First observation of a particle - anti-particle asymmetry in the decay of neutral kaons into pi0 pi0

The CPLEAR collaboration Adler, R. ; Alhalel, T. ; Angelopoulos, A. ; et al.
Z.Phys.C 70 (1996) 211-218, 1996.
Inspire Record 399741 DOI 10.17182/hepdata.48092

CP violation has been observed as a time-dependent rate asymmetry between the decays ${⩈erline K}^0 ⌝ghtarrow ≪^{0} ≪^{0}$ and K0 → π0π{0}, where the neutral kaons are produced with definite and individually known strangeness in ${⋏r p}p ⌝ghtarrow{⩈erline K}^0 K^+≪^- $ or p̅p → K0 K− π+. A special technique for the data analysis has been developed. The values obtained for ϕ00 and ¦ η00¦ are in agreement with those of previous measurements of CP violation.

1 data table

No description provided.


Measurement of K(L) - K(S) mass difference using semileptonic decays of tagged neutral kaons

The CPLEAR collaboration Adler, R. ; Alhalel, T. ; Angelopoulos, A. ; et al.
Phys.Lett.B 363 (1995) 237-242, 1995.
Inspire Record 398337 DOI 10.17182/hepdata.52370

We present a new measurement of the K L -K S mass difference ( Δm ) using semileptonic decays of neutral kaons. The measurement yields Δm = (0.5274 ± 0.0029 stat. ± 0.0005 syst. ) × 10 10 ħ/s.

1 data table

No description provided.


Determination of the relative branching ratios for p anti-p ---> pi+ pi- and p anti-p ---> K+ K-

The CPLEAR collaboration Adler, R. ; Angelopoulos, A. ; Apostolakis, A. ; et al.
Phys.Lett.B 267 (1991) 154-158, 1991.
Inspire Record 317491 DOI 10.17182/hepdata.48425

The ratio of the branching fractions for p p →K + K − and p p →π + π − was determined with the CPLEAR detector, by stopping antiprotons in a gaseous hydrogen target at 15 bar pressure. It was found to be BR(K + K − )/BR( π + π − )=0.205± 0.016. The fraction of P-wave annihilation at rest at this target density was deduced to be (38±9)%.

1 data table

CONST is the fraction of P-wave annihilation in gaseous hydrogen at pressu re of 15 bar. In the SIG/SIG the statistical and systematic errors are added qu adratically.