Deborah Harris Kevin McFarland

12 May 2016

0.E+00

1.E+20

2.E+20

3.E+20

4.E+20

5.E+20

6.E+20

7.E+20

8.E+20

9.E+20

1.E+21

Sep-13

Oct-13

Oct-13

Nov-13

Dec-13

Jan-14

Feb-14

Mar-14

Apr-14

May-14

Jun-14

Jul-1

4Au

g-14

Sep-14

Oct-14

Nov-14

Dec-14

Jan-15

Feb-15

Mar-15

Apr-15

May-15

Jun-15

Jul-1

5Au

g-15

Sep-15

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Jul-1

6Au

g-16

Proton

son

Target(PO

T)

DayintheMediumEnergyRun

POTDelivered

MINERvAPOT

MINERvA*MINOSPOT

MINERvA’s Run Plan •  In the LE beam:

–  3.5E20POT in neutrino mode

–  1.7E20POT in antineutrino mode

•  In the ME beam: 9.4E20POT accumulated so far in ν mode –  5E20 with full He target data –  4.4E20 with empty He target data –  Want another 0.6E20 empty target data, expect to get that by

summer shutdown •  We want 12E20 in antineutrino mode to complete our

medium energy physics program •  For 14 days of RHC run, 1.2E18/day: 1.7E19 POT

would be “lost” out of the remaining 6E19 POT 12 May 2016 DAH and KSM, MINERvA @ EMG 2

Water Target Exposure •  Water Target:

–  Filled target on Monday Feb. 22

–  Measured for creep every day the first week, now only measured once/week

–  Target is stable –  Have integrated

1.22E20POT –  Could get to

1.8E20POT –  2 weeks less would

mean 1.65E20 POT 12 May 2016 DAH and KSM, MINERvA @ EMG 3

He Target Exposure

•  Started ME run with full He target

•  Emptied He target in January 2014

•  Integrated 5.0E20 with target full

•  Integrated 4.4E20 with target empty so far

•  0.17 of the next 0.6E20POT won’t change background subtraction precision

•  Will start 2017 run with He target full again

12 May 2016 DAH and KSM, MINERvA @ EMG 4

Comparison of on-axis fluxes

12 May 2016 DAH and KSM, MINERvA @ EMG 5

Similar shapes, but antineutrino flux is peaked at 80% of neutrino flux Antineutrino Event rate per POT is therefore 0.4*Neutrino event rate

Expected Event Rates in RHC •  Rates in Scintillator in FHC: (for events with muons

tracked into MINOS)

12 May 2016 DAH and KSM, MINERvA @ EMG 6

•  Assume in RHC, with 0.17E20POT we would get factor of .075 times as many events than what is in this

•  plot for a 2 weeks run: 5k per GeV, 20k in total

•  Flux sample (“Standard Candle”): 2k per GeV, 8k total

Standard Candle Flux Events •  Low nu analysis: see Jeff Nelson’s

JETP talk on January 8, 2016 •  As hadron energy (“ν”) approaches 0,

σ(Ε) approaches a constant

•  Total energy distribution of “0 hadron energy” events provide shape of flux distribution

•  Normalize to external total cross section at higher energy

•  “Low-nu technique” •  Fraction of events that are •  “low-nu” is small, but analysis

keeps it at about 40% 12 May 2016 DAH and KSM, MINERvA @ EMG 7

Summary

•  For a switch to antineutrinos for 2 weeks before the shutdown: –  MINERvA would lose:

•  10% of the statistics we would collect on the H2O Target •  3% of the statistics we would collect on the empty He target •  1.7% of the statistics we would collect on the rest of MINERvA

–  MINERvA would gain: •  2k “standard candle” flux events/GeV in the peak of the neutrino

energy distribution •  8k flux events over all energies •  20k Charged Current Inclusive antineutrino events

•  Benefits outweigh the losses, assuming 1.2E18 POT/day

12 May 2016 DAH and KSM, MINERvA @ EMG 8

Event Rate Comparison FHC/RHC

•  Comparing quasi-elastic event rates in RHC and FHC:

12 May 2016 DAH and KSM, MINERvA @ EMG 9

For same mass, get half as many events/POT at QE peak