normalizing the samples.

Input Samples

Here is a list of the relevant samples used as part of the current Mock Data effort.

The exact samples input into each MDS is mentioned below.

process	campaign	generated	reconstructed	livetime (s) (1BB)	POT equiv	eff
CosmicCORSIKA	MDC2020ae		9568173	1.1e7
DIOtailp95MeVc	MDC2024a_4	401760000	192315262	6032089213	1.81416E+22	0.478
DIOtailp75MeVc	MDC2024a_3	160000000	28887387	2.03E+05	6.11958E+17	0.180
DIOtail (95)	MDC2020ad	3267000	1534077	127960436.9	3.84843E+20	0.469
DIOtail (75)	MDC2020ad_sm0	170150000	30357435	2219329	6.67465E+17	0.178
CeEndpoint	MDC2020ac	100000	54280			0.542
CeMLeadingLog	MDC2024a_sm4	22400	11687			0.522

DIO 75MeV/c short tests

A set of very short samples with a p>75MeV/c cut on the DIO tail were generated to get a feel for the size and time taken to generate this sample. These are available for anyone testing the trigger, but not useful for physics studies. The larger DIOtail only sample can also be used as in all cases the eventual events were all DIOtails.

Tag	Processes	BB	equiv. time	equiv. POT	Rmue	conditions	Comments	sam name
testa	CE+DIO(75MeV/c)	1BB	17s	5.22e13	0	perfect	dts,dig,mcs	ensemble-1BB-CEDIO-60s-p75MeVc
testb	CE+DIO(75MeV/c)+CRY	1BB	17s	5.22e13	0	perfect	dts,dig,mcs	ensemble-1BB-CEDIOCRYCosmic-60s-p75MeVc
testc	CE+DIO(75MeV/c)	2BB	13s	7.7e13	0	perfect	dts,dig,mcs	ensemble-2BB-CEDIO-60s-p75MeVc
testd	CE+DIO(75MeV/c)+CRY	2BB	13s	7.7e13	0	perfect	dts,dig,mcs	ensemble-2BB-CEDIOCRYCosmic-60s-p75MeVc
teste	CE+DIO(75MeV/c)+CRY	1BB			0	perfect	dts only	ensemble-1BB-CEDIOCRYCosmic-3600s-p75MeVc
testf	CE+DIO(75MeV/c)+CRY+PU	1BB			0	perfect	dts only	ensembles-1BB-CEDIOCRYCosmic-60s-p75MeVc-OnSpillMix1BBTriggered

Mock-Dataset-0 (MDS0) (95 MeV/c)

The MDS0 samples all include DIO tail events with the 95 MeV/c cut. Two sample sizes are chosen: 1 week livetime and 1 month livetime.

All components except the RPC are included. Two Rmue values are used, one at 1e-13 which is just below the present upper limit (7e-13) and allows around 55 generated CE events for the 1 week sample and 222 generated CE for the 1 month livetime (before any selection or reconstruction efficiency is factored in).

The samples available are listed below:

Tag	Processes	BB	eqiv POT	equiv livetime	Rmue	conditions	sam name	Comments
MDS0a	CE+DIO(95MeV/c)	1BB	1.50e18	4.89E+05 (5.7days)	9.39E-14	best,perfect	nts.mu2e.MDS0a.MDC2020ad_perfect_v1_2.root
MDS0b	CE+DIO(95MeV/c)+CRY	1BB	5.61E+17	1.86E+05 (2.1 days)	1e-13	best,perfect	nts.mu2e.MDS0b.MDC2020ad_perfect_v1_3.root
MDS0c	CE+DIO(95MeV/c)+CRY	1BB	2.31E+18	7.70E+05 (8.9 days)	8.88E-14	best,perfect	ensemble-1BB-CEDIOCRYCosmic-2400000s-p95MeVc-Trigger-
MDS0d	CE+DIO(95MeV/c)+CRY+PU	1BB	5.84E+17	1.94E+05 (2.2 days)	1.35E-13	perfect	ensemble-1BB-CEDIOCRYCosmic-600000s-p95MeVcMix1BBTriggered	normalization somewhat handwavy here, expect similar to pass0b
MDS0e	CE+DIO(95MeV/c)+CRY	1BB			1e-13	perfect	dts only: ensemble-1BB-CEDIOCRYCosmic-31000000s-p95MeVc	largest simple sample

The dts, digi, mcs and TrkAna ntuples are available in the usual locations. In most cases the digi and reco stages were ran with perfect and best condtions.

