Search results for "MEG"
showing 10 items of 1641 documents
Hyperon polarization asymmetry: Polarized beams andΩ−production
1985
The parton recombination model relates polarizations in inclusive baryon fragmentation to those of the underlying constituent subprocesses. Measurements of spin-spin correlations in experiments using polarized beams will provide detailed information on the quark spin dynamics in the color-confining recombination process. We present a large number of predictions for the octet baryon\ensuremath{\rightarrow}octet baryon transitions. We discuss the production of polarized ${\ensuremath{\Omega}}^{\mathrm{\ensuremath{-}}}$'s, required to measure the magnetic moment of the ${\ensuremath{\Omega}}^{\mathrm{\ensuremath{-}}}$. We also review the data from unpolarized beam experiments, and find very sa…
Observation ofBMeson Decays tob1πandb1K
2007
We present the results of searches for decays of B mesons to final states with a b_1 meson and a charged pion or kaon. The data, collected with the BaBar detector at the Stanford Linear Accelerator Center, represent 382 million B-Bbar pairs produced in e+e- annihilation. The results for the branching fractions are, in units of 10^{-6}, B(B+ -> b1^0 pi+) = 6.7 +/- 1.7 +/- 1.0 (4.0 sigma), B(B+ -> b1^0 K+ = 9.1+/- 1.7+/- 1.0 (5.3 sigma), B(B0 -> b1^-/+ pi^+/-) = 10.9 +/- 1.2 +/- 0.9 (8.9 sigma), and B(B0 -> b1^-K+) = 7.4 +/- 1.0 +/- 1.0 (6.1 sigma), with the assumption that B(b_1 -> omega pi)=1. We also measure charge and flavor asymmetries Ach(B+ -> b1^0 pi+) = 0.05 +/- 0.16 +/- 0.02, Ach(B+…
Measurement of the Time-DependentCPAsymmetry inB0→DCP(*)h0Decays
2007
We report a measurement of the time-dependent CP-asymmetry parameters S and C in color-suppressed B-0 -> D((*)0)h(0) decays, where h(0) is a pi(0), eta, or omega meson, and the decays to one of the CP eigenstates K+K-, K-S(0)pi(0), or K-S(0)omega. The data sample consists of 383x10(6) Upsilon(4S)-> B (B) over bar decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The results are S=-0.56 +/- 0.23 +/- 0.05 and C=-0.23 +/- 0.16 +/- 0.04, where the first error is statistical and the second is systematic.
Antiproton-proton annihilation at rest into two-body final states
1993
We report measurements of branching ratios for production of a series of two meson final states in $$\bar p$$ p annihilations at rest in liquid hydrogen. We find: $$\begin{gathered} BR(\bar pp \to \pi ^ + \pi ^ - ) = (3.07 \pm 0.13) \cdot 10^{ - 3} \hfill \\ BR(\bar pp \to K^ + K^ - ) = (0.99 \pm 0.05) \cdot 10^{ - 3} \hfill \\ BR(\bar pp \to \pi ^0 \pi ^0 ) = (6.93 \pm 0.43) \cdot 10^{ - 4} \hfill \\ BR(\bar pp \to \pi ^0 \eta ) = (2.12 \pm 0.12) \cdot 10^{ - 4} \hfill \\ BR(\bar pp \to \pi ^0 \omega ) = (5.73 \pm 0.47) \cdot 10^{ - 3} \hfill \\ BR(\bar pp \to \pi ^0 \eta ') = (1.23 \pm 0.13) \cdot 10^{ - 4} \hfill \\ BR(\bar pp \to \eta \eta ) = (1.64 \pm 0.10) \cdot 10^{ - 4} \hfill \\ B…
A study of tau decays involving eta and omega mesons
1997
The 132 pb(-1) of data collected by ALEPH from 1991 to 1994 have been used to analyze eta and omega production in 7 decays. The following branching fractions have been measured: B(tau(-) --> nu(tau)omega h(-)) = (1.91 +/- 0.07 +/- 0.06) x 10(-2), B(tau(-) --> nu(tau)omega h(-)pi(0)) = (4.3 +/- 0.6 +/- 0.5) x 10(-3), B(tau(-) --> nu(tau)eta K-) = (2.9(-1.2)(+1.3) +/- 0.7) x 10(-4), B(tau(-) --> nu(tau)eta(h)(-)pi(0)) = (1.8 +/- 0.4 +/- 0.2) x 10(-3) and the 95% C.L. limit B(tau(-) --> nu(tau)eta pi(-)) < 6.2 x 10(-4) has been obtained. The omega pi(-) and eta pi(-)pi(0) rates and dynamics are found in agreement with the predictions made from e(+)e(-) annihilation data with the help of isospi…
