CLAS Physics Database

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Measurement E179M21

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Experiment: SIDIS Dihadron Beam Spin Asymmetry, 2020

Spokespersons: C. Dilks, T. Hayward, A. Vossen

Experiment comment:
Process: ep→eπ⁺π^-X
Data tables have the following columns:

mean Q²
mean x
mean M_h, the dihadron invariant mass
mean z, of the pion pair
mean P_T, more commonly written P_h^⊥, is the component of the total dihadron momentum, transverse to q
A_LU amplitude, for a particular modulation
statistical uncertainty
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 M_h, (3) binned by z and M_h, and (4) binned by P_T and M_h.

Measurement comment: Binning scheme: bins of x

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)

Quantity measured: A_LU^{sin (−φ_h+2φ_R}),
Beam spin asymmetry sin(−φ_h+2φ_R) moment
Beam: e, polarization: longitudinal
Target: p (Z=1, A=1), polarization: none
Final state: π π + X, polarization: none

Q² :	1 — 10.6 GeV²
W :	2 — 4 GeV
x_b :	0.06 — 0.77
E_beam :	10.6041 GeV

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Click here to get data in text file, delimited with tabs.

Measured data:

Q², GeV²	x	M(π⁺,π⁻), GeV	z	P_T, GeV	A_LU^{sin (−φ_h+2φ_R})	Data errors	Systematic errors
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