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Current work

070601

Resolution plotsTrying to implement basic cuts to select QE+VP from events that pass precuts:
See Friday slides for compact presentation.


Applied 2 cuts:
Chenrenkov angle of least energetic ring <38
Cos(Angle between 2 rings) < 0.5
Based on the plots presented on 070528.

The results are in this table

20 yrs of MC	Rec signal	Rec BG	Total
MC signal	98	53	151
MC BG	473	2753	3226
Total	571	2806	3377

And here are the effect on the resultion:
Energy
Angular


070531
Resolution plots:
Here is the method I used.
I looked at events which pass the set of precuts I and have a visible proton.


Momentum of the proton:
The momentum of the proton ring was reconstructed as:


pp=sqrt((sqrt(amomm(i)**2.+mmu**2.)+ coeffmu)**2
     &     -mp**2)


where coeffmu = 1262 MeV

This is basically correcting such that Ep=Emu+1262 which is what was done in Ishitsuka's thesis for pions.
(1262 =1422-160 =E threshold proton -E threshold-muon)

Note if the ring was elike I used amome, me, and coeffe=1460 (maybe not good idea, will check again)

Costheta:
Costheta was computed as usual, but plugging the momentum of the proton instead of the momentum of the pion (amomp)

Energy of incoming neutrino:

Using the momentum of the proton and the energy of the proton, I just computed an elastic collision  energy:
energy=(mmu**2+mp**2-mn**2-(2*costheta*pp*pmu)+2*emu*ep)/(2*mn)


And here are the plots:
Energy resolution (qe event +visible proton only)
Costheta resolution (qe event +visible proton only)

Energy resolution (FCFV,2 rings, most energetic ring is mulike)
Costheta resolution (FCFV, 2 rings, most energetci ring is mulike)


Is the 2nd ring really the proton:

	2nd ring is really the proton	2nd ring is not really the proton
4 years of MC total=26	19	7

when the 2nd ring is not the proton it is usually a pi+ from secondaries or a photon.





070530
A few little studies:
It is surprising that among FCFV QE mulike 2 rings, only about half of them have a visible proton.
The question is what is the 2nd ring when there is no visible proton.
I scanned 4 years (~1461 days) of MC and here is what I get:

Number of events	Fake 2nd ring	Muon hard-scattered	Secondaries	others/hard to tell
total=27	9	10	6	2

070528

Modifications since last time:
- Ask most energetic ring to be mulike (not 1st ring) (I checked, does not have much effects on event which pass the precuts)
- Use a new dash program
- Run on Neut MC and Nuance MC

Some results:
Here are a few numbers and a few plots:

Numbers normalized to 1489 days:

	neut	nuance
In FV:	15957	15063
In FV and QE:	7479	7434.
FV,QE,2 rings,     most energetic ring=mulike (precuts I):	63	51
Precuts I+ visible proton:	34	23
FV, 2rings    most energetic ring=mulike (precuts II):	666	585
Precuts II+ visible proton:	150	33

And here are some plots (not normalized, done with neut MC)

Assuming an event pass the precuts I (only QE events), here are a few distributions:
black = event has a visible proton
red  = event does not have a visible proton

    Cherenkov angle
    Angle between the 2 rings
    Number of decay electron

Assuming an event pass the precuts II (also nonQE events), here are a few distributions:
black = event has a visible proton
red  = event does not have a visible proton

    Cherenkov angle
    Angle between the 2 rings
    Number of decay electron



070405

Energy spectrum of the outgoing proton for:

and here is the plot

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Talks


May 31th, 2007
    Comments on improving the L/E resolution
    in the case of QE events with a visible proton (2 ring sample)
    April 11th, 2007
    About reconstructing the proton for QE events.