65 research outputs found
Measurement of the Dalitz plot slope parameters for K- -> pi0 pi0 pi- decay using ISTRA+ detector
The Dalitz plot slope parameters g, h and k for the K- -> pi0 pi0 pi- decay
have been measured using in-flight decays detected with the ISTRA+ setup
operating in the 25 GeV negative secondary beam of the U-70 PS. About 252 K
events with four-momenta measured for the pi- and four involved photons were
used for the analysis. The values obtained g=0.627+/-0.004(stat)+/-0.010(syst),
h=0.046+/-0.004(stat)+/-0.012(syst), k=0.001+/-0.001(stat)+/-0.002(syst) are
consistent with the world averages dominated by K+ data, but have significantly
smaller errors.Comment: LaTeX, 10 pages, 8 eps-figures, update of IHEP 2002-1
High statistics study of the K- -> pi0 e- nu decay
The decay K- -> pi0 e- nu has been studied using in-flight decays detected
with the "ISTRA+" spectrometer working at the 25 GeV negative secondary beam of
the U-70 PS. About 550K events were used for the analysis. The lambda+
parameter of the vector form-factor has been measured: lambda+ = 0.0286 +-
0.0008 (stat) +- 0.0006(syst). The limits on the possible tensor and scalar
couplings have been obtained: f(T)/f+(0)=0.021 +0.064 -0.075 (stat) +-
0.026(syst) ; f(S)/f+(0)=0.002 +0.020 -0.022 (stat) +- 0.003(syst)Comment: LaTeX-2e, epsfig.sty, 10 pages, 7 figures in EPS forma
Charged Kaon K \to 3 pi CP Violating Asymmetries at NLO in CHPT
We give the first full next-to-leading order analytical results in Chiral
Perturbation Theory for the charged Kaon K \to 3 pi slope g and decay rates
CP-violating asymmetries. We have included the dominant Final State
Interactions at NLO analytically and discussed the importance of the unknown
counterterms. We find that the uncertainty due to them is reasonable just for
\Delta g_C, i.e. the asymmetry in the K^+ \to pi^+ pi^+ pi^- slope g; we get
\Delta g_C = -(2.4 +- 1.2) 10^{-5}. The rest of the asymmetries are very
sensitive to the unknown counterterms. In particular, the decay rate
asymmetries can change even sign. One can use this large sentivity to get
valuable information on those counterterms and on Im(G_8) coupling --very
important for the CP-violating parameter epsilon'_K-- from the eventual
measurement of these asymmetries. We also provide the one-loop O(e^2 p^2)
electroweak octet contributions for the neutral and charged Kaon K \to 3 pi
decays.Comment: 43+2 pages, 2 figures. Version accepted in JHEP. Small changes in the
final numerics of CP asymmetries due to change in input valu
Inclusive production of protons, anti-protons and neutrons in p+p collisions at 158 GeV/c beam momentum
New data on the production of protons, anti-protons and neutrons in p+p
interactions are presented. The data come from a sample of 4.8 million
inelastic events obtained with the NA49 detector at the CERN SPS at 158 GeV/c
beam momentum. The charged baryons are identified by energy loss measurement in
a large TPC tracking system. Neutrons are detected in a forward hadronic
calorimeter. Inclusive invariant cross sections are obtained in intervals from
0 to 1.9 GeV/c (0 to 1.5 GeV/c) in transverse momentum and from -0.05 to 0.95
(-0.05 to 0.4) in Feynman x for protons (anti-protons), respectively. pT
integrated neutron cross sections are given in the interval from 0.1 to 0.9 in
Feynman x. The data are compared to a wide sample of existing results in the
SPS and ISR energy ranges as well as to proton and neutron measurements from
HERA and RHIC.Comment: 69 pages, 72 figure
Energy and quantum number flow in K+p and π+p interactions at 32 and 70 GeV/c
Energy, charge and strangeness flow in K+p interactions at 32 and 70 GeV/c, and π+p interactions at 32 GeV/c are studied in terms of the angular variable λ=0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Inclusive Λ polarization in K+p interactions at 32 and 70 GeV/c
We present results on the inclusive polarization of Λ hyperons produced in K+p interactions at 32 and 70 GeV/c. A large positive Λ polarization is observed in the kaon fragmentation region. The polarization is energy independent, increases strongly with increasing x, but shows essentially no pT-dependence. © 1983.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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