CLAS Physics Database

Measurement E179M21

Experiment: SIDIS Dihadron Beam Spin Asymmetry
Year: 2020

Measurement comment:

Binning scheme: bins of x

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 (−φh+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 (−φh+2φR) uncertainty syst. uncert.
1.542 0.105 0.83 0.531 0.55 -0.0238802 0.00434757 0.00133410662445207
1.783 0.127 0.809 0.547 0.53 -0.0125572 0.00444284 0.000705805217562235
1.953 0.143 0.794 0.557 0.526 -0.0135531 0.00449827 0.000734826710481693
2.105 0.157 0.78 0.559 0.52 -0.0105369 0.00445668 0.00167049223325057
2.286 0.174 0.763 0.566 0.506 -0.0259787 0.00412498 0.00162909644704201
2.471 0.191 0.749 0.571 0.5 -0.0178146 0.00440338 0.000779171105179299
2.707 0.211 0.743 0.571 0.492 -0.0167748 0.00401048 0.000747193918836166
3.003 0.235 0.733 0.572 0.485 -0.015275 0.00418429 0.00071470628554275
3.307 0.261 0.716 0.571 0.468 -0.0123639 0.00446662 0.00072491693090043
3.721 0.294 0.701 0.569 0.46 -0.0155508 0.00422874 0.000807232378449816
4.337 0.342 0.679 0.565 0.44 -0.0162239 0.00434631 0.00133339145861348
5.658 0.44 0.63 0.547 0.408 -0.00682949 0.00448022 0.000666074917491984