Related papers: Hadron Spectroscopy in electrons-protons Collision…
Recent results from H1, ZEUS, HERMES and HERA-B on searches for exotic baryons in ep collisions, eD scattering and pA scattering at HERA are reviewed. Evidence for the production of the strange pentaquark Theta^+ and of a narrow…
Recent spectroscopy studies performed in high energy ep collisions by the H1 and ZEUS Collaborations are described. The status of the searches for the strange pentaquark, the Theta+, is presented as well as results on searches for further…
Recent results on spectroscopy with special focus on searches for pentaquarks are presented from the H1 and ZEUS collaborations. Cross sections of observed states and upper limits on the production cross section of unobserved states are…
Recent strong experimental evidence of a narrow exotic S = +1 baryon resonance, $\Theta^+$, suggests the existence of other exotic baryons. We discuss the prospects of confirming earlier experimental evidence of $\Theta^+$ and the…
Recent results on searches for new particles at the electron-proton collider HERA are reported. Based on roughly 100pb-1 of e^+p data and 16pb-1 of e^-p data per experiment, taken in the years 1994-2000, the H1 and ZEUS collaborations have…
Light and charmed hadrons are produced copiously in ep collisions with a centre-of-mass energy of 318 GeV at HERA. Results of the ZEUS Collaboration on pentaquark searches, deuteron and antideuteron production and charmed-meson…
Recent results on charm fragmentation and hadron spectroscopy in $e^+/e^- p$ collisions at HERA with the ZEUS and H1 detectors are presented. The measured fragmentation ratios and fragmentation fractions are in agreement with those measured…
Recent results on searches for new particles at the electron-proton collider HERA are reported. Based on roughly 40pb-1 of e^+p data taken in the years 1994-1997, the H1 and ZEUS collaborations have derived new exclusion limits for the…
An overview of the recent results on strangeness production and spectroscopy from the electron-proton collider experiments H1 and ZEUS at HERA is presented. Production of particles with light and strange quarks is discussed and compared…
A resonance search has been made in the D^*+/- p^-/+ invariant-mass spectrum with the ZEUS detector at HERA using an integrated luminosity of 126 pb^-1. The decay channels D^*+ -> D^0 pi^+_s -> (K^- pi^+) pi^+_s and D^*+ -> D^0 pi^+_s ->…
Recent results from searches for physics beyond the Standard Model (SM) in electron/positron-proton collisions at HERA at center-of-mass energies of 300 and 320 GeV are presented. They were performed on a data sample collected in the period…
The three pentaquark candidates Theta^+(1530), Xi(1862) and Theta^0_c(3100) have been studied in ep collisions at a centre-of-mass energy sqrt{s}=300-318 GeV using the full luminosity of the HERA-I data. Searches for narrow baryonic states…
We report on the progress of the pentaquark searches by the STAR collaboration in p+p, d+Au, and Au+Au at $s_{NN}=\sqrt{200}$ GeV collisions through one of the decay modes of $\Theta^{+}\to p+K_{s}^{0}$. $\Theta^{+}$ state is an exotic…
Recent results on open charm production at HERA are presented. Charm quarks are identified via the reconstruction of D-mesons. The charm contribution to the proton structure function is shown. Evidence for an exotic anti-charmed baryon…
Various searches for leptoquarks, scalar quarks in $R_p$-violating supersymmetric models, and excited fermions performed by the HERA experiments H1 and ZEUS are reviewed. No evidence for new particle production was observed from data…
The data on hadron--nucleus collisions at 400--700 GeV, collected by the SELEX experiment at Fermilab, are analyzed for formation of the exotic pentaquark baryon $\Theta^+(1540)$. A narrow enhancement near 1539 MeV is observed in the mass…
Recent results on light hadron spectroscopy are reported, with special emphasis on the evidence for a narrow baryonic state decaying to Ks p and Ks pbar, compatible with the pentaquark state theta^+ observed by fixed target experiments. The…
Inclusive photoproduction cross-sections of the neutral mesons eta, rho^0, f_0(980) and f_2(1270) have been measured by H1 and compared to the photoproduction of pi^+ in ep collisions at HERA. Also, inclusive KsKs production and evidence…
The early observation at HERA of an excess of events compared to the expectation from the Standard Model in very short distance $e^+p$ deep-inelastic scattering processes has renewed the interest in the search for new physics which could…
The earlier search at HERMES for narrow baryon states excited in quasi-real photoproduction, decaying through the channel $pK_S^0\rightarrow p\pi^+\pi^-$, has been extended with improved decay-particle reconstruction, more advanced particle…