Related papers: Pion Interactions in the X(3872)
We adopt the heavy baryon chiral perturbation theory to calculate the $\Sigma_cN$ interaction to the next-to-leading order. We consider the contact interactions, one-pion-exchange contributions, two-pion-exchange diagrams, and…
For interactions involving two or more nucleons it is useful to divide pions into three classes: potential, radiation, and soft. The momentum threshold for the production of radiation pions is $Q_r = \sqrt{M_N m_\pi}$. We show that…
Transport models cannot simultaneously explain very recent data on pion multiplicities and pion charged ratios of Sn+Sn in the reaction at 0.27 A GeV. This stimulates further investigations on the pion dispersion relation, in-medium…
Motivated by the renewed interest in studying the pion production on nuclei with protons at few GeV incident energies, we investigate the pion production in proton-proton collisions over an energy range of 300 $MeV$ to 2 $GeV$. Starting…
Pion exchange in S-wave between hadrons that are themselves in a relative S-wave can shift energies by hundreds of MeV. In the case of charmed mesons $D,D^*,D_0,D_1$ a spectroscopy of quasi-molecular states may arise consistent with…
The meson $X(3872)$ and several related states appear to be, at least in part, hadronic molecules in which a heavy flavored meson (such as $D^0$) is bound to another heavy meson (such as $\bar D^{*0}$). Although not the only effect…
This is a revised version of a talk given at the Chiral Dynamics Workshop at M.I.T., July 25, 1994. It reports results in three areas: (1) The isospin-violating interactions between one non-relativistic nucleon and any number of soft pions…
A dispersion framework, appropriate for discussing the low-energy pion-nucleon interaction, is reviewed. Sensitivity of the isoscalar D-amplitude at the unphysical Cheng-Dashen point to input from different phase shift analyses and…
Pions produced via the $D^{+} \to \pi^{+} \overline{K^{0}}$ decay are in an entangled superposition of energy states because the $\overline{K^{0}}$ is not a mass eigenstate. This presents an opportunity to access kaon mixing parameters via…
Pion exchange is the central ingredient to nucleon-nucleon interactions used in nuclear structure calculations, and one pion exchange (OPE) enters at leading order in chiral effective field theory. In the $^{2S+1}L_J={^1S_0}$ partial wave,…
We study the pionic decay of a possible dibaryon d' --> N N \pi in the microscopic quark shell model. The initial d' dibaryon wave function (J^P=0^-, T=0) consists of one 1\hbar\omega six-quark shell-model s^5p[51]_X configuration. The most…
After a brief survey of effective field theories, the linear sigma model is discussed as a prototype of an effective field theory of the standard model below the chiral-symmetry-breaking scale. Although it can serve as a toy model for the…
Under chiral effective field theory, we study the $S$-wave $DD^*$ interactions up to second chiral order at one-loop level, which contain full contact, one-pion-exchange (OPE) and two-pion-exchange (TPE) contributions. Here, we adopt a new…
In a Poincare'-covariant vector-boson-exchange theory, the pion possesses components of pseudovector origin, which materially influence its observable properties. For a range of such quantities, we explore the consequences of a…
Elastic pion-pion and pion-nucleon scattering are reviewed in the context of chiral perturbation theory. Theoretical results from systematic low-energy expansions to O(p^6) for pion-pion and to O(p^3) for pion-nucleon scattering are…
We study the perturbative renormalizability of chiral two pion exchange in nucleon-nucleon scattering for p- and d-waves within the effective field theory approach. The one pion exchange potential is fully iterated at the leading order in…
We consider the two-nucleon weak interaction with a pionless effective field theory. Dibaryon fields are introduced to facilitate calculations and ensure precision in the initial and final state propagators. Weak interactions are accounted…
The interaction mediated by irreducible pion and gluon exchange between constituent quarks is calculated and shown to have a strong tensor component, which tends to cancel the pion exchange tensor interaction between quarks. Its spin-spin…
We study the role of pions in hot dense matter encountered in astrophysics. We find that strong interactions enhance the number density of negatively charged pions and that this enhancement can be calculated reliably for a relevant range of…
The quantum numbers J^PC = 1++ of the X(3872) and the proximity of its mass to the D*0 anti-D0 threshold imply that it is either a loosely-bound hadronic molecule whose constituents are a superposition of D*0 anti-D0 and D0 anti-D*0 or it…