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| </table> | | </table> |
| + | ==Three-pion acceptance is considered== |
| + | [[File:First try study eta acceptance.pdf|first try of taking three-pion decay modes into consideration]] |
| | | |
| ==Reference== | | ==Reference== |
| arxiv:1209.2469 | | arxiv:1209.2469 |
Revision as of 17:07, 8 September 2014
Idea
B(inivisible)/B(normalization)={N(upper limit)/efficiency(invisible)}/{N(normalization)/efficiency(normalization)} * {1/(1-sigma)}
- B(inivisible): branching ratio of the invisible decay
- B(normalization): branching ratio of the reference channel
- N(upper limit): upper limit of the yield of the invisible decay
- N(normalization): yield of the reference channel
- efficiency(invisible): acceptance of the invisible decay
- efficiency(normalization): acceptance of the reference channel
- sigma: systematic uncertainty
What applies here:
The channel we are using is : gamma p -> p eta_prime -> p pi+ pi- (eta). The invisible decay of eta is eta -> xx. x is something like U boson, which could be dark photon or heavy photon.
B(normalization) is 1 when we obtain eta by requiring the missing mass.
efficiency(invisible)=efficiency(normalization) * efficiency (invisible decay of eta). efficiency(normalization) is the detection efficiency of p pi+ pi-. efficiency(invisible) is the product of efficiency(normalizaiton) and efficiency(invisible decay of eta). efficiency(invisible decay) is the detection efficiency of at least one photon from eta decay.
photon detection efficeincy
procedure
- collection events of p, pi+, pi- and one or two photons
- requiring the missing mass of p pi+ pi- to be pi0
- requiring the missing mass of p to be eta or omega
- events passing the above three conditions are called "all" events
- two-photon events are called "good" events
-
- the ratio of "good" events to "all" events is the detection efficiency of photon
- the ratio is binned in energy, theta, and phi angle in lab frame
result
Error creating thumbnail: File missing efficiency of photon in cosine theta vs. phi |
Error creating thumbnail: File missing efficency of photon in momentum vs. phi after selection cosine theta between 0.7 and 0.98 |
Eta acceptance
File:Eta efficiency.pdf
partial statistics
The following is from 2% of the data.
Different efficiency
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Compare expected and no-photon detected
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance with acceptance larger than 0.5 |
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance for all events |
Error creating thumbnail: File missing Ratio of the events of no photon detected to all events (red) and expected events to all events (blue) |
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance for all events with PART bank |
Error creating thumbnail: File missing Ratio of the events of no photon detected to all events (red) and expected events to all events (blue) with PART bank |
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance larger than 50% with PART bank |
Error creating thumbnail: File missing Ratio of the events of no photon detected (red) and expected events (blue) to acceptance larger than 50% with PART bank |
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance for all events with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Ratio of the events of no photon detected to all events (red) and expected events to all events (blue) with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance larger than 50% with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Ratio of the events of no photon detected (red) and expected events (blue) to acceptance larger than 50% with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Study of the difference
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance for all events with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Ratio of the events of no photon detected to all events (red) and expected events to all events (blue) with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance larger than 50% with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Ratio of the events of no photon detected (red) and expected events (blue) to acceptance larger than 50% with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance larger than 60% with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Ratio of the events of no photon detected (red) and expected events (blue) to acceptance larger than 60% with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Compare the events of no photon detected with expected from acceptance larger than 70% with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Error creating thumbnail: File missing Ratio of the events of no photon detected (red) and expected events (blue) to acceptance larger than 70% with PART bank and validating photon with missing mass squre between [-0.1,0.1] |
Three-pion acceptance is considered
File:First try study eta acceptance.pdf
Reference
arxiv:1209.2469