-
J R Batley,
G E Kalmus,
C Lazzeroni,
D J Munday,
M Patel,
M W Slater,
S A Wotton,
R Arcidiacono,
G Bocquet,
A Ceccucci, [......],
M Clemencic,
S Goy Lopez,
E Menichetti,
N Pastrone,
W Wislicki,
H Dibon,
M Jeitler,
M Markytan,
G Neuhofer,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: From the 2002 data taking with a neutral kaon beam extracted from the CERN-SPS, the NA48/1 experiment observed 97 Ξ0 → Σ+ μ- over(ν, -)μ candidates with a background contamination of 30.8 ± 4.2 events. From this sample, the BR (Ξ0 → Σ+ μ- over(ν, -)μ) is measured to be (2.17 ± 0.32stat ± 0.17syst) × 10- 6. © 2013 Elsevier B.V. All rights reserved.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 01/2013;
-
A. A. Alves Jr,
L. Anderlini,
M. Anelli,
R. Antunes Nobrega,
G. Auriemma,
W. Baldini,
G. Bencivenni,
R. Berutti,
A. Bizzeti,
V. Bocci, [......],
B. Schmidt,
T. Schneider,
B. Sciascia,
A. Sciubba,
N. Serra,
P. Shatalov,
S. Vecchi,
M. Veltri,
S. Volkov,
A. Vorobyev
[show abstract]
[hide abstract]
ABSTRACT: The performance of the LHCb Muon system and its stability across the full
2010 data taking with LHC running at ps = 7 TeV energy is studied. The
optimization of the detector setting and the time calibration performed with
the first collisions delivered by LHC is described. Particle rates, measured
for the wide range of luminosities and beam operation conditions experienced
during the run, are compared with the values expected from simulation. The
space and time alignment of the detectors, chamber efficiency, time resolution
and cluster size are evaluated. The detector performance is found to be as
expected from specifications or better. Notably the overall efficiency is well
above the design requirements
11/2012;
-
J. R. Batley,
A. J. Culling,
G. Kalmus,
C. Lazzeroni,
D. J. Munday,
M. W. Slater,
S. A. Wotton,
R. Arcidiacono,
G. Bocquet,
N. Cabibbo, [......],
F. Marchetto,
S. Bifani,
M. Clemencic,
S. Goy Lopez,
H. Dibon,
M. Jeitler,
M. Markytan,
I. Mikulec,
G. Neuhofer,
L. Widhalm
[show abstract]
[hide abstract]
ABSTRACT: We report the results from a study of the full sample of ∼6.031×107
K
±→π
±
π
0
π
0 decays recorded by the NA48/2 experiment at the CERN SPS. As first observed in this experiment, the π
0
π
0 invariant mass (M
00) distribution shows a cusp-like anomaly in the region around M
00=2m
+, where m
+ is the charged pion mass. This anomaly has been interpreted as an effect due mainly to the final state charge exchange scattering
process π
+
π
−→π
0
π
0 in K
±→π
±
π
+
π
− decay. Fits to the M
00 distribution using two different theoretical formulations provide the presently most precise determination of a
0−a
2, the difference between the π
π S-wave scattering lengths in the isospin I=0 and I=2 states. Higher-order π
π rescattering terms, included in the two formulations, allow also an independent, though less precise, determination ofa
2.
