KTeV pi0>4e plots
Updated May 8, 2008.
[pi0> 4e Results]

ddfeyngstar.eps,
ddfeyngstar.pdf
FIG.1: Lowest order Feynman diagram for pi^{0}>e^{+}e^{}e^{+}e^{}. The direct contribution is shown; a second diagram exists with e_{1}^{+} and e_{2}^{+} exchanged.


meeeesplit.eps,
meeeesplit.pdf
FIG.2: Invariant e^{+}e^{}e^{+}e^{} mass for data events identified by teh preferred pairing as KL_{L}>pi^{0}pi^{0}pi^{0}_{DD} (upper panel) and K_{L}>pi^{0}pi^{0}_{D}pi^{0}_{D} (lower panel).


x1x20214.eps,
x1x20214.pdf
FIG.3: Distribution of the kinematic variables x_{1} and x_{2} for signal event candidates (points) and signal Monte Carlo simulation with best fit form factor parameters (histogram).


phi0214.eps,
phi0214.pdf
FIG.4: Distribution of the angle phi, in units of pi, between the planes of the two e^{+}e^{} pairs. The solid histogram shows the Monte Carlo expectation for negative parity.

Plots shown at
DPF2002
by Pat Toale (May 2002)

dpf.ps
Transparencies


trksep.eps
The distribution of the distance between two tracks at the first drift chamber are shown for various Monte Carlo events. DD: pi0>4e, 2D: 2 Dalitz decays, 1C: 1 Dalitz + 1 photon had an external conversion, and 2C: no Dalitz + 2 photons had external conversions.


mass.eps
4e+4gamma mass distributions for the 1997(top) and 1999(bottom) data. The left plots show the pi0>4e candidates, and the right plots show the 2 Dalitz decay candidates.


ff0.eps
MC distribution of x at generation. Distribution of x for a=0 (cross) and a=0.032 (hist). Bottom plot shows the ratio between them.


ff11.eps
Distribution of x for data and treelevel MC (a=0). The bottom plot shows the data/MC ratio.


ff3.eps
Distribution of x for treelevel MC (a=0) and MC with O(alpha^3) radiative corrections. The bottom plot shows the ratio between them. Note that the ratio is similar to f11.eps, which indicates that the data has a similar shape as MC with O(alpha^3) radiative corrections.


rc5.eps
The distribution of phi (angle between two ee planes) for MC with radiative corrections (cross) and treelevel MC (histogram). The bottom plot shows the ratio between them. The horizontal axis is in units of radian/pi. Note that radiative corrections pull the distribution toward the center (1).


rc7.eps
The distribution of phi for data (cross) and treelevel MC (histogram). The bottom plot shows the ratio betwen them. Note that the distribution for data is also pulled toward the center, as for MC with radiative corrections.


rc7.eps
The distribution of phi for data (cross) and treelevel MC (histogram). The bottom plot shows the ratio betwen them. Note that the distribution for data is also pulled toward the center, as for MC with radiative corrections.

Send corrections to Taku Yamanaka