Related papers: New structures in the proton-antiproton system
The main dynamical mechanisms of the reaction $\pi^-p \rightarrow a^0_0 (980)n \rightarrow \pi^0\eta n$ at high energies, currently investigated at Serpukhov and Brookhaven, are considered in detail. It is shown that the observed forward…
We present a review of recent results from BaBar experiment. BaBar detector has collected about 256 millions of $B\bar B$ events at PEP-II, the asymmetric $e^+e^-$ collider located at SLAC running at the $\Upsilon(4S)$ resonance. We have…
The COSY-11 collaboration measured the pp -> ppeta and pp -> ppeta' reactions in order to perform comparative studies of the interactions within the proton-proton-meson system. This thesis presents in detail the analysis of the pp -> ppeta'…
Using data samples collected at center-of-mass energies between 2.000 and 3.080 GeV with the BESIII detector operating at the BEPCII collider, a partial-wave analysis is performed on the process $e^+e^-\to\eta\pi^+\pi^-$. In addition to the…
It is recalled that spin-observables in the strangeness-exchange reaction $\bar{p}{p} \to \bar{\Lambda}{\Lambda}$ are not independent but are related to each other by simple algebraic relations. This provides constraints on the existing…
A new measurement of the b-bbar production cross section in 920 GeV proton-nucleus collisions is presented by the HERA-B collaboration. The b-bbar production is tagged via inclusive bottom quark decays into J/psi mesons, by exploiting the…
We report observation of a narrow peak structure at ~1.54 GeV with a Gaussian width sigma=6 MeV in the missing of K_s in the reaction gamma+p = pK_sK_L. The observed structure may be due to the interference between a strange (or…
In the reaction of the antiproton-deuteron electromagnetic annihilation pbar + d --> e+e-n the value of the invariant mass M of the (e+e-) pair can be near or below the (pbar p) mass even for enough high momentum of incident antiproton.…
Exclusive measurements of the production of eta mesons in the p+p->p+p+eta reaction have been carried out at excess energies of 16 and 37 MeV above threshold. The deviations from phase space are dominated by the proton-proton final state…
Photoproduction of $\pi\eta$-pairs from nucleons has been investigated from threshold up to incident photon energies of $\approx$~1.4~GeV. The quasi-free reactions $\gamma p\rightarrow p\pi^0\eta$, $\gamma n\rightarrow n\pi^0\eta$, $\gamma…
The sensitivity of $W$ and $Z$ production at RHIC to the possible $\bar u/\bar d$ asymmetry in the proton is studied. The ratios of the $W^+$ over $W^-$ production cross sections in $p + p$ collision, as well as the ratios of the $W^+$ and…
A new parameterization of the antiproton inclusive production cross section in proton-proton and proton-nucleus collisions is proposed. A sample of consistent pA->pbar X$ experimental data sets measured on 1<A<208 nuclei, from 12 GeV up to…
We review recent experimental and theoretical developments in the study of the sea quark structure of the proton. In the light quark sector, we analyse the recent pp and pD Drell-Yan data from the E866/NuSea experiment at Fermilab, and…
The nucleon-like member $N(1685)$ of the speculative baryon antidecuplet denotes one possible explanation for the narrow peak-structure around $W = 1.68$ GeV observed in the total cross section of $\eta$-photoproduction off the neutron. If…
Using 2917 $\rm{pb}^{-1}$ of data accumulated at 3.773~$\rm{GeV}$, 44.5~$\rm{pb}^{-1}$ of data accumulated at 3.65~$\rm{GeV}$ and data accumulated during a $\psi(3770)$ line-shape scan with the BESIII detector, the reaction…
The continuum structure of the unbound system $^{10}$Li, inferred from the $^{9}$Li$(d,p)^{10}$Li transfer reaction, is reexamined. Experimental data for this reaction, measured at two different energies, are analyzed with the same reaction…
The analysis of the data on the reactions $^4$Hep -> pppnn and $^4$Hep -> dppn obtained at the 2-m ITEP liquid-hydrogen bubble chamber exposed to beams of $^4$He nuclei with momenta of 2.7 and 5 GeV/c revealed a narrow structures in the…
A theoretical study of $\bar{p}p \to \bar{p}n \pi^+ $ reaction for anti-proton beam energy from 1 to 4 GeV is made by including contributions from various known $N^*$ and $\Delta^*$ resonances. It is found that for the beam energy around…
The significant excess of events recently found by the H1 and ZEUS Collaborations at HERA in the deep-inelastic e^+ p scattering for high momentum-transfers squared Q^2>15000 GeV^2 over the expectation of the standard model can be explained…
pi-N and pi-pi interactions near threshold are uniquely sensitive to the chiral symmetry breaking part of the strong interaction. The pi-N sigma-term value with its implications for nucleon quark structure and the recent controversy…