PACS13.25.Es-13.75.Lb-13.40.Ks-14.40.Aq
European Physical Journal C 04/2012; 64(4):589-608. · 3.63 Impact Factor
-
The Collaboration,
J. R. Batley,
G. Kalmus,
C. Lazzeroni,
D. J. Munday,
M. W. Slater,
S. A. Wotton,
R. Arcidiacono,
G. Bocquet,
N. Cabibbo, [......],
N. Cartiglia,
M. Clemencic,
S. Goy Lopez,
F. Marchetto,
H. Dibon,
M. Jeitler,
M. Markytan,
I. Mikulec,
G. Neuhofer,
L. Widhalm
[show abstract]
[hide abstract]
ABSTRACT: We report on the measurement of the direct emission (DE) and interference (INT) terms of the K
±→π
±
π
0
γ decay by the NA48/2 experiment at the CERN SPS. From the data collected during 2003 and 2004 about 600k such decay candidates
have been selected. The relative amounts of DE and INT with respect to the internal bremsstrahlung (IB) contribution have
been measured in the range $0
European Physical Journal C 04/2012; 68(1):75-87. · 3.63 Impact Factor
-
J.R. Batley,
A.J. Culling,
G. Kalmus,
C. Lazzeroni,
D.J. Munday,
M.W. Slater,
S.A. Wotton,
R. Arcidiacono,
G. Bocquet,
N. Cabibbo, [......],
M. Clemencic,
S. Goy Lopez,
F. Marchetto,
H. Dibon,
M. Jeitler,
M. Markytan,
I. Mikulec,
G. Neuhofer,
L. Widhalm,
The Collaboration
[show abstract]
[hide abstract]
ABSTRACT: We report results from a new measurement of the Ke4 decay K±→π+π-e±ν by the NA48/2 collaboration at the CERN SPS, based on a partial sample of more than 670 000 Ke4 decays in both charged modes collected in 2003. The form factors of the hadronic current (F,G,H) and ππ phase difference
(δ=δs-δp) have been measured in ten independent bins of the ππ mass spectrum to investigate their variation. A sizeable acceptance
at large ππ mass, a low background and a very good resolution contribute to an improved experimental accuracy, a factor two
better than in the previous measurement, when extracting the ππ scattering lengths a0
0 and a0
2. Under the assumption of isospin symmetry and using numerical solutions of the Roy equations, the following values are obtained
in the plane (a0
0,a0
2): a0
0=0.233±0.016stat±0.007syst,a0
2=-0.0471±0.011stat±0.004syst. The presence of potentially large isospin effects is also considered and will allow comparison
with precise predictions from Chiral Perturbation Theory.
European Physical Journal C 04/2012; 54(3):411-423. · 3.63 Impact Factor
-
The Collaboration,
J. R. Batley,
G. Kalmus,
C. Lazzeroni,
D. J. Munday,
M. W. Slater,
S. A. Wotton,
R. Arcidiacono,
G. Bocquet,
N. Cabibbo, [......],
F. Marchetto,
S. Bifani,
M. Clemencic,
S. Goy Lopez,
H. Dibon,
M. Jeitler,
M. Markytan,
I. Mikulec,
G. Neuhofer,
L. Widhalm
[show abstract]
[hide abstract]
ABSTRACT: We report results from the analysis of the $\mbox {$\mbox { ($\mbox {$\mbox {) decay by the NA48/2 collaboration at the CERN SPS, based on the total statistics of 1.13 million decays collected in 2003–2004.
The hadronic form factors in the S- and P-wave and their variation with energy are obtained. The phase difference between
the S- and P-wave states of the ππ system is accurately measured and allows a precise determination of $\mbox {$\mbox { and $\mbox {$\mbox {, the I = 0 and I = 2 S-wave ππ scattering lengths: $\mbox {$\mbox {. Combination of this result with the other NA48/2 measurement obtained in the study of $\mbox {$\mbox { decays brings an improved determination of $\mbox {$\mbox { and the first precise experimental measurement of $\mbox {$\mbox {, providing a stringent test of Chiral Perturbation Theory predictions and lattice QCD calculations. Using constraints based
on analyticity and chiral symmetry, even more precise values are obtained: $\mbox {$\mbox { and $\mbox {$\mbox {.
European Physical Journal C 04/2012; 70(3):635-657. · 3.63 Impact Factor
-
J R Batley,
G Kalmus,
C Lazzeroni,
D J Munday,
M W Slater,
S A Wotton,
R Arcidiacono,
G Bocquet,
N Cabibbo,
A Ceccucci, [......],
F Marchetto,
S Bifani,
M Clemencic,
S Goy Lopez,
H Dibon,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: A sample of more than one million (Ke4) decay candidates with less than one percent background contamination has been collected by the NA48/2 experiment at the CERN SPS in 2003-2004, allowing a detailed study of the decay properties. The branching ratio, inclusive of Ke4 decays, is measured to be with a total relative error of 0.8%. This measurement complements the study of S- and P-wave hadronic form factors by assigning absolute values to the relative hadronic form factors obtained earlier in a simultaneous analysis of the ππ scattering lengths conducted on the same data sample. The overall form factor normalization is obtained with a total relative precision of 0.6%. © 2012 Elsevier B.V.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 01/2012; 715(1-3):105-115.
