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The final inclusive and semi-inclusive longitudinal double-spin asymmetries at HERMES [Elektronische Ressource] : extraction of quark helicity distributions of the nucleon from deep-inelastic scattering / vorgelegt von Polina Kravchenko

186 pages
The final inclusive and semi-inclusive longitudinaldouble-spin asymmetries at HERMES. Extraction of quarkhelicity distributions of the nucleon from deep-inelasticscattering.Der Naturwissenschaftlichen Fakult¨atder Friedrich-Alexander-Universit¨at Erlangen-N¨urnbergzurErlangung des Doktorgradesvorgelegt vonPolina Kravchenkoaus Sankt Petersburg, RusslandiAls Dissertation genehmigt von der Naturwissen-schaftlichen Fakult¨at der Universit¨at Erlangen-Nu¨rnbergTag der mu¨ndlichen Pru¨fung: Oktober 7, 2010Vorsitzender der Promotionskommision: Prof. Dr. Rainer FinkErstberichterstatter: Prof. Dr. Klaus RithZweitberichterstatter: Prof. Dr. Michael ThiesContentsList of Tables viList of Figures viii1 Introduction 12 Spin Structure of the Nucleon 42.1 Deep Inelastic Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42.1.1 Kinematics of the Deep-Inelastic Scattering . . . . . . . . . . . . . . . . . . . . 42.1.2 The Deep-Inelastic Scattering Cross section . . . . . . . . . . . . . . . . . . . . 82.1.3 The photon-nucleon asymmetries . . . . . . . . . . . . . . . . . . . . . . . . . . 162.2 The parton model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182.2.1 The simple parton model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182.2.2 The spin crisis in the parton model . . . . . . . . . . . . . . . . . . . . . . . . . 202.3 Semi-Inclusive Deep Inelastic Scattering . . . . . . . . . . .
Voir plus Voir moins

The final inclusive and semi-inclusive longitudinal
double-spin asymmetries at HERMES. Extraction of quark
helicity distributions of the nucleon from deep-inelastic
scattering.
Der Naturwissenschaftlichen Fakult¨at
der Friedrich-Alexander-Universit¨at Erlangen-N¨urnberg
zur
Erlangung des Doktorgrades
vorgelegt von
Polina Kravchenko
aus Sankt Petersburg, Russland
iAls Dissertation genehmigt von der Naturwissen-
schaftlichen Fakult¨at der Universit¨at Erlangen-Nu¨rnberg
Tag der mu¨ndlichen Pru¨fung: Oktober 7, 2010
Vorsitzender der Promotionskommision: Prof. Dr. Rainer Fink
Erstberichterstatter: Prof. Dr. Klaus Rith
Zweitberichterstatter: Prof. Dr. Michael ThiesContents
List of Tables vi
List of Figures viii
1 Introduction 1
2 Spin Structure of the Nucleon 4
2.1 Deep Inelastic Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1.1 Kinematics of the Deep-Inelastic Scattering . . . . . . . . . . . . . . . . . . . . 4
2.1.2 The Deep-Inelastic Scattering Cross section . . . . . . . . . . . . . . . . . . . . 8
2.1.3 The photon-nucleon asymmetries . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.2 The parton model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.1 The simple parton model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.2.2 The spin crisis in the parton model . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.3 Semi-Inclusive Deep Inelastic Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . 23
3 The HERMES experiment 25
3.1 The polarized lepton beam of the HERA storage ring. . . . . . . . . . . . . . . . . . . 25
3.2 The internal gas target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.3 The HERMES spectrometer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.3.1 Magnet and tracking detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.2 Particle IDentification detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.4 Data Structure and Data Acquisition System . . . . . . . . . . . . . . . . . . . . . . . 36
3.4.1 Data structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
3.4.2 Data Acquisition and Production . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4 Data Selection and Particle Identification 39
4.1 Burst-level data selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
4.2 Particle identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2.1 Discriminating leptons and hadrons . . . . . . . . . . . . . . . . . . . . . . . . 41
4.2.2 Identification of hadrons with the RICH . . . . . . . . . . . . . . . . . . . . . . 43
4.3 Event selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
