BeamSpotMon threshold updates for 2025 (!586) · Merge requests · LHCb / MooreOnline

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Description

BeamSpotMon threshold updates for 2025.

Threshods for publication

The threshold for change in the transverse mean PV position is reduced to 10 micron from 50 micron. In addition, 10 micron thresholds are added for transverse changes of the beamspot major axes at z=-600 mm and at z=600 mm. Configured as

    beam_spot_moni = BeamSpotMonitor(
              :
        MaxAbsDeltaMap={
            'rho': 0.01 * mm,
            'rho_at_z1': 0.01 * mm,
            'rho_at_z2': 0.01 * mm,
        },
        Z1ForRhoAtZ1Thresh=-600 * mm,
        Z2ForRhoAtZ2Thresh=600 * mm,
              :
        )

Sample size for valid condition

The sample size required to produce a valid set of conditions is increased from 2500 PVs to 50000 PVs (see 'Beamspot monitor' on 03 Apr 2025 RTA WP4/5). Configured as

    beam_spot_moni = BeamSpotMonitor(
              :
        MinPVsForCalib=500000,  # Based on std dev of x and y and thresholds
              :
        )

PV position filter

The set of PVs used as input to the to the BeamSpotMonitor algorithm are given additional cuts to prevent inclusion of material interactions. The cuts are |x_{\text{PV}}| < 2.5mm and |y_{\text{PV}}| < 2.5mm, configured as

        VertexListRefiner(
              :
            MinX=-2.5 * mm,  # Set to exclude material interactions
            MaxX=2.5 * mm,
            MinY=-2.5 * mm,
            MaxY=2.5 * mm,
              :
            ).OutputLocation
    }

Event Selection

The event selection for the monitor input is changed from Hlt1 Routing Bit 1 (Lumi events) to Hlt1 Routing Bit 14 (Physics events). Configured as

        rb_filter = HltRoutingBitsFilter(
            RawBanks=default_raw_banks('HltRoutingBits'),
            RequireMask=(1 << 14, 0, 0),  # Phys events
            PassOnError=False)

BeamSpotMon threshold updates for 2025