-
J R Batley,
A J Culling,
G Kalmus,
C Lazzeroni,
D J Munday,
M W Slater,
S A Wotton,
R Arcidiacono,
G Bocquet,
N. Cabibbo, [......],
F Marchetto,
S. Bifani,
M Clemencic,
S Goy Lopez,
H Dibon,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: As first observed by the NA48/2 experiment at the CERN SPS, the $\p0p0$ invariant mass (M00) distribution from $\kcnn$ decay shows a cusp-like anomaly at M00=2m+, where m+ is the charged pion mass. An analysis to extract the pi pi scattering lengths in the isospin I=0 and I=2 states, a0 and a2, respectively, has been recently reported. In the present work the Dalitz plot of this decay is fitted to a new empirical parameterization suitable for practical purposes, such as Monte Carlo simulations of K+- -> pi+- pi0 pi0 decays. Comment: 9 pages, 3 figures.
04/2010;
-
J R Batley,
G E Kalmus,
C Lazzeroni,
D J Munday,
M Patel,
M W Slater,
S A Wotton,
R Arcidiacono,
G Bocquet,
A Ceccucci, [......],
N Pastrone,
M Clemencic,
S G Lopez,
E Menichetti,
W Wislicki,
H Dibon,
M Jeitler,
M Markytan,
G Neuhofer,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: A total of 368 415 Ξ 0 → Λ π 0 and 31 171 over(Ξ 0, -) → over(Λ, -) π 0 were selected from data recorded in the NA48/1 experiment during 2002 data taking. From this sample, the polarization of Ξ 0 and over(Ξ 0, -) hyperons was measured to be P Ξ0 = - 0.102 ± 0.012 (stat) ± 0.008 (syst) and P over(Ξ0, -) = - 0.01 ± 0.04 (stat) ± 0.008 (syst). The dependence of P Ξ0 on the Ξ 0 transverse momentum with respect to the primary proton beam is also presented. With the same data sample, the ratio of over(Ξ 0, -) and Ξ 0 fluxes in proton collisions at 400 GeV / c on a beryllium target was measured. © 2009 Elsevier B.V. All rights reserved.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 01/2009; 681(5):406-412.
-
J.R. Batley,
A.J. Culling,
G. Kalmus,
C. Lazzeroni,
D.J. Munday,
M.W. Slater,
S.A. Wotton,
R. Arcidiacono,
G. Bocquet,
N. Cabibbo, [......],
M. Clemencic,
S. Goy Lopez,
F. Marchetto,
H. Dibon,
M. Jeitler,
M. Markytan,
I. Mikulec,
G. Neuhofer,
L. Widhalm,
The Collaboration
[show abstract]
[hide abstract]
ABSTRACT: A measurement of the direct CP violating charge asymmetries of the Dalitz plot linear slopes Ag=(g+-g-)/(g++g-) in K±→π±π+π- and K±→π±π0π0 decays by the NA48/2 experiment at CERN SPS is presented. A new technique of asymmetry measurement involving simultaneous
K+ and K- beams and a large data sample collected allowed a result of an unprecedented precision. The charge asymmetries were measured
to be Ac
g=(-1.5±2.2)×10-4 with 3.11×109K±→π±π+π- decays, and An
g=(1.8±1.8)×10-4 with 9.13×107K±→π±π0π0 decays. The precision of the results is limited mainly by the size of the data sample.
