0000000000765489

AUTHOR

W Langgartner

showing 2 related works from this author

In-medium modifications of the pi pi interaction in photon-induced reactions

2002

Differential cross sections of the reactions $(\gamma,\pi^\circ\pi^\circ)$ and $(\gamma,\pi^\circ\pi^++\pi^\circ\pi^-)$ have been measured for several nuclei ($^1$H,$^{12}$C, and $^{\rm nat}$Pb) at an incident-photon energy of $E_{\gamma}$=400-460 MeV at the tagged-photon facility at MAMI-B using the TAPS spectrometer. A significant nuclear-mass dependence of the $\pi\pi$ invariant-mass distribution is found in the $\pi^\circ\pi^\circ$ channel. This dependence is not observed in the $\pi^\circ\pi^{+/-}$ channel and is consistent with an in-medium modification of the $\pi\pi$ interaction in the $I$=$J$=0 channel. The data are compared to $\pi$-induced measurements and to calculations within …

PhysicsPhotonMesonPAIRSHadronCarbon-12General Physics and AstronomyElementary particleNONPERTURBATIVE APPROACHCHIRAL-SYMMETRY RESTORATIONPionNUCLEAR MEDIUMPiSPECTROMETERMESONAtomic physicsNuclear ExperimentNuclear ExperimentMATTERBoson
researchProduct

Direct Observation of aρDecay of theD13(1520)Baryon Resonance

2001

The reaction {gamma}p{yields}{pi}{sup +}{pi}{sup 0}n has been measured at MAMI for photon energies up to 820MeV. Invariant mass spectra of the particles in the final state ({pi}{sup +}n) , ({pi}{sup 0}n) , ({pi}{sup +}{pi}{sup 0}) have been determined for several bins of incident photon energy. Differences in {pi}{sup +}{pi}{sup 0} and simultaneously measured {pi}{sup 0}{pi}{sup 0} invariant mass distributions are assigned to a {rho} branch of the D{sub 13}(1520) nucleon resonance.

PhysicsProton010308 nuclear & particles physicsGeneral Physics and AstronomyResonancePhoton energy01 natural sciencesSpectral lineBaryon0103 physical sciencesMass spectrumInvariant massAtomic physics010306 general physicsNucleonPhysical Review Letters
researchProduct