CHARM PRODUCTION IN ep INTERACTIONS AT HERA and EVIDENCE FOR A NARROW ANTI-CHARMED BARYON STATE AT H1
نویسنده
چکیده
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 state observed by H1 is presented. The data show a narrow resonance in the Dp invariant mass combination at 3099±3stat±5syst MeV. The resonance is interpreted as an anti-charmed baryon with minimal constituent quark content uuddc̄ together with its charge conjugate. Such a signal is not observed in a similar preliminary ZEUS analysis.
منابع مشابه
The charm contribution into the proton structure function in DIS at the HERA ep - collider
The charm contribution into the proton structure function in DIS at the HERA ep-collider Abstract In the framework of perturbative QCD and a model for the production of charmed hadrons the structure function F c 2 is calculated and compared with the experimental data of H1 and ZEUS Collaborations. We show that the spectator mechanism of the D *-meson production independent of a hadronic remnant...
متن کاملSpectroscopic Measurements Using the H1 and Zeus Detectors
At the ep-collider HERA, interactions are studied at a centre-of-mass energy of 300–320 GeV by the H1 and ZEUS multi-purpose detectors. The virtuality, Q, of the exchanged photon allows to distinguish two kinematical regimes: photoproduction (Q < 1GeV) and deep-inelasticscattering (DIS) (Q > 1GeV). As recent results from fixed-target experiments have evidence for a narrow baryon resonance decay...
متن کاملCharmed Meson Production Deep Inelastic Scattering at HERA and Extraction of F cc
Recent results from the H1 and ZEUS collaborations on charmed meson production in deep in-elastic ep scattering at HERA are presented. Single differential cross sections of D * ± , D ± and D 0 meson production are measured in the kinematic range 5 GeV 2 < Q 2 < 1000 GeV 2 and 0.02 < y < 0.7. Leading and next-to-leading order QCD predictions are compared to these measurements. The charm contribu...
متن کاملResonance Searches at HERA
Inclusive production of K SK 0 S in ep collisions was studied with the ZEUS detector. Significant production of J = 2 tensor mesons and of the 0 glueball candidate f0(1710) was seen. Masses and widths were compared with previous experiments. The H1 Collaboration saw a charm pentaquark candidate in the D∗p spectrum at 3.1 GeV, which was not confirmed by a ZEUS higher statistics search. With the ...
متن کاملDiffractive Final States with the H1 Detector at HERA
Abstract. Recent measurements of diffractive dijet and charm quark production in electron-proton collisions using the H1 detector at HERA are presented, where the exchanged photon is either almost real or highly virtual. The data are compared with leading and next-to-leading order QCD calculations based on the diffractive parton distributions obtained from a recent DGLAP QCD analysis of H1 incl...
متن کامل