European Physical Journal C 11/2007; 52(4):875-891. · 3.63 Impact Factor
-
J.R. Batley,
C. Lazzeroni,
D.J. Munday,
M.W. Slater,
S.A. Wotton,
R. Arcidiacono,
G. Bocquet,
N. Cabibbo,
A. Ceccucci,
D. Cundy, [......],
M. Clemencic,
S. Goy Lopez,
F. Marchetto,
H. Dibon,
M. Jeitler,
M. Markytan,
I. Mikulec,
G. Neuhofer,
L. Widhalm,
The Collaboration
[show abstract]
[hide abstract]
ABSTRACT: Measured ratios of decay rates for RK e 3 / K2p{\mathcal{R}}_{K e 3 / K2\pi}, RK m3 / K2p{\mathcal{R}}_{K \mu3 / K2\pi} and RK m3 / Ke3{\mathcal{R}}_{K \mu3 / Ke3} are presented. These measurements are based on K± decays collected in a dedicated run in 2003 by the NA48/2 experiment at CERN. The results obtained are
RK e 3 / K2p = 0.2496±0.0009 (\textstat)±0.0004 (\textsyst){\mathcal{R}}_{K e 3 / K2\pi} = 0.2496\pm0.0009 ({\text{stat}})\pm0.0004 ({\text{syst}}) and
RK m3 / K2p = 0.1637±0.0006 (\textstat)±0.0003 (\textsyst){\mathcal{R}}_{K \mu3 / K2\pi} = 0.1637\pm0.0006 ({\text{stat}})\pm0.0003 ({\text{syst}}). Using the PDG average for the K±→π±π0 normalisation mode, both values are found to be larger than the current values given by the particle data book and lead to
a larger magnitude of the |Vus| CKM element than previously accepted. When combined with the latest particle data book value of |Vud|, the result is in agreement with unitarity of the CKM matrix. In addition, a new measured value of
RK m3 / Ke3 = 0.656±0.003(\textstat)±0.001(\textsyst){\mathcal{R}}_{K \mu3 / Ke3} = 0.656\pm0.003({\text{stat}})\pm0.001({\text{syst}}) is compared to the semi-empirical predictions based on the latest form factor measurements.
European Physical Journal C 03/2007; 50(2):329-340. · 3.63 Impact Factor
-
Collaboration,
J R Batley,
G E Kalmus,
C Lazzeroni,
D J Munday,
M Patel,
M W Slater,
S A Wotton,
R Arcidiacono,
G Bocquet, [......],
P Marouelli,
U Moosbrugger,
C Morales,
A Peters,
R Wanke,
A Winhart,
A Dabrowski,
T Fonseca,
S Goy Lopez,
M Velasco
Physics Letters B. 01/2007; 653:145-150.
-
J R Batley,
C Lazzeroni,
D J Munday,
M W Slater,
S A Wotton,
R Arcidiacono,
G Bocquet,
N Cabibbo,
A Ceccucci,
D Cundy, [......],
N Cartiglia,
M Clemencic,
S Goy Lopez,
F Marchetto,
H Dibon,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
L Widhalm
European Physical Journal C. 01/2007; 52(4):1021-1023.
-
A Lai,
D Marras,
A Bevan,
R S Dosanjh,
T J Gershon,
B Hay,
G E Kalmus,
C Lazzeroni,
D J Munday,
E Olaiya, [......],
S Wronka,
H Dibon,
G Fischer,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
M Pernicka,
A Taurok,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: This Letter reports on a new high precision measurement of the form factors of the KL → π± μ∓ νμ decay. The data sample of about 2.3 × 106 events was recorded in 1999 by the NA48 experiment at CERN. Studying the Dalitz plot density we measured a linear, λ+ ′ = (20.5 ± 2.2stat ± 2.4syst) × 10-3, and a quadratic, λ+ ″ = (2.6 ± 0.9stat ± 1.0syst) × 10-3 term in the power expansion of the vector form factor. No evidence was found for a second order term for the scalar form factor; the linear slope was determined to be λ0 = (9.5 ± 1.1stat ± 0.8syst) × 10-3. Using a linear fit our results were: λ+ = (26.7 ± 0.6stat ± 0.8syst) × 10-3 and λ0 = (11.7 ± 0.7stat ± 1.0syst) × 10-3. A pole fit of the form factors yields: mV = (905 ± 9stat ± 17syst) MeV / c2 and mS = (1400 ± 46stat ± 53syst) MeV / c2. © 2007 Elsevier B.V. All rights reserved.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 01/2007; 647(5-6):341-350.