The component samples which went into these streams are listed here:

process	tag	Comments
CeEndpoint	MDC2020ac
DIOtail (95MeV/c)	MDC2020ad
DIOtail (75MeV/c)	MDC2020ad_sm0
CRY Comsic	MDC2020s	1 year sample, signal stream
pile-up/stops	MDC2020p	most recently made mu beam sample

Yields

Before any cuts are applied the true values for each process can be derived using the Process Code:

tag	DIOtail	CE	Cosmics	Other
MDS0a	9966	49	N/A
MDS0b	3801	20	4684
MDS0c	15691	73	19101
MDS0d	3956	28	4681

Once a standard set of cuts is defined we will apply those and update these yields.

Effects of Pile-up

Samples pass0b and pass0d are essentially the same, in terms of physics contributions. However, pass0d contains standard pile up. Here is a list of the processess reconstructed in each file:

• Pass0b:

[(38, 'cosmicCRY', 4684)]
process code counts:
[(12, 'compt', 71), 
(13, 'conv', 882), 
(14, 'Decay', 181), 
(17, 'eIoni', 24), 
(31, 'muIoni', 2269), 
(34, 'muPairProd', 143), 
(56, 'mu2ePrimary', 4684), 
(97, 'neutronInelastic', 2), 
(99, 'pi_PlusInelastic', 1), 
(114, 'DIO', 7),
(116, 'muonNuclear', 4), 
(166, 'mu2eMuonDecayAtRest', 3801), 
(167, 'mu2eCeMinusEndpoint', 20)]

• Pass0d

(38, 'cosmicCRY', 4681)
process codes:
[(12, 'compt', 176),
(13, 'conv', 892), 
(14, 'Decay', 470),
(17, 'eIoni', 39),
(31, 'muIoni', 2285), 
(34, 'muPairProd', 139),
(56, 'mu2ePrimary', 4681),
(97, 'neutronInelastic', 1), 
(100, 'pi_MinusInelastic', 1), 
(114, 'DIO', 456),
(116, 'muonNuclear', 4), 
(133, 'RadioactiveDecayBase', 1),
(165, 'mu2eMuonCaptureAtRest', 4),
(166, 'mu2eMuonDecayAtRest', 3956), 
(167, 'mu2eCeMinusEndpoint', 28)

So, as you see, the total number of mu2eMuonDecayAtRest is similar, a slight increase in 0d. This could be a result of decays < the chosen cut but also there will be some chance of double counting in current PU model. Part of the goals moving forward is to remove that possibility. There are also a few more CeMinusEndpoints. Whether these would pass selection cuts is not known. We see an increase in compton events, Decay events and DIO (which includes Michel decays and DIFs). We see a small amount of capture backgrounds (4).

Mock Dataset 1 (MDS1)

MDS1 will inherit from the MDC2020ae (Cosmics) and MDC2024a_* releases and classified as MDC2024a.

Several updates are made for MDS 1:

• CeEndpoint now including the leading log too;
• DIO tail momentum cut moved to 75 MeV/c for triggered stream only;
• CORSIKA generator used for cosmics;
• PU streams upgraded (might move to pass2).

All will assume 1BB:

Tag	Processes	equiv livetime	Rmue
MDS1a	CELL+DIO(95MeV/c)+CORSIKA	~1 month	1e-13
MDS1b	CELL+DIO(95MeV/c)+CORSIKA	~1 month	1e-14
MDS1c	CELL+DIO(95MeV/c)+CORSIKA	~1 month	0
MDS1d	CELL+DIO(95MeV/c)+CORSIKA+RPC	1month	1e-13
MDS1e	CELL+DIO(95MeV/c)+CORSIKA+RPC+PU	1year	1e-13
MDS0f	CELL+DIO(95MeV/c)+CORSIKA+RPC+PU	1year	random
MDS0g	CE+DIO(95MeV/c)+CORSIKA+RP+PU	1year	0

process	tag	events
CeMLeadingLog	MDC2024a_sm4	800K
DIOtail (95MeV/c)	MDC2024a_sm4	very large
DIOtail_95 (95MeV/c)	MDC2020ai	1 year
DIOtail_75 (75MeV/c)	MDC2020ai	1 year
DIOtail (75MeV/c)	MDC2024a_sm3	1 week
CORSIKA	MDC2020ae
pile-up/stops	MDC2020p	-

Mock Dataset 2 (MDS2)

Here we add in the RPC/RMC streams and also provide positron samples ... TBC