Related papers: The Froissart bound for inelastic cross-sections
In-medium chiral perturbation theory is used to calculate the density dependence of the quark condensate $<\bar qq>$. The corrections beyond the linear density approximation are obtained by differentiating the interaction contributions to…
The latest $\pi N$ elastic scattering data are re-analysed to determine the coupling constant $g_c$ of the charged pion, using the dispersion relation for the invariant amplitude $B^{(+)}$. Depending on the choice of data-base, values…
An azimuthal dependence of pions produced in polarized Deep Inelastic Scattering, gamma^* - p(transv. polarized) -> pion + X, has been recently observed and might be related to the so-called Collins effect. We discuss in details, for a…
The cross section and analyzing power of the pol{p}p -> pn pi+ reaction near threshold are estimated in terms of data obtained from the pol{p}p -> d pi+ and pp -> pp pi0 reactions. A simple final state interaction theory is developed which…
We study the properties of the Resonance-Spectrum Expansion near threshold in I=0 S-wave pion-pion scattering. The real part of the amplitude, when extrapolated from above threshold to below threshold, is found to vanish at a positive…
The results of a lattice simulation of time-separated charge overlap for the charged pion are discussed. The expected result $\sim {\rm exp}[-(E_q - m_{\pi})t\,]$ for large charge density overlap time separations, $t$, is clearly visible in…
Spin-polarizabilities are predicted by calculating the cross-section difference $\sigma_{3/2}-\sigma_{1/2}$ from available data for the resonance couplings $A_{3/2}$ and $A_{1/2}$ and CGLN amplitudes. The forward spin-polarizabilities are…
We compute the $J/\psi \pi\to {charmed mesons}$ cross section using QCD sum rules. This cross section is important to distinguish the suppression in the production of $J/\psi$ through the dissociation by comoving pions and through the…
A new limit of pion form factor at very large $Q^2$ is obtained by using a pion wave function determined from an effective chiral field theory of mesons. It shows that when $Q^2>>(1.8GeV)^2$ the pion form factor reaches the asymptotic limit…
In order to test theories of fission cross-sections, it is desirable to measure the (n,f) cross-sections of both an isomeric state and the ground state of the same isotope of the same element. This would test the ability to calculate…
The energy-dependent cross section for $e^+e^-\to \eta\psi(2S)$ is measured at eighteen center of mass energies from 4.288 GeV to 4.951 GeV using the BESIII detector. Using the same data samples, we also perform the first search for the…
We discuss the implications of a recently proposed pattern of Lorentz symmetry violation on very high-energy cross sections. As a consequence of the breaking of local Lorentz invariance by the introduction of a fundamental length, $a$ , the…
The observed cross sections for $e^+e^-\rightarrow \mu^+\mu^-$ at energies from 3.8 to 4.6 GeV are measured using data samples taken with the BESIII detector operated at the BEPCII collider. We measure the muonic widths and determine the…
A recent publication reports that heavy-ion fusion cross sections at extreme subbarrier energies show a continuous change of their logarithmic slope with decreasing energy, resulting in a much steeper excitation function compared with…
We have recently presented a Regge description of pion-pion total cross sections valid above 1.4 GeV, consistent with the few existing experiments, factorization and crossing symmetry. In this note we show how it also describes a further…
We present evidence for the existence of a bound H-dibaryon, an I=0, J=0, s=-2 state with valence quark structure uuddss, at a pion mass of m_pi ~ 389 MeV. Using the results of Lattice QCD calculations performed on four ensembles of…
The cross section for exclusive $\pi^+\pi^-$ and $\pi^0\pi^0$ meson pairs production in peripheral ultrarelativistic heavy-ion collisions is calculated at the energy available at the CERN Large Hadron Collider, i.e., $\sqrt{s_{NN}}=3.5$…
We investigate the continuum limit of the low lying static-light meson spectrum using Wilson twisted mass lattice QCD with N_f = 2 dynamical quark flavours. We consider three values of the lattice spacing a ~ 0.051 fm, 0.064 fm, 0.080 fm…
An empirical fit is described to measurements of inclusive inelastic electron-proton cross sections in the kinematic range of four-momentum transfer $0 \le Q^2<8$ GeV$^2$ and final state invariant mass $1.1<W<3.1$ GeV. The fit is…
We propose a scale-invariant chiral perturbation theory of the pseudo-Nambu-Goldstone bosons of the chiral symmetry (pion "pi") as well as the scale symmetry (dilaton "phi") for the large N_f QCD. The resultant dilaton mass M_phi reads…