Evidence For Narrow Resonance Research Articles

A Novel Population of Slow Magnetosonic Waves and a Method for the Observation of the Roots of Plasma Bubbles in the Lower Ionosphere

AbstractUsing data from the Van Allen Probe and Swarm‐Bravo satellites, evidence for a persistent population of slow magnetosonic waves in the ionosphere is presented. Dispersion relations from two‐fluid analyses of waves in warm plasma are used to interpret and explicate these observations. These waves appear to be continuously present and globally distributed. Their amplitudes systematically decrease with increasing altitude. The amplitudes are also correlated with longitude in a manner consistent with the global distribution of lightning strikes. Evidence for narrow resonances in the Swarm data consistent with doppler shifted Schumann resonance frequencies is presented. In addition, nearly dispersionless fast magnetosonic waves are sometimes also seen. A new method for the analysis of these waves suggests they show the existence of “foamy” plasma bubble “roots” at the base of the ionosphere.

Pentaquark Searches at CDF

Recently there has been revival of interest in exotic baryon spectroscopy triggered by experimental evidence for pentaquarks containing u,d,s and c-quarks. We report results of the searches for pentaquark states in decays to p K0S, Xi- pi+,- and D*- p performed at CDF detector using 220 pb-1 sample of pp= interactions at sqrt(s) of 1.96 TeV. No evidence for narrow resonances were found in either mode.

Searches for pentaquarks at CDF

Recently there has been revival of interest in exotic baryon spectroscopy triggered by experimental evidence for pentaquarks containing u, d, s and c-quarks. We report results of the searches for pentaquark states in decays Θ−π± and D*−p, D−p and D̄0p performed at CDF detector using 220 pb−1 sample of pp̄ interactions at √s of 1.96 TeV. No evidence for narrow resonances were found in either mode.

Results from $$\bar pp \to \phi \phi $$

The reaction\(\bar pp \to \phi \phi \) is investigated in the JETSET (PS202) experiment using an internal target in LEAR. Data have been analysed at a variety of beam momenta from 1.2 GeV/c to 2.0 GeV/c, corresponding to centre-of-mass energies between 2.15 GeV and 2.43 GeV. A strong φφ-signal was observed over the whole, energy range, preliminary results giving φφ-yields of (1–2) μb. No evidence for narrow resonances was found within the accumulated statistics. The capability of the experiment to measure φ→K+K− decay angular distributions and thus put constraints on the spin-parity quantum numbers of a possible resonant intermediate state is demonstrated.

Search for Quark Effects in thed+He4System

It has been suggested that bags containing more than three interacting quarks may be formed in high-energy collisions; these states would appear as narrow resonances in the inelastic channels. We have measured the inclusive cross section $d+^{4}\mathrm{He}\ensuremath{\rightarrow}p+X$ at ${E}_{\mathrm{c}.\mathrm{m}.}=6.25 \mathrm{to} 7.91$ GeV in steps of 50 to 100 MeV to search for an eighteen-quark bag resonance. No evidence for narrow resonances was found and upper limits on the production cross section are presented.

Evidence for a narrow resonance at 10.01 GeV in electron-positron annihilations

We observe evidence for a secon narrow resonance in the reation e +e − → hadrons at √s around 10 GeV using the DASP detector at the DORIS storage ring. The mass of the resonance is (10.01 ± 0.02) GeV; its width is in agreement with the storage ring resolution of ≈ 9 MeV. From the integrated cross section, an electronic width of Λ ee = (0.35 ± 0.14) KeV is derived.

Limits on Charmed-Particle Production in Proton-Nucleus Collisions at 400 GeV/c

We have searched for the charmed and other new particles by measuring the hadron pair mass spectra in proton-nucleus collisions at 400 GeV/c. Results are presented for ${\ensuremath{\pi}}^{\ensuremath{-}}{K}^{+}$, ${\ensuremath{\pi}}^{+}{K}^{\ensuremath{-}}$, and ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ pairs in the mass region from 1.5 to 4.0 ${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c}}^{2}$. No evidence for narrow resonances was found. The sensitivity of the search varied from 2 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}30}$ ${\mathrm{cm}}^{2}$ at 2 ${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c}}^{2}$ to 5 \ifmmode\times\else\texttimes\fi{} ${10}^{\ensuremath{-}32}$ ${\mathrm{cm}}^{2}$ at 4 ${\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c}}^{2}$. Experimental checks were provided by the observation of a clean $\frac{J}{\ensuremath{\psi}(3.1)}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$ signal.

The reaction K +d→K +π+π−d at 4.6 GeV/ c

In an experiment with the CERN 2 metre bubble chamber, the reaction K +d→K + π + π −d has been studied at an incident K + momentum of 4.6 GeV/c. The cross section is 250±30 μb. A strong K ∗ (892) signal is seen and also a broad enhancement in the Q region ( M(K ππ) < 1.5 GeV) with no evidence for narrow resonances in this mass interval. The production and decay properties of these objects are studied, and comparisons made with similar reactions on protons. The properties of the angular distributions of the Q decay are very similar to those found in the related reaction on a proton target. The spin-parity of the Q system is found to be predominantly 1 + although 2 − cannot be excluded. The dπ mass distributions show an enhancement for mass values ∼2.2 GeV; however the marked asymmetry in the corresponding decay angular distribution argues against a resonance interpretation of this effect.