CERN Accelerating science

Measured energy distributions for data and simulation (normalized to the number of events in data) for nominal positron beam energies ranging from 20 to 300~\GeV. In this figure, a scale factor of 1.035 has been applied to the data.

Measured energy distributions for data and simulation (normalized to the number of events in data) for nominal positron beam energies ranging from 20 to 300~\GeV. In this figure, a scale factor of 1.035 has been applied to the data.

Measured energy distributions for data and simulation (normalized to the number of events in data) for nominal positron beam energies ranging from 20 to 300~\GeV. In this figure, a scale factor of 1.035 has been applied to the data.

Measured energy distributions for data and simulation (normalized to the number of events in data) for nominal positron beam energies ranging from 20 to 300~\GeV. In this figure, a scale factor of 1.035 has been applied to the data.

Measured energy distributions for data and simulation (normalized to the number of events in data) for nominal positron beam energies ranging from 20 to 300~\GeV. In this figure, a scale factor of 1.035 has been applied to the data.

Measured energy distributions for data and simulation (normalized to the number of events in data) for nominal positron beam energies ranging from 20 to 300~\GeV. In this figure, a scale factor of 1.035 has been applied to the data.

Measured energy distributions for data and simulation (normalized to the number of events in data) for nominal positron beam energies ranging from 20 to 300~\GeV. In this figure, a scale factor of 1.035 has been applied to the data.

Measured energy distributions for data and simulation (normalized to the number of events in data) for nominal positron beam energies ranging from 20 to 300~\GeV. In this figure, a scale factor of 1.035 has been applied to the data.

: Mean measured energy as a function of the beam energy for data and simulation after applying a scale factor of 1.035 to the data. The ratio of the data to the MC mean measured energy is displayed in the lower panel (error bars are evaluated by propagating the errors on the mean measured energies). \ \newline

: Linearity with the energy. The measured energies $E$ are divided by the slope $m$ obtained from a linear fit to $<\!E\!>$ as a function of $E_{beam}$, with the slope and intercept allowed to float. The yellow band represents the relative error on the beam energy from the uncertainty of the dipole currents corresponding to an uncertainty of $\pm 1$ \GeV in momentum.

Relative energy resolution for measured energy in data and simulation.

Distribution of residuals of the reconstructed $x$ shower position measured in layer 7 with respect to the predicted one from the DWC track extrapolation for 300~GeV positrons. The residual distribution from the simulation, shown in red, includes the resolution of the DWCs.

Combined CE-E prototype and DWC position resolution in $x$ in the single layer located at a depth of 6.7$~X_{0}$ as a function of the incident positron energy for data and simulations with (CE-E and DWC) and without (CE-E intrinsic) DWC resolution included in the DWC simulated measurements.

: Combined shower axis and DWC position resolution at the $COG_z$ for data and simulations with (CE-E and DWC) and without (CE-E intrinsic) DWC resolution.

: Shower axis angular resolution for data and simulations with (CE-E and DWC) and without (CE-E instrinsic) DWC resolution. \newline