A
bstract
The quantum interference between the decays of entangled neutral kaons is studied in the process
ϕ
→ K
S
K
L
→
π
+
π
−
π
+
π
−
, which exhibits the characteristic Einstein-Podolsky-Rosen ...correlations that prevent both kaons to decay into
π
+
π
−
at the same time. This constitutes a very powerful tool for testing at the utmost precision the quantum coherence of the entangled kaon pair state, and to search for tiny decoherence and
CPT
violation effects, which may be justified in a quantum gravity framework.
The analysed data sample was collected with the KLOE detector at DAΦNE, the Frascati
ϕ
-factory, and corresponds to an integrated luminosity of about 1.7 fb
−
1
, i.e. to about 1
.
7 × 10
9
ϕ
→ K
S
K
L
decays produced. From the fit of the observed ∆
t
distribution, being ∆
t
the difference of the kaon decay times, the decoherence and
CPT
violation parameters of various phenomenological models are measured with a largely improved accuracy with respect to previous analyses.
The results are consistent with no deviation from quantum mechanics and
CPT
symmetry, while for some parameters the precision reaches the interesting level at which — in the most optimistic scenarios — quantum gravity effects might show up. They provide the most stringent limits up to date on the considered models.
—
A new method of digital mapping of the soil cover pattern with calculation of the share of soils of different taxa and degree classes for soil erosion in the soil associations is proposed. A ...comparative analysis of soil maps obtained using different methods of construction (visual expert and digital) and with their different contents (displaying the dominant soil or soil associations) has been performed. In the case of mapping by the visual expert method (with the display of the dominant soil), a significant underestimation of the total area of moderately and strongly eroded soils in comparison with the digital mapping is noted. These differences are due to the underestimation of the area of small polygons with moderately and strongly eroded soils in the composition of soil associations on slopes of low steepness and in shallow hollows in the visual expert method of mapping. When the content of digital maps is generalized from soil associations to dominant soil categories, a significant change in information on the degree of soil degradation by erosion is also noted. Comparison of visual expert and digital methods for mapping soils of different taxa indicates a high degree of compliance between the spatial location and area of soil delineations with similar component content in both cases. The greatest differences between the soil maps created by these methods are noted for the soils with periodic overmoistening, namely, meadow-chernozemic (Luvic Chernic Phaeozem (Oxyaquic)) and chernozemic-meadow (Luvic Stagnic Chernic Phaeozem) soils because of the poor consideration for microtopography in traditional mapping. In general, it can be concluded that the creation of a digital map is more difficult in terms of the need to use specialized computer programs and mathematical models. However, the resulting digital databases contain information of a higher level of detail than traditional soil maps.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We propose an optical correlation algorithm illustrating a new general method for reconstructing the phase skeleton of complex optical fields from the measured two-dimensional intensity distribution. ...The core of the algorithm consists in locating the saddle points of the intensity distribution and connecting such points into nets by the lines of intensity gradient that are closely associated with the equi-phase lines of the field. This algorithm provides a new partial solution to the inverse problem in optics commonly referred to as the phase problem.
The possibility of correcting the amplitude–phase distortions of Laguerre–Gauss laser beams on atmospheric paths is investigated using computer simulation. The adaptive correction scheme is used ...based on the principle of phase conjugation of the reference wave from an auxiliary coherent source. The propagation of beams in a randomly heterogeneous medium with a power-law spatial spectrum typical of atmospheric turbulence is simulated by solving numerically of the inhomogeneous parabolic wave equation. The scalar wave equation is solved by the Fourier splitting method using the parallel architecture algorithms. The effect of atmospheric turbulence on orbital angular momentum fluctuations of the Laguerre–Gauss vortex beams is considered; the possibility of correction of these fluctuations is proved theoretically, and its efficiency is estimated using an adaptive optical phase conjugation system. The role of Academician Basov in the organization of systematic study of propagation of coherent optical waves in the atmosphere as a randomly inhomogeneous medium is indicated.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The process e+e−→K+K− has been studied using 1.7×106 events from a data sample corresponding to an integrated luminosity of 5.7 pb−1 collected with the CMD-3 detector in the center-of-mass energy ...range 1010–1060 MeV. The cross section is measured with about 2% systematic uncertainty and is used to calculate the contribution to the anomalous magnetic moment of the muon aμK+K−=(19.33±0.40)×10−10, and to obtain the ϕ(1020) meson parameters. We consider the relationship between the e+e−→K+K− and e+e−→KS0KL0 cross sections and compare it to the theoretical prediction.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Abstract
A high degree of cross-correlation of radiation wavefront aberrations, measured from a point reference source and from an extended object (a system of several luminous points), has been for ...the first time revealed based on simultaneous measurements of phase fluctuations in optical waves propagating in a turbulent atmosphere. The experimental data are consistent with analytical calculations. The high degree of cross-correlation (above 0.97) of measured phase fluctuations proves that an extended incoherent source can be used as a reference source to ensure the operation of an adaptive focusing system.