-
J R Batley,
G E Kalmus,
C Lazzeroni,
D J Munday,
M Patel,
M W Slater,
S A Wotton,
R Arcidiacono,
G Bocquet,
A Ceccucci, [......],
M Clemencic,
S Goy Lopez,
E Menichetti,
N Pastrone,
W Wislicki,
H Dibon,
M Jeitler,
M Markytan,
G Neuhofer,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: From 56 days of data taking in 2002, the NA48/1 experiment observed 6316 Ξ0 → Σ+ e- over(ν, ̄)e candidates (with the subsequent Σ+ → p π0 decay) and 555 over(Ξ0, -) → over(Σ+, -) e+ νe candidates with background contamination of 215 ± 44 and 136 ± 8 events, respectively. From these samples, the branching ratios BR (Ξ0 → Σ+ e- over(ν, ̄)e) = (2.51 ± 0.03stat ± 0.09syst) × 10-4 and BR (over(Ξ0, -) → over(Σ+, -) e+ νe) = (2.55 ± 0.14stat ± 0.10syst) × 10-4 were measured allowing the determination of the CKM matrix element | Vus | = 0.209-0.028 +0.023. Using the Particle Data Group average for | Vus | obtained in semileptonic kaon decays, we measured the ratio g1 / f1 = 1.20 ± 0.05 of the axial-vector to vector form factors. © 2006 Elsevier B.V. All rights reserved.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 01/2007; 645(1):36-46.
-
A Lai,
D Marras,
A Bevan,
R S Dosanjh,
T J Gershon,
B Hay,
G E Kalmus,
C Lazzeroni,
D J Munday,
M D Needham, [......],
S Wronka,
H Dibon,
G Fischer,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
M Pernicka,
A Taurok,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: The decay rate of the long-lived neutral K meson into the e +e -e +e - final state has been measured with the NA48 detector at the CERN SPS. Using data collected in 1998 and 1999, a total of 200 events has been observed with negligible background. This observation corresponds to a branching ratio of Br(K L→ e +e -e +e -)=(3.30±0.24 stat±0.23 syst±0.10 norm) ×10 -8. © 2005 Elsevier B.V. All rights reserved.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 01/2005; 615(1-2):31-38.
-
J. R. Batley,
R. S. Dosanjh,
T. J. Gershon,
G. E. Kalmus,
C. Lazzeroni,
D. J. Munday,
E. Olaiya,
M. Patel,
M. A. Parker,
T. O. White, [......],
E. Rondio,
W. Wiślicki,
S. Wronka,
H. Dibon,
M. Jeitler,
M. Markytan,
G. Neuhofer,
M. Pernicka,
A. Taurok,
L. Widhalm
[show abstract]
[hide abstract]
ABSTRACT: The
KL-->π+/-π0e-/+νe(ν¯e)
decay was investigated with the NA48 detector at CERN SPS using a beam
of long-lived neutral kaons. The branching ratio
Br(KL-->π+/-π0e-/+νe(ν¯e))=(5.21+/-0.07stat+/-0.09syst)×10-5
was fixed from a sample of 5464 events with 62 background events. The
form factors f¯s, f¯p,
λg and h¯ were found to be in agreement with
previous measurements but with higher accuracy. The coupling parameter
of the chiral Lagrangian
L3=(-4.1+/-0.2)×10-3 was evaluated from the
data.
Funded by the Austrian Ministry of Education, Science and Culture under
contract GZ 616.360/2-IV GZ 616.363/2-VIII, and by the Fund for
Promotion of Scientific Research in Austria (FWF) under contract
P08929-PHY.
