l1 trigger rate study

1

L1 Trigger Rate Study

Nathaniel Amos

2

Part 1

• GMT Eta Distributions

3

GMT Eta Distribution

• Studied Eta distribution of GMT output• Can be used to estimate GMT Rate in Eta• Data sample taken from: – Runs: 190389-194115– HLT_L1SingleMuOpen and json_DSConly.txt

• GMT Qualities selected:– Quality 5: RPC Only– Quality 6: DT or CSC, No RPC– Quality 7: DT/RPC or CSC/RPC

4

GMT Eta Distribution

Eta

Spikes

5

What causes the spikes?

• Observe each subsystem independently– Observe GMT-DT matches at GMT Quality 6, 7– Observe GMT-CSC matches at GMT Quality 6, 7• If GMT Eta > 2.1, require CSCTF Mode 5

– Observe RPC-GMT matches at GMT Quality 5 and GMT BX = 0

• Plot each Eta distribution

6

GMT-CSC Matches at Quality = 6

Eta

No spike observed at |Eta| = 1.0

7

GMT-CSC Matches at Quality = 7

Eta

No spike observed at |Eta| = 1.0

8

GMT-CSC Matches at 5 ≤ Quality ≤ 7

Eta

No spike observed at |Eta| = 1.0

9

GMT-RPC Matches at Quality = 5

Eta

10

GMT-DT Matches at Quality = 6

Eta

Spikes

11

GMT-DT Matches at Quality = 7

Eta

12

GMT-DT Matches at 5 ≤ Quality ≤ 7

Eta

Spikes

13

Part 2

• GMT Relative Rates

14

Relative GMT Matches

• Plot number of GMT-subsystem matches relative to total number of GMT matches– Plotted for each category (below)

• Define several categories for matches:– DT, |Eta| < 0.9– CSC, 1.2 < |Eta| < 2.1

• or 1.2 < |Eta| < 2.0 (See next slides)– RPC, |Eta| < 1.6– DT Overlap, 0.9 < |Eta| < 1.2– CSC Overlap, 0.9 < |Eta| < 1.2

15

Two Methods of Plotting• Plot GMT-subsystem matches divided by total

number of GMT matches (referred to as “relative counts”)

• Plot GMT-subsystem matches divided by total number of GMT matches per subsystem region width (a type of rate density)– Example:

• CSC (1.2 < |Eta| < 2.1): each Eta bin has width of Eta = 0.1• Therefore CSC relative counts divided by 18 bins

16

Relative Counts, |Eta| < 2.1

60% of the GMT matches come from the CSCs.

17

Relative Counts Per Region Width,|Eta| < 2.1

The spikes we saw in the Overlap region from the DT each come in a single bin (Eta = ±1.0)

The DT overlap region produces a much greater contribution per bin.

18

Relative Counts, |Eta| < 2.0

Now, with |Eta| strictly less than 2.0, the CSCs are seen to contribute less than 30% of the GMT tracks (outside the overlap region).

A lot of rate is bottled up in that extra Eta bin at ±2.1 (some tracks maybe have ME1/1 A station).

19

Relative Counts Per Region Width, |Eta| < 2.0

Once again, with the width of the full region reduced from |Eta| < 2.1 to |Eta|< 2.0, the CSCs are seen to contribute much less rate.

The DT Overlap’s spikes are very apparent here.

20

Conclusions

• Spikes do not appear to come from CSC– But there is a lot of rate at 2.0 <|Eta| < 2.1

• Some tracks may come from ME 1/1A

• DT in overlap region shows spikes– Appears to be Eta = ±1.0

• Plan to repeat study– Use HLT_L1SingleMu10

• More statistics– JSON_MuonPhys.txt

• Exclude possible problems in muon system