A
bstract
Using 1.63 fb
−1
of integrated luminosity collected by the KLOE experiment about 7 × 10
4
K
S
→
π
±
e
∓
ν
decays have been reconstructed. The measured value of the charge asymmetry for this ...decay is
A
S
= (−4.9 ± 5.7
stat
± 2.6
syst
) × 10
−3
, which is almost twice more precise than the previous KLOE result. The combination of these two measurements gives
A
S
= (−3.8 ± 5.0
stat
± 2.6
syst
) × 10
−3
and, together with the asymmetry of the
K
L
semileptonic decay, provides significant tests of the
CPT
symmetry. The obtained results are in agreement with
CPT
invariance.
A
bstract
Based on an integrated luminosity of 1.61 fb
−
1
e
+
e
−
collision data collected with the KLOE detector at DAΦNE, the Frascati
ϕ
-factory, a search for the
P
- and
CP
-violating decay
η → ...π
+
π
−
has been performed. Radiative
ϕ → ηγ
decay is exploited to access the
η
mesons. No signal is observed in the
π
+
π
−
invariant mass spectrum, and the upper limit on the branching fraction at 90% confidence level is determined to be ℬ(
η → π
+
π
−
)
<
4
.
9
×
10
−
6
, which is approximately three times smaller than the previous KLOE result. From the combination of these two measurements we get ℬ(
η → π
+
π
−
)
<
4
.
4
×
10
−
6
at 90% confidence level.
We searched for the μ+μ− decay of a light vector gauge boson, also known as dark photon, in the e+e−→μ+μ−γISR process by means of the Initial State Radiation (ISR) method. We used 1.93 fb−1 of data ...collected by the KLOE experiment at the DAΦNE ϕ-factory. No structures have been observed over the irreducible μ+μ− background. A 90% CL limit on the ratio ε2=α′/α between the dark coupling constant and the fine structure constant of 3×10−6–2×10−7 has been set in the dark photon mass region between 519 MeV and 973 MeV. This new limit has been combined with the published result obtained investigating the hypothesis of the dark photon decaying into hadrons in e+e−→π+π−γISR events. The combined 90% CL limit increases the sensitivity especially in the ρ–ω interference region and excludes ε2 greater than (13−2)×10−7. For dark photon masses greater than 600 MeV the combined limit is lower than 8 ×10−7 resulting more stringent than present constraints from other experiments.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Based on a sample of 300 million KS mesons produced in ϕ→KLKS decays recorded by the KLOE experiment at the DAΦNE e+e− collider we have measured the branching fraction for the decay KS→πμν. The KS ...mesons are identified by the interaction of KL mesons in the detector. The KS→πμν decays are selected by a boosted decision tree built with kinematic variables and by a time-of-flight measurement. Signal efficiencies are evaluated with data control samples of KL→πμν decays. A fit to the reconstructed muon mass distribution finds 7223±180 signal events. Normalising to the KS→π+π− decay events the result for the branching fraction is B(KS→πμν)=(4.56±0.11stat±0.17syst)×10−4. It is the first measurement of this decay mode and the result allows an independent determination of |Vus| and a test of the lepton-flavour universality.
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Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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