Physics Letters B 07/2004; 595:75-85. · 3.95 Impact Factor
-
A Lai,
D Marras,
A Bevan,
R S Dosanjh,
T J Gershon,
B Hay,
G E Kalmus,
C Lazzeroni,
D J Munday,
E Olaiya, [......],
S Wronka,
H Dibon,
G Fischer,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
M Pernicka,
A Taurok,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: The semileptonic decay of the neutral K meson, KL0→π± e∓ν (Ke3), was used to study the strangeness-changing weak interaction of hadrons. A sample of 5.6 million reconstructed events recorded by the NA48 experiment was used to measure the Dalitz plot density. Admitting all possible Lorentz-covariant couplings, the form factors for vector (f+(q2)), scalar (fS) and tensor (fT) interactions were measured. The linear slope of the vector form factor λ+=0.0284±0.0007±0.0013 and values for the ratios |fS/f+(0)|=0.015-0.010+0.007±0.012 and |fT/f+(0)|=0.05-0.04+0. 03±0.03 were obtained. The values for fS and fT are consistent with zero. Assuming only vector-axial-vector couplings, λ+=0.0288±0. 0004±0.0011 and a good fit consistent with pure V-A couplings were obtained. Alternatively, a fit to a dipole form factor yields a pole mass of M=859±18 MeV, consistent with the K*(892) mass. © 2004 Elsevier B.V. All rights reserved.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 01/2004; 604(1-2):1-10.
-
A Lai,
D Marras,
J R Batley,
R S Dosanjh,
T J Gershon,
G E Kalmus,
C Lazzeroni,
D J Munday,
E Olaiya,
M A Parker, [......],
W Wislicki,
S Wronka,
H Dibon,
M Jeitler,
M Markytan,
I Mikulec,
G Neuhofer,
M Pernicka,
A Taurok,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: Using the NA48 detector at the CERN SPS, 31 KS → π 0γγ candidates with an estimated background of 13.7 ± 3.2 events have been observed. This first observation leads to a branching ratio of BR(KS → π0γγ) z>0.2 = (4.9 ± 1.6stat ± 0.9 syst) × 10-8 in agreement with Chiral Perturbation Theory predictions. © 2003 Elsevier B.V. All rights reserved.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics. 01/2004; 578(3-4):276-284.
-
A Lai,
D Marras,
A Bevan,
R S Dosanjh,
T J Gershon,
B Hay,
G E Kalmus,
C Lazzeroni,
D J Munday,
M D Needham, [......],
M Szleper,
W Wislicki,
S Wronka,
G Fischer,
M Jeitler,
M Markytan,
G Neuhofer,
M Pernicka,
A Taurok,
L Widhalm
[show abstract]
[hide abstract]
ABSTRACT: The KL → π+π-e +e- and KS → π+π -e+e- decay modes have been studied in detail using the NA48 detector at the CERN SPS. Based on the data collected during the 1998 and 1999 run periods, a sample of 1162 KL → π +π-e+e- candidates has been observed with an expected background level of 36.9 events, yielding the branching ratio measurement BR(KL → π+π -e+e-) = (3.08 ± 0.20) × 10 -7. The distribution of events in the sinφ cosφ variable, where φ is the angle between the π+π- and the e+e- decay planes in the kaon centre of mass, is found to exhibit a large CP-violating asymmetry with the value Aφ = (14.2 ± 3.6)%. For the KS → π+π -e+e- decay channel, 621 candidates have been identified in the 1999 data sample with an estimated background contribution of 0.7 event. The corresponding branching ratio has been determined to be BR(K S → π+π-e+e-) = (4.71 ± 0.32) × 10-5. The combined value of this measurement with the published 1998 result is BR(KS → π +π-e+e-) = (4.69 ± 0.30) × 10-5. No asymmetry is observed in this decay mode. Our results are in good agreement with theoretical predictions based on a phenomenological description of radiative kaon decays. The form factor parameters a1/a2 and g̃M1 in the K L → π+π-e+e- direct emission process as well as the value of the K0 charge radius have been extracted from the data.
European Physical Journal C. 01/2003; 30(1):33-49.