Model-Independent Determination of the Spin of the Ω− and Its Polarization Alignment in ψ(3686)→Ω−Ω¯+
2021
We present an analysis of the process $\psi(3686) \to \Omega^- \bar{\Omega}^+$ ($\Omega^-\to K^-\Lambda$, $\bar{\Omega}^+\to K^+\bar{\Lambda}$, $\Lambda\to p\pi^-$, $\bar{\Lambda}\to \bar{p}\pi^+$) based on a data set of $448\times 10^6$ $\psi(3686)$ decays collected with the BESIII detector at the BEPCII electron-positron collider. The helicity amplitudes for the process $\psi(3686) \to \Omega^- \bar{\Omega}^+$ and the decay parameters of the subsequent decay $\Omega^-\to K^-\Lambda$ $(\bar{\Omega}^+\to K^+\bar{\Lambda})$ are measured for the first time by a fit to the angular distribution of the complete decay chain. The branching fraction of $\psi(3686) \to \Omega^- \bar{\Omega}^+$ is me…
Search for Heavy Particles Decaying into Electron-Positron Pairs inpp¯Collisions
2001
We present results of searches for technirho (rho (T)), techniomega (omega (T)), and Z' particles, using the decay channels rho (T), omega (T), Z' --> e(+)e(-). The search is based on 124.8 pb(-1) of data collected by the DO detector at the Fermilab Tevatron during 1992-1996. In the absence of a signal, we set 95% C.L. upper limits on the cross sections for the processes p (p) over bar --> rho (T), omega (T), Z' - e(+)e(-) as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate rho (T) and omega (T) states with masses below about 200 GeV. We exclude a Z' with mass below 670 GeV, assuming that it has the same couplings to fermi…
Photoproduction of thef2′(1525), a2(1320), andK2*(1430)
2016
Assuming that the ${f}_{2}^{\ensuremath{'}}(1525), {a}_{2}(1320)$, and ${K}_{2}^{*}(1430)$ resonances are dynamically generated states from vector-meson--vector-meson interactions in the $s$-wave with spin $S=2$, we study the $\ensuremath{\gamma}p\ensuremath{\rightarrow}{f}_{2}^{\ensuremath{'}}(1525)p, \ensuremath{\gamma}p\ensuremath{\rightarrow}{a}_{2}^{0}(1320)p$, and $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}_{2}^{*}(1430)\mathrm{\ensuremath{\Lambda}}(\mathrm{\ensuremath{\Sigma}})$ reactions. These reactions proceed in the following way: the incoming photon first mutates into a ${\ensuremath{\rho}}^{0}, \ensuremath{\omega}$, or $\ensuremath{\phi}$ meson via vector-meson dominance, …
Scale setting via the \Omega\ baryon mass
2011
We present the first results of an ongoing effort to determine the lattice scale on the N_f=2 CLS lattice ensembles via the mass of the \Omega\ baryon. Results from different methods are compared, and various sources of systematic uncertainty are discussed.
Observed ωb spectrum and meson-baryon molecular states
2020
We observe that four peaks seen in the high energy part of the $\Omega_b$ spectrum of the recent LHCb experiment are in remarkable agreement with predictions made for molecular $\Omega_b$ states stemming from the meson-baryon interaction, with an approach that applied to the $\Omega_c$ states gave rise to three states in good agreement with experiment in masses and widths. While the statistical significance of the peaks prevents us from claims of states at the present time, the agreement found should be an incentive to look at this experiment with increased statistics to give an answer to this suggestive idea.