4.3.1 Inclusive requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
4.3.2 Geometric requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
iii4.3.3 Semi-inclusive requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
4.4 Binning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
5 Double spin asymmetries 52
5.1 Determination of the double-spin asymmetries . . . . . . . . . . . . . . . . . . . . . . . 52
5.1.1 Correction of yields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.2 Extraction of Born asymmetries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
5.2.1 Smearing correction and QED radiative correction . . . . . . . . . . . . . . . . 56
5.2.2 Acceptance correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
5.3 Systematic uncertainties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.3.1 Polarization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.3.2 RICH unfolding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.3.3 Azimuthal correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.4 Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
5.4.1 A (x) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 711
5.4.2 3D asymmetries A (x,z,p ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 721 ⊥h
5.4.3 A (x,p ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 721 ⊥h
25.4.4 2D asymmetries A (x,Q ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791
5.4.5 Hadron charge difference asymmetries . . . . . . . . . . . . . . . . . . . . . . . 84
5.4.6 Comparison of result to COMPASS experiment . . . . . . . . . . . . . . . . . . 91
6 Quark Helicity Distributions 92
6.1 Formalism of Helicity-Distribution Extraction . . . . . . . . . . . . . . . . . . . . . . . 92
6.2 Extraction of the Purities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
6.3 Systematic studies on the purity uncertainties. . . . . . . . . . . . . . . . . . . . . . . 99
6.3.1 The influence of the spectrometer acceptance on the purities . . . . . . . . . . 100
6.3.2 NLO effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
6.3.3 Dependence of purities on fragmentation functions . . . . . . . . . . . . . . . . 100
6.4 Systematic studies on the quark polarizations . . . . . . . . . . . . . . . . . . . . . . . 103
6.5 Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109
6.5.1 The quark polarizations Δq/q : 3D extraction . . . . . . . . . . . . . . . . . . . 109
6.5.2 The quark polarizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
6.5.3 The polarized parton densities . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
6.5.4 Comparison with theoretical prediction . . . . . . . . . . . . . . . . . . . . . . 115
6.5.5 Final result for quark helicity distributions . . . . . . . . . . . . . . . . . . . . 115
6.6 The Hadron-Charge-Difference-Asymmetry Method . . . . . . . . . . . . . . . . . . . . 118
6.6.1 The hadron-charge-difference asymmetry. Formalism. . . . . . . . . . . . . . . 118
6.6.2 Determination of moments of the distributions . . . . . . . . . . . . . . . . . . 122
7 Conclusions 126
8 Zusammenfassung 128A Results: Asymmetries A (x) 1301
B Results: Asymmetries A (x,p ) 1371 h⊥
C Results: Asymmetries A (x,z,p ) 1411 h⊥
2D Results: Asymmetries A (x,Q ) 1541
E Hadron charge difference asymmetry 160
Bibliography 162List of Tables
1.1 Overview of investigations of the nucleon structure . . . . . . . . . . . . . . . . . . . . 3
2.1 Alegend ofkinematicquantitiesusedinthedescriptionofdeep-inelasticcharged-lepton
nucleon scattering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
ˇ3.1 Refractive indices and Cerenkov light thresholds of the RICH . . . . . . . . . . . . . . 32
4.1 Burst-level data quality requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
ˇ4.2 Beam, target and Cerenkov detector type for each year of HERMES running. . . . . . 43
4.3 Inclusive kinematic requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.4 Geometric requirements for inclusive and semi-inclusive events. . . . . . . . . . . . . . 48
4.5 Semi-inclusive requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.6 Count numbers of DIS leptons and SIDIS hadrons for the hydrogen and deuterium data. 50
5.1 Kinematics of final state radiation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
