Analysis

EG1 run database
run summary
polarization info

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 [math] EC_{tot}\gt 0.2*p [/math] and [math] EC_{inner}\gt 0.08*p [/math]

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

The "# of triggers" columns represents the number of events which generated a signal above threshold in the calorimeter and the scintillator. The expected # of events column represents the number of reconstructed events with tracks that also make it through the cuts defined in the table.

The semi-inclusive analysis will focus on the 4 GeV and 6 GeV data which have both inbending and outbending torus settings. Specifically runs 28074 - 28579 ( 4 GeV) and Runs 27356 - 27499 and 26874 - 27198 (6 GeV)

Beam Energy	Torus Current	Begin Run	End Run	file used	cuts			# trig([math]10^6[/math])	expected # evts([math]10^6[/math])	p<3,[math]EC_{tot}\gt 0.2*p [/math],[math] EC_{inner}\gt 0.08*p[/math](%)	p>3,[math]EC_{tot}\gt 0.24*p [/math],[math] EC_{inner}\gt 0.06*p[/math](%)
					[math]EC_{tot}\gt 0.2*p[/math]	[math]EC_{inner}\gt 0.08*p[/math]	[math]EC_{tot}\gt 0.2*p [/math] and [math] EC_{inner}\gt 0.08*p[/math]
1606	1500	25488	25559	dst25504_02.B00	64%	49.5%	78%	60	3.2
1606	1946	25560	25605			44
1606	1500	25669	25732	dst25669_02.B00	64%	49%	78%	226	10
1606	1500	25742	26221	dst25754_02.B00	21%	11%	24%	3154	13.3
1606	-1500	26222	26359	dst26224_02.B00	4.6%	3%	6.6%	703	13.1
1724	-1500	27644	27798	dst27649_02.B00	4.8%	2.2%	5.9%	211	20
1724	1500	28512	28526			159
1724	-1500	28527	28532			93
2288	1500	27205	27351	dst27225_02.B00	20.2%	13%	25.6%	1647	16.1
2562	-1500	27799	27924	dst27809_02.B00	5.7%	4.6%	8.6%	1441	13.1
2562	-1500	27942	27995	dst27942_02.B00	6.1%	4.4%	8.9%	841	32.3
2562	1500	28001	28069	dst28002_02.B00	27.8%	13%	29.6%	1013	30.7
2792	-1500	27936	27941	dst27937_02.B00	6.7%	5%	9.9%	69	20.6
3210	-2250	28549	28570			436
4239	2250	28074	28277	dst28075_02.B00	35.3%	23.9%	40.5%	2278	19.6
4239	-2250	28280	28479	dst28281_02.B00	9.1%	9.4%	13.6%	2620	15.2
4239	2250	28482	28494			7
4239	-2250	28500	28505			107
4239	2250	28506	28510	dst28509_02.B00	29.5%	22%	36%	75	18.1
5627	2250	27356	27364	dst27358_02.B00	33.2%	27.8%	41.3%	56	19.4	44.6	40.1
5627	-2250	27366	27380	dst27368_02.B00	12.6%	14.8%	19.5%	130	13.6	25.3	8.8
5627	2250	27386	27499	dst27388_02.B00	33.4%	27.8%	41.4%	1210	20.2	44.8	40.1
5627	965	27502	27617			493
5735	-2250	26874	27068	dst26904_02.B00	13%	15%	20%	1709	19.9	25.6	9.1
5735	2250	27069	27198	dst27070_02.B00	33.3%	28.8%	42.2%	1509	15	46	40.2
5764	-2250	26468	26722	dst26489_02.B00	12.2%	14.4%	19.1%	1189	10	24.6	9.3
5764	0	26723	26775			268
5764	-2250	26776	26851	dst26779_02.B00	13.5%	15.5%	20.5%	662	15.9	26.4	9.2

Cut on the number of photoelectrons

In this case is used a cut on the number of photoelectrons, which is [math]nphe\gt 2.5[/math]. The plots below show the effect of the number of photoelectrons cuts on the Cerenkov distribution. We see that after using cut the number of entries decreases ~40.7%

Used cuts [math]EC_{tot}\gt 0.24p[/math] and [math]EC_{inner}\gt 0.06p[/math]

Used file dst28181_03(energy 4.2GeV). In this case was applied cuts on the polar angle([math]15\lt \theta\lt 20[/math]) and momentum([math]2.2\lt P\lt 2.6[/math]). Number of entries decreased by 96%(?????????????/)

Tamuna: follow this link to see the OSIPENKO cuts described in part 5 add graphs of their effect below
Dr. Forest I think I did this cuts but they do not change a lot. Maybe I am wrong.

