Related papers: Pion Interactions in the X(3872)
Fits of pion-nucleus potentials to large sets of pionic atom data reveal departures of parameter values from the corresponding free $\pi N$ parameters. These medium effects can be quantitatively reproduced by a chiral-motivated model where…
Effective field theory provides a powerful framework to exploit a separation of scales in physical systems. In these lectures, we discuss some general aspects of effective field theories and their application to few-body physics. In…
In the effective field theory formalism nuclear forces are organized as a low energy expansion. Usually the lowest order in this expansion corresponds to the non-perturbative iteration of the one-pion exchange potential and a few…
We show that the tail of the chiral two-pion exchange nucleon-nucleon potential is proportional to the $\pi N$ scalar form factor and discuss how it can be translated into effective scalar meson interactions. We then construct a kernel for…
We carefully calculate the nucleon-nucleon interaction due to two pion exchange processes by properly evaluating the corresponding Feynman diagrams. In the estimation, we have made no approximation, and instead, we carry out the numerical…
We show that, within a meson-exchange dynamical model describing most of the existing pion electromagnetic production data up to the second resonance region, one is also able to obtain a good agreement with the pi0 photo- and…
The thermal corrections to the propagator of a loosely bound charm-meson molecule in a pion gas are calculated to next-to-leading order in the heavy-meson expansion using a zero-range effective field theory. Ultraviolet divergences in the…
The pion structure function is investigated in a simple model, where pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi-> gamma* pi scattering amplitude is…
This report describes the transitions pion -> meson_1 + meson_2 and also pion -> multi-pion for high energy pions interacting with target nuclei (Z,A). The physics interests are: A) Nuclear inelastic coherent diffraction cross sections for…
In light of recent high-precision data taken by the BESIII Collaboration, we reconsider the dipion transition $\psi(3686) \rightarrow J/\psi \pi^+\pi^-$. The strong pion-pion final-state interactions are taken into account…
If the X(3872) is a loosely-bound molecule of the charm mesons D^0 \bar D^{*0} and D^{*0} \bar D^0, it can decay through the decay of a constituent in a hadronic channel with a nearby threshold, such as J/\psi \omega or J/\psi \rho. The…
The production of mesons in nucleon-nucleon collisions is reviewed from the viewpoint of the meson-exchange picture. In the first part various possible production mechanisms and their relative importance are discussed. In addition, general…
We show the results obtained for the cross sections of the processes $\bar D D$, $\bar D^* D$, $\bar D^* D^*\to\pi X(3872)$, information which is necessary to determine the $X(3872)$ abundance in heavy ion collisions. Our formalism is based…
Peripheral nucleon-nucleon scattering is analysed in the framework of an effective field theory. Distorted-wave methods are used to remove the effects of one-pion exchange. Two-pion exchange and recoil corrections to one-pion exchange are…
We have determined the production cross sections of the $X(3872)$ state in the reactions $\bar D D\to\pi X$, $\bar D^* D\to \pi X$ and $\bar D^* D^*\to\pi X$, information which is useful for studies of the $X(3872)$ meson abundance in heavy…
We present the two-pion exchange contributions to the nucleon-nucleon interaction up to next-to-next-to-next-to leading order (N$^3$LO) in covariant baryon chiral perturbation theory. Both one-loop and two-loop diagrams are calculated with…
Neutral current single pion production induced by neutrinos and antineutrinos on nucleon targets has been investigated in manifestly relativistic baryon chiral perturbation theory with explicit $\Delta(1232)$ degrees of freedom up to…
Assuming that $X(3872)$ is a mixture between $2P$ charmonium and $\bar{D}D^{*}$ molecular states with $J^{PC}=1^{++}$, an analysis of $X(3872)$ radiative decays into $J/\psi \gamma$ and $\psi(2S)\gamma$ is presented. The modification of the…
The polarizabilities of light pseudoscalar mesons can be extracted from differential cross sections for Compton scattering near threshold. While this has been accomplished for charged pions employing Primakoff reactions, a corresponding…
The X(3872) resonance is considered as a hadronic molecule, a loosely-bound state of charmed D0 and D*0 mesons, since its mass is very close to the D*0 barD0 threshold. Assuming structure and quantum numbers of X(3872) as (D0 barD*0 - D*0…