5.2 Fractional uncertainties of beam and target and their quadratic sum by year . . . . . 70
25.3 The value of χ for each functional form fit to the A (x,p ) data points for each1 h⊥
target–final-state-hadron combination. . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
6.1 First moments of various helicity distributions in the measured range at a scale of
2 2Q =2.5 GeV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
A.1 1-Dimensional x binning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
A.2 Inclusive Born level asymmetries on the proton target . . . . . . . . . . . . . . . . . . 131
A.3 Inclusive Born level asymmetries on the deuteron target . . . . . . . . . . . . . . . . . 131
A.4 Born level asymmetries for hadrons on the proton target . . . . . . . . . . . . . . . . . 132
A.5 Born level asymmetries for pions on the proton target . . . . . . . . . . . . . . . . . . 133
A.6 Born level asymmetries for hadrons on the deuteron target. . . . . . . . . . . . . . . . 134
A.7 Born level asymmetries for pions on the deuteron target . . . . . . . . . . . . . . . . . 135
A.8 Born level asymmetries for kaons on the deuteron target . . . . . . . . . . . . . . . . . 136
B.1 2-Dimensional x−p binning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137h⊥
B.2 Semi-Inclusive Born level asymmetries for positive and negative pions on the proton
target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
viB.3 Semi-Inclusive Born level asymmetries for positive and negative pions on the deuteron
target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
B.4 Semi-Inclusive Born level asymmetries for positive and negative kaons on the deuteron
target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
C.1 The bin edges for z and p added to form a 3D binning. . . . . . . . . . . . . . . . . 141h⊥
C.2 Born level asymmetry for positive pions on the proton target . . . . . . . . . . . . . . 142
C.3 Born level asymmetries for negative pions on the proton target . . . . . . . . . . . . . 144
C.4 Born level asymmetries for positive pions on the deuteron target . . . . . . . . . . . . 146
C.5 Born level asymmetries for negative pions on the deuteron target . . . . . . . . . . . . 148
C.6 Born level asymmetries for positive kaons on the deuteron target . . . . . . . . . . . . 150
C.7 Born level asymmetries for negative kaons on the deuteron target . . . . . . . . . . . . 152
2D.1 2-Dimensional x−Q binning. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
D.2 Semi-Inclusive Born level asymmetries for positive and negative hadrons on the proton
target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155
D.3 Semi-Inclusive Born level asymmetries for positive and negative pions on the proton
target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
D.4 Semi-InclusiveBornlevelasymmetriesforpositiveandnegativehadronsonthedeuteron
target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
D.5 Semi-Inclusive Born level asymmetries for positive and negative pions on the deuteron
target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
D.6 Semi-Inclusive Born level asymmetries for positive and negative kaons on the deuteron
target . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
E.1 Pions charge difference asymmetry on the proton target . . . . . . . . . . . . . . . . . 160
E.2 Hadrons charge difference asymmetry on the deutron target . . . . . . . . . . . . . . . 161
E.3 Pions charge difference asymmetry on the deutron target . . . . . . . . . . . . . . . . 161
E.4 Kaons charge difference asymmetry on the deutron target . . . . . . . . . . . . . . . . 161List of Figures
2.1 Sketch of the deep-inelastic scattering process in the one-photon approximation as seen
in the laboratory system. The definitions of the kinematic variables are summarized in
Tab. 2.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 As the energy of the virtual photon increases, increasingly small sub-structures (par-
tons) can be resolved. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
p
2.3 An overview of the proton structure function F [33] measured in lepton-proton scat-2
tering with positrons by HERMES, the collider experiments (H1 and ZEUS) in the
kinematic domain of HERA for x > 0.00006, and for electrons (SLAC, JLAB[31]) and
