Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userObservation of Parity Violation in the Omega-minus -> Lambda + K-minus Decay
55
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The alpha decay parameter in the process Omega-minus -> Lambda + K-minus has been measured from a sample of 4.50 million unpolarized Omega-minus decays recorded by the HyperCP (E871) experiment at Fermilab and found to be [1.78 +/- 0.19(stat) +/- 0.16(syst)]{times}10^{-2}. This is the first unambiguous evidence for a nonzero alpha decay parameter, and hence parity violation, in the Omega-minus -> Lambda + K-minus decay.
rate research
Read More
We have measured the alpha parameter of the Omega- to Lambda K- decay using data collected with the HyperCP spectrometer during the 1997 fixed-target run at Fermilab. Analyzing a sample of 0.96 million Omega- to Lambda K^-, Lambda to p pi- decays, we obtain alpha_Omega*alpha_Lambda = [1.33+/-0.33(stat)+/-0.52(syst)] x 10^{-2}. With the accepted value of alpha_Lambda, alpha_Omega is found to be [2.07+/-0.51(stat)+/-0.81(syst)] x 10^{-2}.
A search for $C!P$ violation in the decay $Lambda^0_b to p K^- mu^+ mu^-$ is presented. This decay is mediated by flavour-changing neutral-current transitions in the Standard Model and is potentially sensitive to new sources of $C!P$ violation. The study is based on a data sample of proton-proton collisions recorded with the LHCb experiment, corresponding to an integrated luminosity of $3$ $mathrm{fb}^{-1}$. The $Lambda^0_b to p K^- mu^+ mu^-$ decay is observed for the first time, and two observables that are sensitive to different manifestations of $C!P$ violation are measured, $Deltamathcal{A}_{C!P} equiv mathcal{A}_{C!P}(Lambda^0_b to p K^- mu^+ mu^-)-mathcal{A}_{C!P}(Lambda^0_bto pK^- J/psi)$ and $a_{C!P}^{widehat{T}-odd}$, where the latter is based on asymmetries in the angle between the $mu^+mu^-$ and $p K^-$ decay planes. These are measured to be $Deltamathcal{A}_{C!P} = (-3.5 pm 5.0(stat) pm 0.2(syst))times 10^{-2}$, $a_{C!P}^{widehat{T}-odd} = (1.2 pm 5.0(stat) pm 0.7(syst))times 10^{-2}$, and no evidence for $C!P$ violation is found.
We report the observation of the baryonic B decay B0bar --> Lambda_c^+ anti-Lambda K- with a significance larger than 7 standard deviations based on 471x10^6$ BBbar pairs collected with the BABAR detector at the PEP-II storage ring at SLAC. We measure the branching fraction for the decay B0bar --> Lambda_c^+ anti-Lambda K- to be (3.8 pm 0.8_{stat} pm 0.2_{sys} pm 1.0_{Lambda_c^+})x10^{-5}. The uncertainties are statistical, systematic, and due to the uncertainty in the Lambda_c^+ branching fraction. We find that the Lambda_c^+ K^- invariant mass distribution shows an enhancement above 3.5 GeV/c^2.
Self similar 3D distributions of point-particles, with a given quasifractal dimension D, were generated on a Menger sponge model and then compared with textit{2dfGRS} and textit{Virgo project} data footnote{http://www.mso.anu.edu.au/2dFGRS/, http://www.mpa-garching.mpg.de/Virgo/}. Using the principle of local knowledge, it is argued that in a finite volume of space only the two-point minus estimator is acceptable in the correlation analysis of self similar spatial distributions. In this sense, we have simplified the Pietronero-Labini correlative analysis by defining a K-minus estimator, which when applied to 2dfGRS data revealed the quasifractal dimension $Dapprox 2$ as expected. In our approach the K-minus estimator is used only locally. Dimensions between D = 1 and D = 1.7, as suggested by the standard $xi (r)$ analysis, were found to be fallacy of the method. In order to visualize spatial quasifractal objects, we created a small software program called textit{RoPo} (Rotate Points). This program illustrates and manifests local correlative analysis in which the visual inspection emerged as a first step and a key part of the method. Finally, we discuss importance and perspective of the visual inspection on available real and simulated distributions. It is also argued that results of contemporary cosmological simulations do not faithfully represent real data, as they show a formation of ever increasing collapsars. We consent that 2dfGRS data are reminiscent of some kind of underlying turbulence like effects in action.
The reaction e^+e^- ---> OMEGA+PI0 ---> PI+PI- 2PI0 has been studied with SND detector at VEPP-2M e^+e^- collider in the vicinity of the PHI(1020) meson resonance. The observed interference pattern in the energy dependence of the cross section is consistent with existence of the decay PHI ---> OMEGA+PI0 with a branching ratio of B(PHI ---> OMEGA+PI0)=(4.8+1.9-1.7+-0.8)x10^{-5}. The real and imaginary parts of the decay amplitude were measured. The PHI ---> OMEGA+PI0 decay was observed for the first time.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
