Z mass resolution release 17 Data/MC based on the MC with realistic Rt, A lines and errors

Z mass resolution release 17Z mass resolution release 17Data/MCData/MC

based on the MC with based on the MC with realistic Rt, A lines and errorsrealistic Rt, A lines and errors

Niels van Eldik, Peter Kluit, Alan Poppleton

Muon week 16 November discussed at MATF 2 November

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Z mass ID-IDZ mass ID-IDBased on the v35 processing

compared to release 17 Rt + A + Error

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Z mass CB-CBZ mass CB-CBData MC rel 17 comparisonData MC rel 17 comparison

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Reasonable agreement additional smearing needed

Z mass CB-CB MuidZ mass CB-CB MuidRt A lines and errorsRt A lines and errors

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Z mass SA-SAZ mass SA-SAData MC rel 17 comparisonData MC rel 17 comparison

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Not so good agreement….

Z mass SA-SA MuidZ mass SA-SA MuidRt A lines and errorsRt A lines and errors

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MS-ID momentumMS-ID momentumData MC comparison: BarrelData MC comparison: Barrel

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Barrel Large η 1.1 and Small sectors η 1.0Excellent agreement Data/MC

MS-ID momentumMS-ID momentumTransition regionTransition region

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Transition Large η 1.4 and Small η 1.7 sectorsNot so good agreement with MC: Transition region is worse in data

MS-ID momentum EndcapMS-ID momentum Endcap

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Endcap rest η range < 2.0 Large and SmallReasonable agreement: small sectors a bit worse than Large

MS-ID momentum CSCMS-ID momentum CSC

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Endcap rest η range < 2.0 Large and SmallReasonable agreement: small sectors slightly worse

Need More statistics

MS-ID momentum pull MS-ID momentum pull BarrelBarrel

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Pull distribution agrees very well Data/MC

MS momentum error MS momentum error BarrelBarrel

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Momentum error distribution for SA track: pretty similar

MS-ID momentum pull MS-ID momentum pull TransitionTransition

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Not so good agreement in this region (see also dp/p in T region)

MS momentum error MS momentum error TransitionTransition

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Error distribution SA track is similar Data/MC

MS-ID momentum pull MS-ID momentum pull EndcapEndcap

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Some small differences e.g. Small Chambers

MS momentum error MS momentum error Endcap Endcap

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Tendency that error in MC is smaller

MS-ID momentum pull MS-ID momentum pull CSCCSC

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Reasonable agreement except for Small

MS momentum error CSCMS momentum error CSC

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Error distribution SA track is different for Data/MC(this is known: due to CSC hit errors. In data there are less unspoiled clusters)

MS-ID momentumMS-ID momentum< 3 station tracks< 3 station tracks

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ConclusionsConclusions

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Significant improvement in Data/MC agreement using the simulation including realistic Rt smearing, A lines and errors.

Performed further checks• Mass ID/CB/SA• Comparing dp/p = (pSA – pID) / pID and dp/error• Expected momentum error

• Barrel looks in excellent shape • Transition region: MC is too optimistic in dp/p (p error OK)• Endcap region: 5-10% discrepancy in dp/p; p error a bit too optimistic• CSC region: some discrepancy dp/p. Probably due to the fact that the CSC hit errors are not correctly simulated (in data there are more spoiled clusters)• < 3 station tracks need more smearing Efficiency cross check: MC with/without RtAE lines differ < 0.1%