Related papers: Two photon width of eta_c
Magnetic- and electric-dipole two-photon absorption (MED-TPA), recently introduced as a new spectroscopic technique for studying transitions between states of opposite parities, is investigated from a theoretical point of view. A new…
We estimate the decay rates of $\eta_c\rightarrow 2\gamma$, $\eta_c'\rightarrow 2\gamma$, and $J/\psi\rightarrow e^+ e^-$, $\psi^\prime\rightarrow e^+e^-$, by taking into account both relativistic and QCD radiative corrections. The decay…
It is suggested that the recently reported charged charmoniumlike resonance $Z_c(4100)$ and the previously observed $Z_c(4200)$ are two states of hadrocharmonium, related by the charm quark spin symmetry in the same way as the lowest…
We discuss the internal structure of radially excited charmonium mesons based on the equal-time and Coulomb gauge Bethe-Salpeter (BS) amplitudes, which are obtained in lattice QCD. Our simulations are performed with a relativistic…
We present an effective field theory based extraction of the eta_c mass and width from a recent measurement by CLEO of the photon line shape in J/Psi -> eta_c gamma decay.
Charmonium spectroscopy with Kogut-Susskind valence quarks are carried out for quenched QCD at $\beta=6.0$ and for two-flavor full QCD at $\beta=5.7$. Results for 1P--1S mass splitting and estimates of $\alpha^{(5)}_{\overline{MS}}(m_Z)$…
We present a calculation of the two-photon and two-gluon widths for the equal mass quarkonium states $^1S_0$, $^3P_0$ and $^3P_2$ of the charmonium and upsilon systems. The approach taken is based on using the full relativistic…
We investigate the spectroscopy and decays of the charmonium and upsilon systems in a potential model consisting of a relativistic kinetic energy term, a linear confining term including its scalar and vector relativistic corrections and the…
In this work we give a comprehensive derivation of an exact and numerically feasible method to perform ab-initio calculations of quantum particles interacting with a quantized electromagnetic field. We present a hierachy of…
In this work, we estimate the mass spectra and decay properties of charmonium ($c \bar c$) using a non-relativistic potential model. We employ a potential model incorporating a Coulomb like term, representing one gluon exchange at short…
We consider QED in five dimensions in a configuration where matter is localized on a 3-brane while foton propagates in the bulk. The idea is to investigate the effects of the Kaluza-Klein modes of the photon in the relativistic regime, but…
The amplitudes for photoproduction of two pseudoscalars on a nucleon are expanded in the overall c.m. frame in a model independent way with respect to the contribution of the final state partial wave of total angular momentum $J$ and its…
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 investigate equilibrium and non-equilibrium charge-transfer processes by performing high-resolution transport spectroscopy. Using electrostatically defined quantum dots for energy-selective emission and detection, we achieved…
Using exact diagonalzation techniques, we study a model of interacting electrons and phonons. The spectral width of the phonons is found to be reduced as the Coulomb interaction U is increased. For a system with two modes per site, we find…
We describe and demonstrate a quantum state tomography for measuring the complex temporal waveform of narrowband biphotons. Through six sets of two-photon interference measurements projected in different polarization subspaces, we can…
For the family of model soft Coulomb potentials represented by V(r) = -\frac{Z}{(r^q+\beta^q)^{\frac{1}{q}}}, with the parameters Z>0, \beta>0, q \ge 1, it is shown analytically that the potentials and eigenvalues, E_{\nu\ell}, are…
In this short review we present and discuss all the experimental information about the charged exotic charmonium states, which have been observed over the last five years. We try to understand their properties such as masses and decay…
The aim of this review paper is to enlighten some recent progresses in quantum optical metrology in the part of quantum efficiency measurements of photo-detectors performed with bi-photon states. The intrinsic correlated nature of entangled…
The relativity of simultaneity together with definition of a quantum state's collapse result into experimental situations, where a multiple measurements can be taken on an uncollapsed quantum state. A quantum state's collapse space-time…