相关论文: Have Gluonic Excitations Been Found?

A search for pair-produced charged Higgs bosons is performed with the L3 detector at LEP using data collected at a centre-of-mass energy of 188.6 GeV, corresponding to an integrated luminosity of 176.4 pb^-1. Higgs decays into a charm and a…

The near threshold photo or electroproduction of heavy vector quarkonium off the proton is studied in quantum chromodynamics. Similar to the high-energy limit, the production amplitude can be factorized in terms of gluonic Generalized…

We study the possible exotic states with $J^{PC} = 0^{+-}$ using the tetraquark interpolating currents with the QCD sum rule approach. The extracted masses are around 4.85 GeV for the charmonium-like states and 11.25 GeV for the…

We study the dynamics in phases with vector condensates of gluons (gluonic phases) in dense two-flavor quark matter. These phases yield an example of dynamics in which the Higgs mechanism is provided by condensates of gauge (or gauge plus…

We analyze the potential of the CERN Large Hadron Collider (LHC) to search for excited spin-1/2 electrons and neutrinos. Assuming a SU(2)_L X U(1)_Y invariant model, we study in detail the single production of excited electrons and…

We review recent progress in the investigation of the electroexcitation of nucleon resonances, both in experiment and in theory. The most accurate results have been obtained for the electroexcitation amplitudes of the four lowest excited…

A long-lived $J^{\pi}=4_1^+$ isomer, $T_{1/2}=2.2(1)$ms, has been discovered at 643.4(1) keV in the weakly-bound $^{26}_{9}$F nucleus. It was populated at GANIL in the fragmentation of a $^{36}$S beam. It decays by an internal transition to…

The $J/\Psi$ photo-production reactions on the nucleon can provide information on the roles of gluons in determining the $J/\Psi$-nucleon ($J/\Psi$-N) interactions and the structure of the nucleon. The information on the $J/\Psi$-N…

The nuclear enhancement observed in inelastic photoproduction of $J/\Psi$ should not be interpreted as evidence for an increased gluon density in nuclei. The nuclear suppression of the production rate due to initial and final state…

We extend previous calculations of leading-order correlation functions of spin-0 and spin-1 light quarkonium hybrids to include QCD condensates of dimensions five and six, with a view to improving the stability of QCD sum-rules analyses in…

In this paper, a new type of hybrid state, which consists of two valence quarks and two valence antiquarks together with a valence gluon, the gluonic tetraquark states, are investigated. Twenty-four currents of the the gluonic hidden-charm…

Details of the analysis of the eta pi- system studied in the reaction pi^{-} p --> eta pi^{-} p at 18 GeV/c are given. Separate analyses for the 2 gamma and pi+ pi- pi0 decay modes of the eta are presented. An amplitude analysis of the data…

The $\pi_1(1600)$, a $J^{PC} = 1^{-+}$ exotic meson has been observed by experiments using pion beams. Theorists predict that photon beams could produce gluonic hybrid mesons, of which the $\pi_1(1600)$ is a candidate, at enhanced levels…

The yield of the isomeric state 117mSn (Eiso = 314.58 keV) has been measured in (gamma, gamma') reaction by activation method with the bremsstrahlung end-point energy from 2.1 to 3.0 MeV. Only one intermediate state (IS) responsible for the…

Relying on the collinear factorization approach, we demonstrate that H1 and ZEUS measurements of exclusive light vector meson and photon electroproduction cross sections can be simultaneously described for photon virtualities of $Q >2 GeV$.…

A search for excited lepton production in e+e- collisions was performed using the data collected by the DELPHI detector at LEP at centre-of-mass energies ranging from 189 GeV to 209 GeV, corresponding to an integrated luminosity of…

We present results from a lattice QCD study of nucleon matrix elements at vanishing momentum transfer for local and twist-2 isovector operator insertions. Computations are performed on gauge ensembles with non-perturbatively improved…

At high energy, exclusive meson photo- and electro-production give access to the structure of hadronic matter. At low momentum transfers, the exchange of a few Regge trajectories leads to a comprehensive account of the cross-sections. Among…

This contribution is a brief review of the status of hybrid baryons, which are hypothetical baryons that incorporate a gluonic excitation. We first summarize the status of hybrid mesons, since this closely related topic has seen…

Searches in ep collisions for heavy excited fermions have been performed with the ZEUS detector at HERA. Excited states of electrons and quarks have been searched for in e^+p collisions at a centre-of-mass energy of 300 GeV using an…