KTeV Kl3 radiative decays plots
Updated November 10, 2004.
[Kl3 radiative decays Results]
"Measurements of the Branching Fraction and Decay Distributions
for K_{L}> pi^{+}mu^{+}nu gamma and
K_{L}> pi^{+}e^{+}nu gamma"

feyn_diag.eps,
feyn_diag.pdf
FIG. 1: Feynman diagrams for the firstorder radiative corrections to the K_{l3} decay mode. Diagrams (a)(f) are the virtual corrections while diagrams (g)(i) are the innerbremsstrahlung corrections. The open circles in diagram (b) and (c) denote the selfenergy correction to the pion and lepton wavefunctions, respectively.


detector_noreg.eps,
detector_noreg.pdf
FIG. 2: Plan view of the KTeV(E832) detector. The evacuated decay volume ends with a thin vacuum window at Z=159m. K_{L} decays from the two neutral beams are the source of semileptonic decays.


csilayout.eps,
csilayout.pdf
FIG. 3: Layout of CsI calorimeter. The small crystals (inner region have dimension 2.5 x 2.5 x 50 cm^{3}. The two neutral beams go through the beam holes (into pagee) shown by the two inner squares. The fiducial cut, indicated by the dark lines, excludes radiated photons that hit a crystal near the beam holes or near the outer boundary.


pp0kin_bkg.eps,
pp0kin_bkg.pdf
FIG.4: k_{+0} distribution for (a) K_{mu3gamma}, and (b) K_{e3gamma}. Arrows indicate selected events for the K_{l3gamma} samples. Each peak at k_{+0} ~ 0 is background from K_{L}>pi^{+}pi^{}pi^{0} decays.


csiadc.eps,
csiadc.pdf
FIG. 5: For radiated photon cluster candidates in the K_{e3gamma} sample, (a) cluster energy deposit in RF bucket prior to event, and (b) cluster energy deposit in the first RF bucket. Energy is shown as ADC counts (1 ADC count i about 1 MeV). The arrow in each plot indicates the selected region.


xbrem.eps,
xbrem.pdf
FIG. 6: (a) Top view of spectrometer (DC14) and CsI calorimeter, and overlay of K_{e3gamma} decay. Delta R_{gammabrem} is the distance between the photon candidate at the CsI and the location of the electron track projected from upstream of the magnet (dotted line); the latter is where a photon from external bremsstrahlung woudl hit the CsI. (b) Delta R_{gammabrem} distribution for data (dots), for MC with radiated photons (dashed histogram). Plots are shown after K_{e3gamma} requirements. The arrow indicates the analysis selection.


bkgkm3cm.eps,
bkgkm3cm.pdf
FIG. 7: For K_{L}>pi^{+}mu^{+}nu gamma candidates without background subtraction, (a) minimum E^{*}_{gamma} and (b) maximum cos(theta^{*}_{gamma e}) for the tow kinematic solutions. Dots are data, and dashed histogram is the background predicted by the MC.


bkgke3cm.eps,
bkgke3cm.pdf
FIG. 8: For K_{L}>pi^{+}e^{+}nu gamma candidates without background subtraction, (a) minimum E^{*}_{gamma} and (b) maximum cos(theta^{*}_{gamma e}) for the tow kinematic solutions. Dots are data, and dashed histogram is the background predicted by the MC.


brkm3rad_compare.eps,
brkm3rad_compare.pdf
FIG. 9: Comparisons of R_{Kmu3gamma} among experiment and theory for (a) E^{*}_{gamma} > 10 MeV, and (b) E^{*}_{gamma} > 30 MeV. The experimental results are from KTeV and NA48. The thoery predictions are from Andre and from Fearing, Fischbach, and Smith, FFS. The FFS prediction is determined by NA48, and is corrected by (1 + delta^{mu}_{K})^{1}. The theory uncertainties are taken to be delta^{mu}_{K} = 0.019 times the prediction.


brke3rad_compare.eps,
brke3rad_compare.pdf
FIG. 10: Comparison of R_{Ke3gamma} among experiment and theory for (a)E^{*}_{gamma} > 10 MeV, and (b) E^{*}_{gamma} > 30 MeV and theta^{*}_{gamma e} > 20^{o}. The experimental results are from KTeV (this result and also KTeV 01), and NA31. The theory predictions are from Andre, Fearing, Fischbach, and Smith, FFS, Bijnens, and PHOTOTS. The FFS prediction is dtermined by Doncel and by KTeV, and each is corrected by (1 + delta^{e}_{K})^{1}. The theory uncertainties are taken to be delta^{e}_{K} = 0.013 times the prediction. The PHOTOS predictions fro one and two radiative photosn are described in Sec. VI B.


km3cm.eps,
km3cm.pdf
FIG. 11: DataMC comparison of K_{mu3gamma} kinematics. For the two kaon energy solutions in the lab, (a) minimum radiated photon energy in kaon rest frame, and (b) maximum cosine of the photonmuon angle in kaon rest frame. Data are shown in dots; MC in histogram. The chi^{2}/dof at the top of each plot refers to the dataMC comparison; data/MC ratios are shown in the lower plots. All K_{mu3gamma} selection requirements have been applied, and background is subtracted.


ke3cm.eps,
ke3cm.pdf
FIG. 12: DataMC comparison of K_{mu3gamma} kinematics. For the two kaon energy solutions in the lab, (a) minimum radiated photon energy in kaon rest frame, and (b) maximum cosine of the photonmuon angle in kaon rest frame. Data are shown in dots; MC in histogram. The chi^{2}/dof at the top of each plot refers to the dataMC comparison; data/MC ratios are shown in the lower plots. All K_{e3gamma} selection requirements have been applied.


kmu4.eps,
kmu4.pdf
FIG. 13: For the two kaon energy solutions, the invariant muonneutrino mass closest to pion mass (m'_{mu nu}) is shown in (a) for data (dots) and MC K_{L}> pi^{+}pi^{}pi^{0} (histogram). (b) shows the m'_{mu nu} distribution for MC K_{L}>pi^{0}pi^{+}mu^{+}nu. The vertical lines show the selection window for K_{L}>pi^{0}pi^{+}mu^{+}nu candidates. All K_{L}>pi^{0}pi^{+}mu^{+}nu selection requirements, except for m'_{mu nu}, have been applied.


k2pimip.eps,
k2pimip.pdf
FIG. 14: For reconstructed K_{L,S}>pi^{+}pi^{} decays with an extra cluster that satisfies the K_{l3gamma} photon identification requiremetns, (a)pigamma separation at CsI (with separataion cut removed) and (b) photon eneryg distribution. Samples shown are data (dots), MC (histogram), and MC without pihadron interactions (sashedhistogram). The MC is normalized to the total numbers of K_{L,S}>pi^{+}pi^{} candidates.

Send corrections to Taku Yamanaka