Energy dependence of beta-gamma directional correlation in the decay of Lu177

The directional correlations for the 174 keV-beta and the 208 keV-gamma cascade and for the 384 keV-beta and the 113 keV-gamma cascade in the decay of Lu¹⁷⁷ have been measured as a function of the energy of the beta-particles. A magnetic lens spectrometer was used to select the energy of the beta-rays. For the first cascade the observed correlation is isotropic. For the 384 keV-beta and the 113 keV-gamma cascade, the anisotropy factorA ₂(W) in the beta-gamma directional correlation\(W_{\beta _\gamma } (\vartheta ,W) = 1 + A_2 (W)P_2 (\cos \vartheta )\) is proportional toP ²/W and its value isA ₂ (1.48)=+0.0575±0.0068. The analysis of the data shows that theξ-approximation for first-forbidden nonunique beta transitions represents the results of the 384 keV-beta and the 113 keV-gamma cascade in a very satisfactory manner.     

The 198Au βhalf-life in the metal Au⋆

For the β^--decay of ¹⁹⁸Au in a Au metallic environment the half-life was observed to be longer by 0.4±0.7% at room temperature (T = 293K) and by 4.0±0.7% when the metal was cooled to T = 12K, both compared to the literature value of T _1/2 = 2.6943±0.0008d.     

Experimental evidence of anomalous phase synchronization in two diffusively coupled Chua oscillators

We study the transition to phase synchronization in two diffusively coupled, nonidentical Chua oscillators. In the experiments, depending on the used parameterization, we observe several distinct routes to phase synchronization, including states of either in-phase, out-of-phase, or antiphase synchronization, which may be intersected by an intermediate desynchronization regime with large fluctuations of the frequency difference. Furthermore, we report the first experimental evidence of an anomalous transition to phase synchronization, which is characterized by an initial enlargement of the natural frequency difference with coupling strength. This results in a maximal frequency disorder at intermediate coupling levels, whereas usual phase synchronization via monotonic decrease in frequency difference sets in only for larger coupling values. All experimental results are supported by numerical simulations of two coupled Chua models.     

Beta-gamma-gamma directional correlation in103Rh

β-γ-γ directional correlation studies for the cascades (i)β-rays ofE _max=0.12 MeV,γ-rays of 557 keV andγ-rays of 53 keV and (ii)β-rays ofE _max=0.21 MeV,γ-rays of 444 keV andγ-rays of 53 keV have been made. The triple correlation functionsW(θ) were obtained to beW(θ)=1+(−0.153±0.031)P ₂(cosθ)+(0.004±0.035)P ₄(cosθ) forβ-rays ofE _max 0.12 MeV→557→53 keV cascade andW(θ)=1+(0.163±0.042)P ₂(cosθ)+(−0.035±0.058)P ₄(cosθ) forβ rays ofE _max=0.21 MeV→444 keV→53 keV cascade. Spins and parities of the 650, 537 and 93 keV levels of¹⁰³Rh are deduced by triple angular correlation and the internal conversion coefficient studies. Multipolarities of the transitions are also determined.     

Experimental evidence for spin diffusion of four-spin correlation functions in a one-dimensional heisenberg magnet

The EPR magic angle linewidth and dynamic shift have been measured as a function of frequency in TMMC. Both the linewidth and the shift vary with frequency as $\text{ω}{}^{\mathrm{<mtext>?</mtext><mtext>1</mtext><mtext>2</mtext>}}$. These results support strongly the one-dimensional behaviour of the relaxation dynamics of this compound. The results are in good agreement with a recent calculation.     

Gamma-gamma directional correlation measurements in192Os

E2/M1 mixing ratios of transitions in¹⁹²Os have been determined by the gammagamma directional correlation technique. The results are: δ(484.5 keV)= ?10±1, δ(283.3 keV)= ?3.8± 0.7 and δ(201.3 keV)= ?4.6±1.     

Gamma-gamma directional correlation study in92Zr

The gamma-gamma directional correlation of the 2⁺′-2⁺-0⁺, 913(Iγ=1.69)-934(Iγ =100)keV cascade in⁹²Nb decay has been investigated with a NaI-Ge(Li) system. Our results yieldδ=?0.013 _?0.024 ^+0.041 . This is one of a very few cases where the second 2⁺ to first 2⁺ transition is not predominatelyE2. This may be related to the closed neutron shell, as earlier suggested. [Radioactivity⁹²Zr; measuredγ-γ(θ), deducedδ]     

Photon-electron directional correlation in muonic atoms and weak-interaction models

Measurements of photon-electron directional correlation in muonic atoms may provide useful information on the low-energy neutral-current effective interaction of charged leptons with light quarks, significantly complementing the information obtainable from other low-energy parity-violation experiments. We calculate the expectations for the correlation coefficients in conventional extended gauge models, such as to test for possible deviations with respect to the standard model. We discuss sources of uncertainty in the estimate of such deviations. The physical relevance of this analysis is exhibited in a number of graphs which illustrate how such experiments, at presumably attainable precision, would significantly improve the bounds on the effective lagrangian as obtained from other sets of data (including LEP).     

Di-jet correlation in Au+Au and Cu+Cu Collisions from PHENIX

PHENIX has measured the two-particle azimuth correlation in Au+Au at √s=200 GeV. Jet shape and yield at the away side are found to be strongly modified at intermediate and low p _T, and the modifications vary dramatically with p _T and centrality. At high p _T, away side jet peak reappears but the yield is suppressed. Similar jet strength is found for Au+Au and Cu+Cu collisions with similar number of participant nucleons.     

Experimental evidence for anomalous L/M conversion ratio of the 2+→0+ transitions in some deformed even-even nuclei

TheL-subshell andM conversion coefficients ratios of the 2⁺→0⁺ transitions in some deformed even-even nuclei have been determined using a high resolution iron free double focusing beta-ray spectrometer. All possible uncertainties in these measurements have been minimized and properly evaluated. TheL ₁+L ₁₁/L ₁₁₁ ratios for the 2⁺→0⁺ E2 transitions in Dy¹⁶⁰, Er¹⁶⁶, Yb¹⁷⁰, Hd¹⁷⁶ and W¹⁸² are found to be in agreement with the theoretical ones within an experimental error of about 4%. However, large deviations from the theory of about two order of magnitude are observed forL/M conversion ratios. The deviations indicate the possibility of considerable approximation in the theoretical calculation of theM-internal conversion coefficients.     

Experimental evidence for soliton explosions

We show, experimentally and numerically, that Ti:sapphire mode-locked lasers can operate in a regime in which they intermittently produce exploding solitons. This happens when the laser operates near a critical point. Explosions happen spontaneously, but external perturbations can trigger them. In stable operation, all explosions have similar features, but are not identical. The characteristics of the explosions depend on the intracavity dispersion.