282 research outputs found
Low Mass Exotic Baryons: Myth or Reality ?
Using mainly p p and p
p~p X reactions, narrow baryonic structures were observed in the
mass range 950 M 1800 MeV.Comment: 9 pages, 9 figures, 1 table, revtex, to be published in Proceedings
of the XVI International Baldin Seminar on High Energy Physics Problems,
Dubna 10-15 june 200
Further evidence for narrow exotic low mass baryons
Although narrow low mass baryonic structures, observed mainly in SPES3
(Saturne) data, were not confirmed in recent experiments using lepton probes,
their existence is confirmed in other data, where hadronic probes were used.Comment: 5 pages, 3 figure
Search for Low Mass Exotic mesonic structures. Part II: attempts to understand the experimental results
Our previous paper, part I of the same study, shows the different
experimental spectra used to conclude on the genuine existence of narrow,
weakly excited mesonic structures, having masses below and a little above the
pion (M=139.56 MeV) mass. This work \cite{previous} was instigated by the
observation, in the disintegration: pP,
P \cite{park}, of a narrow range of dimuon masses. The
authors conclude on the existence of a neutral intermediate state P, with
a mass M=214.3 MeV 0.5 MeV. We present here some attempts to understand
the possible nature of the structures observed in part I.Comment: 3 pages, 4 figures. Follows 0710.1796. Both replace arXiv:0707.1261
[nucl-ex
Further Evidence of Narrow Baryonic Structures with Hadronic as Well as Leptonic Probes
Although extracted from several experiments using hadronic probes
\cite{bor1}, narrow baryonic structures have been sometimes met with disbelief.
New signatures are presented, which appear from already published data,
obtained with hadronic probes as well as with leptonic probes. The authors of
these results did not take into account the possibility to associate the
discontinuities of their spectra with the topic of narrow baryonic low mass
structures. The stability of the observed narrow structure masses, represents a
confirmation of their genuine existence.Comment: 6 pages, 8 figures. Contribution XVII International Seminar on High
Energy Physics Problems, Relativistic Nuclear Physics and Quantum
Chromodynamics, Dubna, (Russia) Sept. 27- Oct 2, 200
Exotic low mass narrow baryons extracted from charge exchange reactions
This paper aims to give further evidence for the existence of low mass exotic
baryons. Narrow structures in baryonic missing mass or baryonic invariant mass
were observed during the last twelve years. Since their evidence is still under
debate, various data, measured with incident hadrons, by different
collaborations, are reanalyzed to bring evidence on these narrow exotic
baryonic resonances excited in charge-exchange reactions. These structures are
clearly exotic as there is no room for them in the configurations: their
width is smaller than the widths of "classical" baryonic resonances, moreover
some of the masses lie below the pion threshold mass.Comment: 21 pages, 27 figure
Are the exotic mesons and baryons, recently observed, a signature of quark-hadron duality?
Narrow low mass exotic hadronic structures were recently observed in mesons, baryons and dibaryons. Narrow mesons, in the mass range 300M750 MeV were observed using the ppppX reaction. Narrow baryons in the mass range 1000M1400 MeV were observed using the pppX and dpppX reactions. The statistical significances of these structures vary up to 4.6 standard deviations (S.D.) for mesons and up to 16.9 S.D. for baryons. These exotic states are associated with precursor quark deconfinement
\pi N and \eta p deexcitation channels of the N^* and \Delta baryonic resonances between 1470 and 1680 MeV
Two reactions, pp->ppX and pp->p\pi^+X, are used to study the 1.47<M<1.68 GeV
baryonic mass range. Three different final states are considered in the
invariant masses: N^* or \Delta^+, p\pi^0, and p\eta. The last two channels are
defined by software cuts applied to the missing mass of the first reaction.
Several narrow structures are extracted with widths \sigma(\Gamma) varying
between 3 and 9 MeV. Some structures are observed in one channel but not in
others. Such nonobservation may be due either to the spectrometer momenta
limits or to the physics (e.g. no such disintegration channel is allowed from
the narrow state considered).
We tentatively conclude that the broad Particle Data Group (PDG) baryonic
resonances N(1520)D13, N(1535)S11, Delta(1600)P33, and N(1675)D15 are
collective states built from several narrow and weakly excited resonances, each
having a (much) smaller width than the one reported by PDG.Comment: 29 pages, plus 50 (.png) figures Will be published in a slightly
reduced size in Phys. Rev.
Charge exchange reactions on baryons and exotic low-mass narrow baryons.
Narrow structures in baryonic missing mass or baryonic invariant mass were observed during the last ten years. Since their existence remains controversial, previously published data, measured with incident hadrons, are reanalyzed to add new pieces of information. This contribution gives further evidence to the existence of low mass exotic baryons, excited in charge-exchange reaction
- …