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CLAS Approved Analysis (CAA) of E1-6 experiment

Spokesperson
M. Osipenko
Year
2002
Abstract
Semi-inclusive π+ electroproduction on protons has been measured with the CLAS detector at Jefferson Lab. The measurement was performed on a liquid-hydrogen target using a 5.75 GeV electron beam. The complete five-fold differential cross sections were measured over a wide kinematic range including the complete range of azimuthal angles between hadronic and leptonic planes, φ, enabling us to separate the φ-dependent terms. Our measurements of the φ-independent term of the cross section at low Bjorken x were found to be in fairly good agreement with pQCD calculations. Indeed, the conventional current fragmentation calculation can account for almost all of the observed cross section, even at small π+ momentum. The measured center-of-momentum spectra are in qualitative agreement with highenergy data, which suggests a surprising numerical similarity between the spectator diquark fragmentation in the present reaction and the antiquark fragmentation measured in e+e- collisions. We have observed that the two φ-dependent terms of the cross section are small. Within our precision the cos2φ term is compatible with zero, except for the low-z region, and the measured cosφ term is much smaller in magnitude than the sum of the Cahn and Berger effects.
Publication
  1. M. Osipenko, M. Ripani, G. Ricco, and CLAS Collaboration Measurement of semi-inclusive π+ electroproduction off the proton. // Phys.Rev.D80,032004 (2009)
Quantities
d5σ/dx dQ2 dz dp2T dφ

Measurements

ID Quantity Beam Target Final state Q2min,
GeV2 		Q2max,
GeV2 		Wmin,
GeV 		Wmax,
GeV
E29M1 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.30999994 1.55999994 2.77873182 3.32660913
E29M2 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.30999994 1.55999994 2.54370999 3.0044775
E29M3 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 2.74540997 3.26278234
E29M4 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 2.53031421 2.97659636
E29M5 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 2.34733605 2.73858333
E29M6 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 2.18866634 2.53574014
E29M7 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 2.04891992 2.35949779
E29M8 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 1.92424142 2.20394278
E29M9 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 1.81178606 2.06483841
E29M10 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 1.70939994 1.93905461
E29M11 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 1.6154151 1.82421768
E29M12 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 1.52851522 1.71848536
E29M13 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 1.4476434 1.62039936
E29M14 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 1.37193704 1.52878308
E29M15 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.55999994 1.87 1.30068183 1.44267082
E29M16 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 2.73858333 3.22433543
E29M17 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 2.53574014 2.96212411
E29M18 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 2.35949779 2.73831248
E29M19 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 2.20394278 2.5435245
E29M20 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 2.06483841 2.37128496
E29M21 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 1.93905461 2.21695065
E29M22 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 1.82421768 2.07708716
E29M23 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 1.71848536 1.94908464
E29M24 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 1.62039936 1.83091283
E29M25 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 1.52878308 1.72095788
E29M26 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 1.44267082 1.6179111
E29M27 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 1.36125588 1.52068985
E29M28 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 1.28385282 1.42837989
E29M29 d5σ/dx dQ2 dz dp2T dφ e p π++X 1.87 2.23000002 1.20986795 1.34019196
E29M30 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 2.73831248 3.20878601
E29M31 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 2.5435245 2.9621737
E29M32 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 2.37128496 2.74722576
E29M33 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 2.21695065 2.5568521
E29M34 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 2.07708716 2.38596463
E29M35 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 1.94908464 2.23079371
E29M36 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 1.83091283 2.08846998
E29M37 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 1.72095788 1.95675349
E29M38 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 1.6179111 1.83385706
E29M39 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 1.52068985 1.71832156
E29M40 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 1.42837989 1.6089288
E29M41 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 1.34019196 1.50463629
E29M42 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.23000002 2.66000009 1.25542772 1.40452719
E29M43 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 2.5568521 2.9707725
E29M44 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 2.38596463 2.76082087
E29M45 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 2.23079371 2.57206535
E29M46 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 2.08846998 2.40037107
E29M47 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 1.95675349 2.24258447
E29M48 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 1.83385706 2.09623575
E29M49 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 1.71832156 1.95934546
E29M50 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 1.6089288 1.83028555
E29M51 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 1.50463629 1.70768356
E29M52 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 1.40452719 1.59034693
E29M53 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 1.30776775 1.47720397
E29M54 d5σ/dx dQ2 dz dp2T dφ e p π++X 2.66000009 3.17000008 1.21356976 1.36725044
E29M55 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 2.57206535 2.99010253
E29M56 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 2.40037107 2.78158665
E29M57 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 2.24258447 2.59162283
E29M58 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 2.09623575 2.41673923
E29M59 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 1.95934546 2.2542088
E29M60 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 1.83028555 2.10183358
E29M61 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 1.70768356 1.95779407
E29M62 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 1.59034693 1.82053792
E29M63 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 1.47720397 1.68869531
E29M64 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 1.36725044 1.56100559
E29M65 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.17000008 3.78999996 1.25949681 1.43624878
E29M66 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 2.41673923 2.80011153
E29M67 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 2.2542088 2.6069212
E29M68 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 2.10183358 2.42706418
E29M69 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 1.95779407 2.25810575
E29M70 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 1.82053792 2.09801459
E29M71 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 1.68869531 1.94503939
E29M72 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 1.56100559 1.79760849
E29M73 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 1.43624878 1.65424228
E29M74 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 1.31316817 1.51346171
E29M75 d5σ/dx dQ2 dz dp2T dφ e p π++X 3.78999996 4.51999998 1.19036925 1.37367642
E29M76 d5σ/dx dQ2 dz dp2T dφ e p π++X 4.51999998 5.4000001 2.09801459 2.43318319
E29M77 d5σ/dx dQ2 dz dp2T dφ e p π++X 4.51999998 5.4000001 1.94503939 2.25548911
E29M78 d5σ/dx dQ2 dz dp2T dφ e p π++X 4.51999998 5.4000001 1.79760849 2.08526516
E29M79 d5σ/dx dQ2 dz dp2T dφ e p π++X 4.51999998 5.4000001 1.65424228 1.92070866
E29M80 d5σ/dx dQ2 dz dp2T dφ e p π++X 4.51999998 5.4000001 1.51346171 1.76008391
E29M81 d5σ/dx dQ2 dz dp2T dφ e p π++X 4.51999998 5.4000001 1.37367642 1.60159981
E29M82 d5σ/dx dQ2 dz dp2T dφ e p π++X 4.51999998 5.4000001 1.23302066 1.44324946
E29M83 d5σ/dx dQ2 dz dp2T dφ e p π++X 5.4000001 6.44999981 1.92070866 2.24112916
E29M84 d5σ/dx dQ2 dz dp2T dφ e p π++X 5.4000001 6.44999981 1.76008391 2.05797768
E29M85 d5σ/dx dQ2 dz dp2T dφ e p π++X 5.4000001 6.44999981 1.60159981 1.8785857
E29M86 d5σ/dx dQ2 dz dp2T dφ e p π++X 5.4000001 6.44999981 1.44324946 1.70079875
E29M87 d5σ/dx dQ2 dz dp2T dφ e p π++X 5.4000001 6.44999981 1.282552 1.5221076
E29M88 d5σ/dx dQ2 dz dp2T dφ e p π++X 6.44999981 7.69999981 1.33925724 1.61096108
E29M89 d5σ/dx dQ2 dz dp2T dφ e p π++X 6.44999981 7.69999981 1.14743936 1.40377986
Created in SINP MSU, CLAS Collaboration