Related papers: Exotic hadronic states at HERA
A search for anomalous single-top production, ep -> etX, t -> Wb, has been made with the ZEUS detector at HERA using an integrated luminosity of 130 pb^-1. No evidence for top-quark production was found in either the leptonic or the…
It has been ten years since the first report for a positive strangeness pentaquark-like baryon state. However the existence of the pentaquark state is still controversial. Some contradictions between the experiments are unsolved. In this…
Charm production in deep inelastic scattering has been measured with the ZEUS detector at HERA using an integrated luminosity of 120 pb^{-1}. The hadronic decay channels D^{+} -> K^{0}_{S} pi^{+}, Lambda_{c}^{+} -> p K^{0}_{S} and…
The hadron production in relativistic heavy ion collisions is well described by the quark combination model. The mixed ratios for various hadrons and the transverse momentum spectra for long-life hadrons are predicted and agree with recent…
In this paper the masses and decay processes of several new strange, charmed and bottomed exotic pentaquarks are predicted. Multiquarks are studied microscopically in a standard quark model. In pure ground-state pentaquarks the short-range…
We study the weak decay of the $\Lambda_b$ baryon into $J/\psi\ \phi\ \Lambda$, a process that is particularly well suited to analyze the physics of some of the recently observed or theoretically predicted exotic hadrons, as one expects to…
Events with isolated leptons and missing transverse momentum are searched for in electron- or positron-proton collisions at HERA by the H1 and ZEUS experiments. Such events may be explained within the Standard Model by W boson production,…
We examine the stop production scenario for the anomalous excess of high $Q^2$ events observed at HERA, by taking into account the constraints coming from the leptoquark search at Tevatron and the atomic parity violation experiments. This…
We review the current status of the exotic pentaquark baryons. After a brief look at experiments of both positive and negative results, we discuss theoretical methods to study the structure and reactions for the pentaquarks. First we…
We study the Theta+(1540) discovered at SPring-8. We apply Quark Model techniques, that explain with success the repulsive hard core of nucleon-nucleon and kaon-nucleon exotic scattering, and the short range attraction present in…
Results on QCD studies from the H1 and ZEUS Collaborations at the ep collider HERA are presented and their impact on LHC physics discussed.
An overview of recent measurements of charm and beauty production in ep collisions at HERA is presented. Various techniques are used by the ZEUS and H1 collaborations to efficiently tag heavy quarks in events and different regions of phase…
We search for the strange pentaquark $\Theta^+$ using kaon interactions in the material of the Belle detector. No signal is observed in the $p K_S$ final state, while in the $p K^-$ final state we observe $\sim 1.6 \cdot 10^4$…
The quark model does not exclude states composed of more than three quarks, like pentaquark systems. Controversial evidence for such states has been published in the last years, in particular: for a strange pentaquark Theta(1540)+; for a…
We investigate the semi-inclusive production of hidden-charm exotic states, including $X(3872)$, $Z_c$, $Z_{cs}$ and the pentaquark $P_c$ states, in lepton-proton scattering processes. These hadrons are close to the thresholds of a pair of…
A new mechanism of the production of hypothetical $\Theta(ud\bar{s}ud)^+$ pentaquark state is suggested. The considered mechanism is based on the exchange by exotic Regge trajectories in the $t$ channel. It is shown that the momentum…
Dibaryons provide insight into the strong interaction beyond conventional hadrons. Strange dibaryons, containing strange quarks, are especially valuable for probing hyperon-nucleon (YN) and hyperon-hyperon (YY) interactions. We report…
We review the experimental evidence on firstly, strangeness production as a signature for the QCD phase transition and secondly, pentaquarks, the latest and most exotic manifestations of strangeness in hadrons.
Recent results on the search for pentaquarks and on charmonium spectroscopy at BaBar are reviewed. The latter includes the observation of the puzzling new state X(3872) -> J/psi pi+ pi- in B decays, and the searches for X(3872) in two-body…
I introduce an entirely new dynamical description for exotic charmoniumlike hadrons, based upon the competing effects of the strong attraction between quarks in a diquark, and the inability of the diquark to hadronize on its own due to…