pmuons (BCMS, NMC and E665). The world data of F is compared to phenomenolog-2
p2ical parameterizations. The Q dependence of F is shown in bins of x. The values of2
p
F were scaled by powers of 1.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
d2.4 The world data of F is compared to the SMC phenomenological parameterization[32].2
2 d dTheQ dependenceofF is shownin binsofx. Thevalues ofF were scaled bypowers2 2
of 1.6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.5 The ratio of longitudinal and transverse cross sections R =σ /σ as a function of x inL T
2three ranges of Q . The solid line shows the parameterization R1998[34]. Also shown
are measurements from various experiments. The dashed lines show the results of a
next-to-next-to-leading order calculation in perturbative QCD. . . . . . . . . . . . . . 13
′~ ~2.6 The definition of angles. Here k and k are momentum vectors of the incoming and
scattered lepton respectively. Angles θ and φ represent the polar angle with respect
~to k and azimuthal angle which is defined by an angle between scattering plane and
polarization plane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.7 The spin-dependent structure function xg (x) of the proton and deuteron shown on1
separate panels measured as a function of x in deep inelastic scattering of polarized
electrons/positrons. The HERMES result [14] is compared to the data from SMC
[36][,37][,38], E143[39], E155[40][,41], and COMPASS[16]. The error bars represent the sum
in quadrature of statistical and systematic uncertainties. For the HERMES data the
2 2closed (open) symbols represent values derived by selecting events with Q > 1 GeV
2 2(Q < 1 GeV ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
viiipn d2.8 Top panel : xg from data for g and g , compared with similar data from SMC1 1 1
n[36],[37],[38], E143[39], E155[40],[41] in the HERMES x-range. Middle panel: xg as1
3obtained from a He target by JLab[20], HERMES[42], E142[43] and E154[44]. Bottom
2panel: averageQ versusx. For theHERMESdatatheclosed (open)symbolsrepresent
2 2 2 2values derived by selecting events with Q > 1 GeV (Q < 1 GeV ). . . . . . . . . 16
2.9 Schematic diagram of the polarizad DIS in Quark Parton Model. The arrows indicate
the spins of the virtual photon, the partons and the nucleon. . . . . . . . . . . . . . . 17
2.10 Visualization of parton density q(ξ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.11 Lepton-quark elastic scattering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
2.12 Visualization of the longitudinally polarized parton density Δq(x). The upper arrows
show the spin direction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1 Sketch of the HERA facility at DESY . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.2 Example for a measurement of the polarization build-up of the HERA positron beam
as measured by both the Transverse and the Longitudinal Polarimeter. . . . . . . . . . 27
3.3 Diagram of the target chamber. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.4 Schematic view of the HERMES spectrometer. . . . . . . . . . . . . . . . . . . . . . . 29
3.5 Front scheme of HERMES spectrometer: the angular acceptance is limited in the az-
imuthal angle φ by the blue dotted lines, and in the polar angle θ by the red dotted
circles. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.6 A perspective view of the upper RICH detector setup. . . . . . . . . . . . . . . . . . . 32
3.7 Distribution ofreconstructedangles intheHERMESRICH.Theuppertripletofcurves
corresponds to aerogel events, and the lower to gas events. From left to right the
contours in each case are for π, K and p.. . . . . . . . . . . . . . . . . . . . . . . . . . 33
3.8 Side view of the TOP half of the TRD: when an electron track and a pion track pass
through the six modules of the TRD, only the electron is emitting transition radiation
photons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
3.9 Responses of three PID detectors: Number of counts for positrons (empty histograms)
and hadrons (shaded histograms) in TRD, hodoscope H2 and the calorimeter. . . . . . 35
3.10 Overview of the preshower and the calorimeter. . . . . . . . . . . . . . . . . . . . . . . 36
4.1 A 3-dimensional view of the positron-hadron separation dueto all the four PID detectors. 42
