CLAS Physics Database

Measurement E179M27

Experiment: SIDIS Dihadron Beam Spin Asymmetry
Year: 2020

Measurement comment:

Binning scheme: bins of z, for Mh below and above 0.63 GeV

Experiment comment:


Process: ep→eπ+π-X
Data tables have the following columns:
  1. mean Q2
  2. mean x
  3. mean Mh, the dihadron invariant mass
  4. mean z, of the pion pair
  5. mean PT, more commonly written Ph, is the component of the total dihadron momentum, transverse to q
  6. ALU amplitude, for a particular modulation
  7. statistical uncertainty
  8. systematic uncertainty
For each of the 7 asymmetry modulations, there are 4 tables, one for each binning scheme: (1) binned by x, (2) binned by Mh, (3) binned by z and Mh, and (4) binned by PT and Mh.
Spokespersons: C. Dilks, T. Hayward, A. Vossen
Reaction: ep → π π + X
Polarization: beam (longitudinal)
Quantity: ALUsin (3φh−2φR)
Q2: 1.0 — 10.6 GeV2
W: 2.0 — 4.0 GeV
x: 0.06 — 0.77
Ebeam: 10.6041 GeV
Publication:
T.B. Hayward, C. Dilks, A. Vossen, H. Avakian Observation of Beam Spin Asymmetries in the Process ep→eπ+π-X with CLAS12 // (submitted to PRL)

Measurement data
Q2, [GeV2] x M(π+), [GeV] z PT, [GeV] ALUsin (3φh−2φR) uncertainty
3.129 0.22 0.464 0.4 0.598 -0.00283495 0.00624507
3.21 0.244 0.468 0.474 0.61 -0.00765638 0.00650735
3.131 0.248 0.472 0.528 0.608 0.00227299 0.00612132
3.107 0.254 0.47 0.579 0.59 0.00247075 0.00658439
3.021 0.253 0.478 0.638 0.556 -0.00403083 0.00606138
2.825 0.234 0.482 0.727 0.5 -0.012363 0.00689485
2.764 0.192 0.821 0.404 0.386 0.00122143 0.00547485
2.847 0.209 0.859 0.474 0.427 -0.00862729 0.0052856
2.862 0.218 0.88 0.528 0.451 0.00635544 0.00437321
2.85 0.223 0.9 0.58 0.466 0.00184596 0.00516362
2.785 0.221 0.921 0.638 0.467 0.0159268 0.00470316
2.628 0.202 0.958 0.731 0.438 0.0121319 0.00467986