相关论文: Pionic Deuterium

Modifications of Delta(1232) and nucleon spectral functions at finite temperature and baryon density are evaluated in terms of resonant scattering off thermal pions, as well as a renormalization of the vacuum Delta-width including vertex…

We study the lowest lying $\pi^+ \pi^-$ resonance R, bound by the long range Coulomb potential and destabilized by short range strong interactions mediating the dominant decay into two neutral pions. Parametrizing the corresponding partial…

Using non relativistic effective Lagrangian techniques, we analyze the hadronic decay of the pi+pi- atom and the strong energy-level shift of pionic hydrogen in the ground state. We derive general formulae for the width and level shift,…

Photoproduction of neutral and charged pions off nucleons and deuterium has been precisely calculated in baryon chiral perturbation theory. I review the predictions with the accurate data that have become available over the last few years.…

Recently a two-step process has been proposed for the double-pionic fusion to deuterium $pn (I=0) \to d\pi^+\pi^-$. Its calculation is solely based on total cross section data for the two sequential single-pion production steps $pn (I=0)\to…

In the near future, the DIRAC collaboration will measure pion-pion scattering lengths with great precision. Those measurements are likely to shed some light on the problem of the size of the chiral quark-antiquark condensate. Although it is…

The reaction ${n} {p} \to {p} {p} \pi^{-}$ has been studied in a kinematically complete measurement with a large acceptance time-of-flight spectrometer for incident neutron energies between threshold and 570 MeV. The proton-proton invariant…

We present first results on the scalar WIMP-pion coupling from 1 t$\times$yr of exposure with the XENON1T experiment. This interaction is generated when the WIMP couples to a virtual pion exchanged between the nucleons in a nucleus. In…

Pionium lifetime corrections are evaluated in the frameworks of constrained Bethe-Salpeter equation and chiral perturbation theory. Corrections of order $O(\alpha)$ are calculated with respect to the conventional lowest-order formula, in…

We show that diffractive production of a single neutral pion in photon-induced reactions at high energy is dynamically suppressed due to the approximate chiral symmetry of QCD. These reactions have been proposed as a test of the odderon…

Within a nuclear model that the deuteron has NN and \pi NN components, we derive convolution formula for investigating the Drell-Yan process in proton-deuteron (pd) reactions. The contribution from the \pi NN component is expressed in terms…

Study of the elastic scattering can produce a rich information on the dynamics of the strong interaction. The EPECUR collaboration is aimed at the research of baryon resonances in the second resonance region via pion-proton elastic…

We determine the $\Delta(1232)$ resonance parameters using lattice QCD and the L\"uscher method. The resonance occurs in elastic pion-nucleon scattering with $J^P=3/2^+$ in the isospin $I = 3/2$, $P$-wave channel. Our calculation is…

Within the framework of the quantum molecular dynamics transport model, the pion production and constraint of the high-density symmetry energy in heavy-ion collisions near threshold energy have been thoroughly investigated. The energy…

The muonic hydrogen experiment measuring the $2P-2S$ transition energy [R. Pohl {\em et al.}, Nature {\bf 466}, 213 (2010)] is significantly discrepant with theoretical predictions based on quantum electrodynamics. A possible approach to…

New data from the NA61 collaboration on the production of negative pions in p+p interactions at beam momenta between 20 and 158 GeV/c are critically compared to available results in the same energy range. It is concluded that the NA61 data…

The equation of state for the pion gas is analyzed within the third virial approximation. The second virial coefficient is found from the pion-pion- scattering data, while the third one is considered as a free parameter. The proposed model…

Strong pionic decays of baryons are studied in a non-relativistic quark model framework via a convergent (p/E) expansion of the transition operator. Results are compared to the ones obtained within a more conventional (p/m) expansion.

Differential cross sections of the gamma + d -> d + pi^0 reaction were measured at photon beam energies between 0.5 and 2.0 GeV over a wide angular range in CM system. The experiment was performed in Hall B at Jefferson Lab using the CLAS…

We provide an in-detail derivation through the $^3P_0$ pair creation model of the transition matrix for a baryon decaying into a meson-baryon system. The meson's analysis was conducted in Ref. [1] and we extend the same formalism to the…