Related papers: Pion Interactions in the X(3872)
We revisit the $DD^\ast$ interactions in chiral effective field theory up to the third order for the first time. We deal with the pion-exchanged interactions via local momentum-space regularization, in which we focus on their long-range…
We address the problem of pion production in low energy $\pi$-nucleus collisions. For the production mechanism we assume a simple model consisting of a coherent sum of single pion exchange and the excitation---followed by the decay into two…
We study the low energy pion-hyperon interaction considering effective non-linear chiral invariant Lagrangians including pions, rho mesons, hyperons and corresponding resonances. Then we calculate the S- and P-wave phase-shifts, total cross…
We discuss the possible power counting schemes that can be applied in the effective field theory description of heavy meson molecules, such as the X(3872) or the recently discovered Zb(10610) and Zb(10650) states. We argue that the effect…
XEFT is a low-energy effective field theory for charm mesons and pions that provides a systematically improvable description of the X(3872) resonance. A Galilean-invariant formulation of XEFT is introduced to exploit the fact that mass is…
As the residual interaction of quantum chromodynamics in low-energy region, the nucleon-nucleon (NN) potential can only be exactly described by the model picture now. In the Bonn potential, one of the most well-known NN interaction models,…
Understanding pion production in nucleon-nucleon collisions near threshold has been a challenge for the last decades. In particular, the reaction pp -> pppi0 is highly sensitive to short-range mechanisms, because isospin conservation…
The existence of the $X(3872)$ resonance extremely close to the $D^{*0} \bar{D}^0$ threshold implies that neutral charm mesons have an approximate nonrelativistic conformal symmetry. Systems consisting of these mesons with small kinetic…
We study the charge correlations between charm mesons produced in 500 GeV pi- - N interactions and the charged pions produced closest to them in phase space. With 110,000 fully reconstructed D mesons from experiment E791 at Fermilab, the…
If the quantum numbers of the X(3872) are J^{PC}=1^{++}, the measurement of its mass implies that it is either a loosely-bound hadronic molecule whose constituents are a superposition of the charm mesons pairs D^{*0} Dbar^0 and D^0…
We study the reaction of pion photoproduction on the nucleon in the framework of chiral perturbation theory with explicit $\Delta(1232)$ degrees of freedom. In the covariant approach, we give results up to order $\epsilon^3$ in the small…
Pionful nuclear effective field theory (NEFT) in the two-nucleon sector is examined from the Wilsonian renormalization group point of view. The pion exchange is cut off at the floating cutoff scale, $\Lambda$, with the short-distance part…
Chiral perturbation theory is the effective field theory of the strong interactions at low energies. We will give a short introduction to chiral perturbation theory for mesons and will discuss, as an example, the electromagnetic…
A meson exchange model of the $\pi\pi$ interaction which fits free $\pi\pi$ scattering data is used to calculate the interactions of pions in nuclear matter as a function of nuclear density. Polarization of the nuclear medium by the pions…
The behavior of the pion dispersion relation in a pion medium is strongly modified by the introduction of a finite chemical potential associated to the finite pion number density. Such behavior is particularly important during the hadronic…
In this work, dispersion relations of $\pi^0$ and $\pi^{\pm}$ have been studied in vacuum in the limit of weak external magnetic field using a phenomenological pion-nucleon $(\pi N)$ Lagrangian. For our purpose, we have calculated the…
A resonance model for two-pion production in the pion-nucleon reaction is developed that includes information obtained in the analysis of pion-nucleon scattering in a meson-exchange model. The baryonic resonances Delta(1232), N*(1440),…
Both the mass (just below the D^{*0}Dbar^0 threshold) and the likely quantum numbers (J^{PC}=1^{++}) of the X(3872) suggest that it is either a weakly-bound hadronic ``molecule'' or a virtual state of charmed mesons. Assuming the X(3872) is…
Effective field theory techniques are used to describe the interaction of heavy hadrons in a model independent way. Predictability is obtained by exploiting the symmetries of QCD. Heavy hadron chiral perturbation theory is reviewed and used…
We re-investigate the possibility of X(3872) as a $D\bar{D}^*$ molecule with $J^{PC}=1^{++}$ within the framework of both the one-pion-exchange (OPE) model and the one-boson-exchange (OBE) model. After careful treatment of the S-D wave…