Loading in 2 Seconds...
Loading in 2 Seconds...
Status of the PrimEx Experiment: A Precision Measurement of the Neutral Pion Lifetime. 7 th European Conference on “Electromagnetic Interactions with Nucleons and Nuclei” Milos Island, Greece September 12-15, 2007 Dan Dale Idaho State University. Participating Institutions.
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
7th European Conference on
“Electromagnetic Interactions with Nucleons and Nuclei”
Milos Island, Greece
September 12-15, 2007
Idaho State University
North Carolina A&T State University University of Massachusetts
University of Kentucky Idaho State University
Jefferson Lab Hampton University
MIT University of North Carolina at Wilmington
Catholic University of America Arizona State University
University of Virginia ITEP, Russia
IHEP, Russia Norfolk State University
University of Illinois Kharkov Inst. of Physics and Technology
Chinese Institute of Atomic EnergyIHEP, Chinese Academy of Sciences
George Washington University Yerevan Physics Institute, Armenia
Southern University at New Orleans Tomsk Polytechnical University, Russia
University of Sao Paulo
radiative width extraction
Leading order corrections (Donoghue, 1989)
po -> g g decay width (eV)
Next to Leading
Order, +- 1%
Expected PrimEx error bar,
arbitrarily projected to the
leading order chiral anomaly
G(pogg) = 7.93 eV
Known, measured quantities
enables separation of
new state of the art po detector
validate setup and analysis techniques.
Tagged photon beam
1152 PbWO4 and
576 lead glass modules
1.6% energy resolution
1-2 mm position resolution
of detector modules.
e+ - e - pair spectrometer
Monitored during production data taking.
Stable to 1%.
Independent of rate!
(1)Bethe-Heitler (modified by nuclear form factor).
(2)Virtual Compton scattering.
(5)Electron field pair production.
Total Probability = Timing x Mass x Elasticity
Nuclear coherent and
Primakoff – NC interference
HYCAL – Tagger timing
Carbon:G = 8.20 ±0.15 eV ± 0.20 eV Lead: G = 8.11 ± 0.16 eV± 0.20 eV
G = 7.98 ± 0.18eV
G = 7.94 ± 0.18eV
G = 7.95 ± 0.13eV
Carbon G = 8.41 eV± 0.15 eV ± 1.8%
Carbon: G = 8.20 eV ± 0.15 eV ± 0.20 eV
Lead: G = 8.11 eV± 0.16 eV ± 0.20 eV
Carbon: G = 7.98 eV± 0.18 eV
Lead: G = 7.94eV± 0.18 eV
Carbon and Lead: G = 7.95eV± 0.13 eV
(Phys. Lett., vol 158B, no. 1, 81, 1985)
po`s produced by 450 GeV protons in tungsten foils.
p o decays observed by detection of 150 GeV/c positrons
produced by decay g rays converting in foils.
Y(d) = N[A + B(1-e-d/l)]
Dalitz decay, g conversion in first foil