References - Bogoliubov Laboratory of Theoretical Physics - JINR

cos 0φ
LU,I
A
sin φ
ALU,I
sin 2φ
LU,I
A
Res. frac
0.4
0.2
0
0
−0.2
−0.4
−0.6
0
−0.2
−0.4
0.4
0.3
0.2
0.1
0
overall
4
2
0
0
.2
.4
.6
0
.2
.4
4
HERMES PRELIMINARY 3.4 % scale uncertainty
e±
+ p → e±
+ p + γ Accep & smear → sys error
0 0.2 0.4 0.6
4
3
2
.1
0
0 0.2 0.4 0.6
2
−t[GeV ]
2
0
0
.2
.4
.6
0
.2
.4
4
3
2
.1
0
0.1 0.2 0.3
0.1 0.2 0.3
xB
4
2
0
0
.2
.4
.6
0
.2
.4
4
3
2
.1
0
VGG Regge, D
VGG Fact., D
2 4 6 8 10
2 4 6 8 10
2 2
Q [GeV ]
Figure 3: The amplitudes of the beam-helicity asymmetry from the interference term on the unpolarized
hydrogen target [4]. The error bars (bands) represent the statistical (systematic) uncertainties. The
curves are predictions of a double-distribution GPD model [5, 6].
)
coh.
(-t < -t
φ
cos
C
A
)
incoh.
(-t > -t
φ
cos
C
A
0.1
0
0.1
0
Coherent enriched
(accep. & smearing → sys. error,
coherent fraction ~ 65%)
2
2
2
〈 -t〉
= 0.018 GeV , 〈 x 〉 = 0.065, 〈 Q 〉 = 1.70 GeV
B
HERMES PRELIMINARY
0 20 40 60 80 100 120 140
Incoherent enriched
(accep. & smearing → sys. error,
A
elastic incoherent fraction ~ 60%)
2
2
2
〈 -t〉
= 0.20 GeV , 〈 x 〉 = 0.11, 〈 Q 〉 = 2.85 GeV
B
0 20 40 60 80 100 120 140
A
)
coh.
(-t-t
(I),sinφ
LU
A
0
-0.5
0
-0.5
Coherent enriched
(accep. & smearing → sys. error,
coherent fraction ~ 65%,
4
except He~ 30% )
2
2
2
〈 -t〉
= 0.018 GeV , 〈 x 〉 = 0.065, 〈 Q 〉 = 1.70 GeV
B
1 Incoherent enriched 10
(accep. & smearing → sys. error,
elastic incoherent fraction ~ 60%)
2
2
2
〈 -t〉
= 0.20 GeV , 〈 x 〉 = 0.11, 〈 Q 〉 = 2.85 GeV
B
1 10
(a) (b)
HERMES PRELIMINARY
Figure 4: Nuclear-mass dependence of the cos φ amplitude of the beam-charge asymmetry (a) and of
the sin φ amplitude of the beam-helicity asymmetry (b) for the coherent-enriched (upper panels) and
incoherent-enriched (lower panels) data samples. The inner (full) errors bar represent the statistical
(total) uncertainties.
183
2
10
A
2
10
A