相关论文: The electromagnetic form factors of $\Lambda$ hype…
We analyse various $U(1)_{EM}$ form factors of mesons at strong coupling in an $\mathcal{N}=2$ flavored version of $\mathcal{N}=4$ $SYM$ which becomes conformal in the UV. The quark mass breaks the conformal symmetry in the IR and generates…
Using a data sample of $e^{+}e^{-}$ collision data corresponding to an integrated luminosity of 20.3 fb$^{-1}$ collected by the BESIII detector at the BEPCII collider, we present an observation of transverse polarization and a complete…
The simultaneous investigation of the pion electromagnetic form factor in the space- and time-like regions within a light-front model allows one to address the issue of non-valence components of the pion and photon wave functions. Our…
Recently, the BESIII experiment renewed the interest on baryon form factors by measuring the modulus and phase of the ratio $G_E^\Lambda/G_M^\Lambda$ between the electric and the magnetic $\Lambda$ form factors with unprecedented accuracy.…
A microscopic model of the electromagnetic form factor of the nucleon is developed in a hadronic framework, including pions, nucleons and the Delta-resonance explicitly. The space like on-shell form factors are reproduced and predictions…
Cross-section distributions are calculated for the reaction $e^+ e^- \rightarrow J/\psi\rightarrow \bar{\Lambda}(\rightarrow \bar{p}\pi^+) \Lambda(\rightarrow p\pi^-)$, and related annihilation reactions mediated by vector mesons. The…
Electric dipole moment (EDM) of baryons provides a sensitive probe of CP-violating interactions beyond the Standard Model. Motivated by the recent BESIII measurement on the $\Lambda$-hyperon EDM [1], we present the first perturbative QCD…
We present the first measurements of the electric and magnetic form factors of the neutron in the time-like (positive $q^2$) region as function of four-momentum transfer. We explored the differential cross sections of the reaction $e^+e^-…
The three electromagnetic form factors for the transition from a 3/2+ Sigma* hyperon to the ground-state Lambda hyperon are studied. At low energies, combinations of the transition form factors can be deduced from Dalitz decays of the…
We compute electromagnetic and two-photon transition form factors of ground-state pseudoscalar mesons: $\pi,\,K,\,\eta_c,\,\eta_b$. To this end, we employ an algebraic model based upon the coupled formalism of Schwinger-Dyson and…
We discuss the pion and nucleon form factors and generalized form factors within the large-Nc approach in the space-like region. We estimate their theoretical uncertainties through the use of the half-width rule, amounting to taking the…
The vector dominance of the electromagnetic form factors both for mesons and baryons arises naturally in holographic QCD, where both the number of colors and the 't Hooft coupling are taken to be very large, offering a bona-fide derivation…
Elastic electromagnetic form factors of nucleons are investigated both for the time-like and the space-like momentums by using the unsubtracted dispersion relation with QCD constraints. It is shown that the calculated form factors reproduce…
We present a simultaneous analysis of elastic and transition form factors of the nucleon. The calculations are performed in the framework of an algebraic model of baryons. Effects of meson cloud couplings are considered.
Nucleon elastic and transition form factors are analyzed in the framework of a collective model of baryons. Effects of meson cloud couplings and relativistic corrections are considered.
The electromagnetic (EM) form fators of the pseudoscalar and vector mesons are calculated in the light-front framework. We extract these form factors from the relevant matrix elements directly, instead of choosing the Breit frame. The…
New, accurate measurements of the pion and kaon electromagnetic form factors are expected in the near future from experiments at electron-positron colliders,using the radiative return method. We construct a model for the timelike pion…
In Ultra Relativistic Heavy-Ion Collisions (URHIC's) the light vector mesons play a crucial role in the description of hadronic interactions in a non-pertrubative QCD region. In this region efective hadron models use composite hadrons and…
Elastic electromagnetic form factors of nucleons are investigated both for the time-like and the space-like momentums under the condition that the QCD constraints are satisfied asymptotically. The unsubtracted dispersion relation with the…
The internal structure of the resonant Lambda(1405) state is investigated based on meson-baryon coupled-channels chiral dynamics, by evaluating density distributions obtained from the form factors of the Lambda(1405) state. The form factors…