Plot of [math]EC_{tot}/p[/math] vs [math]EC_{inner}/p[/math]

In this case is used file dst27070(Energy 5.735 GeV and Torus 2250) and are applied the following EC cuts: For ECtotal - [math]EC_{tot}\gt 0.2p[/math], for EC inner - [math]EC_{inner}\gt 0.08p[/math].

P<3

After using above cuts the number of entries decreases ~46%

0.5<P<1

The number of entries decreased by ~51.8%

1<P<1.5

The number of entries decreased approximately by 47.8%

1.5<P<2

In this case the number of entries decreased by 46.1%

2<P<2.5

In this case the number of entries decreased by 38%

P>3

Used file dst27070(Energy 5.735 GeV and Torus 2250) and are applied the following EC cuts: For ECtotal - [math]EC_{tot}\gt 0.24p[/math], for EC inner - [math]EC_{inner}\gt 0.06p[/math].

The number of entries decreased by~40.2%

Plot of EC_tot/P vs nphe for Electrons

Used file dst27070(Energy 5.735 GeV and Torus 2250)

p<3 GeV

Does the graph below only contain electrons?  I assume so just restate it here for clarity.  At the bottom of this 
section you have plots for pions and electrons side by side.  Move those to the pion section below.  Does this 
mean there are a lot of pions mis-identified as electrons?

Dr. Forest, the graph bellow does not contain only electrons, there should be some contamination, because I have just 
 p<3 GeV cut.

p<3 GeV and [math]EC_{inner}\gt 0.08p[/math]

p<3 GeV, [math]EC_{inner}\gt 0.08p[/math] and [math]EC_{tot}\gt 0.2p[/math]

p<3 GeV, [math]EC_{inner}\gt 0.08p[/math], [math]EC_{tot}\gt 0.2p[/math] and nphe>2.5

 Dr. Forest , in this case I applied all cuts as you see. 

The histogram below is for electrons.

Pion

Summary Table

Tamuna:  
The pion id code is at:

http://www.jlab.org/Hall-B/secure/eg1/EG2000/josh/pion.cc

There are two subroutines, one which uses a constant cut for every paddle, 
one that has a different cut for every paddle.  The only other requirement 
is that the particle be produced with an angle less than 48 degrees in the 
 lab (so as to miss the magnet can).  The requirment that the pion fail the 
electron cut is not written in stone.  I still haven't checked to see the 
effects of it.

Beam Energy	Torus Current	Begin Run	End Run	file used	cuts			# trig([math]10^6[/math])	expected # evts([math]10^6[/math])	p>3,[math]EC_{tot}\lt 0.2*p [/math],[math] EC_{inner}\lt 0.08*p[/math](%)	p<3,[math]EC_{tot}\lt 0.24*p [/math],[math] EC_{inner}\lt 0.06*p[/math](%)
					[math]EC_{tot}\gt 0.2*p[/math]	[math]EC_{inner}\gt 0.08*p[/math]	[math]EC_{tot}\gt 0.2*p [/math] and [math] EC_{inner}\gt 0.08*p[/math]
1606	1500	25488	25559	dst25504_02.B00				60	3.2
1606	1500	25669	25732	dst25669_02.B00				226	10
1606	1500	25742	26221	dst25754_02.B00				3154	13.3
1606	-1500	26222	26359	dst26224_02.B00				703	13.1
1724	-1500	27644	27798	dst27649_02.B00				211	20
2288	1500	27205	27351	dst27225_02.B00				1647	16.1
2562	-1500	27799	27924	dst27809_02.B00				1441	13.1
2562	-1500	27942	27995	dst27942_02.B00				841	32.3
2562	1500	28001	28069	dst28002_02.B00				1013	30.7
2792	-1500	27936	27941	dst27937_02.B00			%	69	20.6
4239	2250	28074	28277	dst28075_02.B00	%	%	%	2278	19.6
4239	-2250	28280	28479	dst28281_02.B00	%	%	%	2620	15.2
4239	2250	28506	28510	dst28509_02.B00	%	%	%	75	18.1
5627	2250	27356	27364	dst27358_02.B00	%	%	%	56	19.4	36.1	31.5
5627	-2250	27366	27380	dst27368_02.B00	%	%	%	130		25	43.8
5627	2250	27386	27499	dst27388_02.B00	%	%	%	1210	20.2	39.8	32.4
5735	-2250	26874	27068	dst26904_02.B00	%	%	%	1709	19.9	22.5	46.4
5735	2250	27069	27198	dst27070_02.B00	%	%	%	1509	15	34.6	32.9
5764	-2250	26468	26722	dst26489_02.B00	%	%	%	1189	10	25.2	44.3
5764	-2250	26776	26851	dst26779_02.B00	%	%	%	662	15.9	21.3	44

Plot of EC_tot/P vs nphe for Pions