10 - H1 - Desy

124 Cross section building
MPI
f theor
1.1
MPI
f theor
1.1
MPI
f theor
1.1
1
1
1
0.9
0.9
0.9
0.8
0.8
0.8
0.7
0.6
6 8 10 12 14 γ
E T [GeV]
i
0.7
0.6
-1 0 1 2
ii
γ
η
0.7
iii
0.6
6 8 10 12 14 γ
E T [GeV]
MPI
f theor
1.1
MPI
f theor
1.1
MPI
f theor
1.1
1
1
1
0.9
0.9
0.9
0.8
0.8
0.8
0.7
iv
0.6
-1 0 1 2
γ
η
0.7
0.6
v
5 10 15
jet
E T [GeV]
0.7
0.6
vi
-1 0 1 2
jet
η
MPI
f theor
1.1
MPI
f theor
1.1
MPI
f theor
1.1
1
1
1
0.9
0.9
0.9
0.8
0.8
0.8
0.7
vii
0.6
0 0.5 1
LO x γ
0.7
0.6
viii
0.02 0.04 0.06
LO x p
0.7
ix
0.6
0 2 4 6 8
p
MPI
f theor
1.1
MPI
f theor
1.1
MPI
f theor
1.1
1
1
1
0.9
0.9
0.9
0.8
0.8
0.8
0.7
x
0.6
130 140 150 160 170 180
∆φ
0.7
xi
0.6
0 2 4 6 8
p
0.7
xii
0.6
130 140 150 160 170 180
∆φ
Figure 8.14: Multi parton interaction correction ftheor MPI , together with its uncertainty as
determined for all the final cross sections. The cross sections codes as defined in table 8.1
are given in relevant places.
presents the ftheor isol corrections for all the final cross sections. The correction is in general
positive and usually below 5%. It rises to values above 5% in the forward region, which
may be associated with the increase of the local particle density. The comparison of
corrections in the inclusive and exclusive phase spaces leads to the conclusion that the
additional selection of the hadronic jet does not affect the isolation of the photon. The
strongest correction of almost 10% can be seen in the lowest x LO
γ bin for the predominantly
resolved events. For the high x LO
γ values, where direct events accumulate, as well as for
the cross sections in the direct enhanced phase space, the correction is below 1%.
8.7.3 Hadronisation correction
The data measurement is presented as a cross section on a hadron level and parton level
calculations must be corrected for hadronisation effects. A hadronisation correction factor