Analysis

Particle Identification

Electron

Cuts

Calorimeter based cuts

The distributions below represent two types of cuts applied to improve the electron particle identification (PID) using a 4 GeV electron beam incident on an NH3 target. The electron calorimeter is segmented into an inner[math]EC_{inner}[/math] and an outer[math]EC_{outer}[/math] region. The total energy absorbed by the calorimeter system is recorded in the variable [math]EC_{tot}[/math]. The momentum ([math]P[/math]) is calculated using the reconstructed track and the known torus magnetic field. The distributions of [math]EC_{tot}[/math] and [math]EC_{inner}[/math] are shown below where both have been divided by the electron momentum and no cuts have been applied.

[math]EC_{tot}\gt 0.2*p[/math]

Without any cuts we have 181018 entries. After using the following cut [math]EC_{tot}\gt 0.2*p[/math] we are getting 127719 entries, which is about 70.55% of 181018.

[math]EC_{inner}\gt 0.08*p[/math]

After the cut on the energy deposited into inner part of electron calorimeter, number of entries decreases by 22%.

Both cuts are applied

In case of using the cuts of the total deposited energy and the energy deposited into inner calorimeter number of entries decreases ~36%

summary table

Beam Energy	Torus Current	Begin Run	End Run	cuts
1606	1500	25488	25559
1606	1946	25560	25605
1606	1500	25669	25732
1606	1500	25742	26221
1606	-1500	26222	26359
5764	-2250	26468	26722
5764	0	26723	26775
5764	-2250	26776	26851
5735	-2250	26874	27068
5735	2250	27069	27198
2288	1500	27205	27351
5627	2250	27356	27364
5627	-2250	27366	27380
5627	2250	27386	27499
5627	965	27502	27617
1724	-1500	27644	27798
2562	-1500	27799	27924
2792	-1500	27936	27941
2562	-1500	27942	27995
2562	1500	28001	28069
4239	2250	28074	28277
4239	-2250	28280	28479
4239	2250	28482	28494
4239	-2250	28500	28505
4239	2250	28506	28510
1724	1500	28512	28526
1724	-1500	28527	28532
3210	-2250	28549	28570