4.2 The p-matrix represents the conditional probability that a hadron of true type h willt
be identified by the RICH as type h . The momenta p are given in GeV. . . . . . . . 44i h
24.3 The distribution of the selected DIS events in the x−Q plane. . . . . . . . . . . . . . 47
5.1 DIS process in first order QED (Born level). The scattering kinematics are well defined
by the properties of the incident and scattered electron. . . . . . . . . . . . . . . . . . 55
5.2 Second order QED radiative corrections for the DIS process. . . . . . . . . . . . . . . . 57
5.3 Diagram of final state radiation. The diagram illustrates the emission of an undetected
photon with energy ω before the detection of the scattered lepton. . . . . . . . . . . . 585.4 Migration matrices for a pure x binning. The matrices were extracted from a fully
reconstructed Monte Carlo data set simulating bothQED radiative and detector effects
for inclusive (left panel) DIS and semi-inclusive production of positive pions (right
panel) on a proton target. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
5.5 Monte Carlo asymmetries for the proton in HERMES acceptance (red triangles) and
in 4π (green diamonds). The black points represent the differences in the asymmetries
acc 4πΔA =A −A whichcanbeattributedentirelytothedifferenceinaverage kinematics. 621 1 1
5.6 Monte Carlo asymmetries for the deuteron in HERMES acceptance (red triangles) and
in 4π (green diamonds). The black points represent the differences in the asymmetries
acc 4πΔA =A −A whichcanbeattributedentirelytothedifferenceinaverage kinematics. 631 1 1
5.7 Definition of azimuthal angle of the hadron φ (here named φ ) for semi-inclusive deeph
inelastic scattering in the target rest frame. P is the transverse part of P withh⊥ h
respect to the photon momentum. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64
5.8 Comparisonof4πBornMonteCarlosampleswithandwithoutcos(φ)weighting. Asym-
metries for charged pions from the proton target and both pions and kaons from the
deuteron target are shown. Since there is no φ-dependent acceptance included, the
cosine moments of the unpolarized cross section integrate out over the full φ range. . . 68
5.9 Comparison of Born Monte Carlo samples with and without cos(φ) weighting in accep-
tance. Unlike the 4π comparison shown in Fig. 5.8, the nonuniform acceptance of the
spectrometer in φ creates significant differences between the weighted and unweighted
hasymmetries. The azimuthal correction factor C , which is simply the ratio of the two
φ
asymmetries, is also shown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.10 The inclusive and semi-inclusive Born level asymmetries on the proton, corrected for
instrumental smearing and QED radiative effects. The error bars give the statistical
uncertainties, and the colored bands indicate the systematic uncertainty. . . . . . . . . 73
5.11 The inclusive and semi-inclusive Born level asymmetries on the deuteron, corrected for
instrumental smearing and QED radiative effects. The error bars give the statistical
uncertainties,andthecoloredbandsindicatethesystematicuncertainty. Blacktriangles
and the lowermost bands are taken from the COMPASS publication[85]. . . . . . . . . 74
5.12 Thecharged hadronsBornlevel asymmetries for bothtargets , corrected for instrumen-
talsmearingandQEDradiativeeffects. Theerrorbarsgivethestatistical uncertainties,
and the colored bands indicate the systematic uncertainty. . . . . . . . . . . . . . . . . 75
5.13 The inclusive and semi-inclusive Born level asymmetries on the proton in comparison
with previous published HERMES result. . . . . . . . . . . . . . . . . . . . . . . . . . 76
5.14 The charged hadrons Born level asymmetries for both targets in comparison with pre-
vious published HERMES result. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
5.15 The inclusive and semi-inclusive Born level asymmetries on the deuteron in comparison
with previous published HERMES result. . . . . . . . . . . . . . . . . . . . . . . . . . 78
5.16 A (x,p )forchargedpionproductionforprotonanddeuterontargetsandchargekaon1 h⊥
production for deuteron target, in three different x ranges. . . . . . . . . . . . . . . . . 80

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