0000000000469764
AUTHOR
M. Döring
showing 11 related works from this author
s-wave pion-nucleus optical potential
2007
We calculate the s-wave part of the pion-nucleus optical potential using a unitarized chiral approach that has been previously used to simultaneously describe pionic hydrogen and deuterium data as well as low energy pi N scattering in the vacuum. This energy dependent model allows for additional isoscalar parts in the potential from multiple rescattering. We consider Pauli blocking and pion polarization in an asymmetric nuclear matter environment. Also, higher order corrections of the pi N amplitude are included. The model can accommodate the repulsion required by phenomenological fits, though the theoretical uncertainties are bigger than previously thought. At the same time, we also find a…
Clues to the nature of the Δ∗(1700) resonance from pion- and photon-induced reactions
2006
Abstract We make a study of the π − p → K 0 π 0 Λ , π + p → K + π + Λ , K + K ¯ 0 p , K + π + Σ 0 , K + π 0 Σ + , and η π + p reactions, in which the basic dynamics is given by the excitation of the Δ ∗ ( 1700 ) resonance which subsequently decays into K Σ ∗ ( 1385 ) or Δ ( 1232 ) η . In a similar way we also study the γ p → K 0 π + Λ , K + π − Σ + , K + π + Σ − , K 0 π 0 Σ + , and η π 0 p related reactions. The cross sections are proportional to the square of the coupling of Δ ∗ ( 1700 ) to Σ ∗ K ( Δη ) for which there is no experimental information but which is provided in the context of coupled channels chiral unitary theory where the Δ ∗ ( 1700 ) is dynamically generated. Within present…
Radiative decay of the
2007
Abstract Electromagnetic properties provide information about the structure of strongly interacting systems and allow for independent tests of hadronic models. The radiative decay of the Δ ∗ ( 1700 ) is studied, which appears dynamically generated in a coupled channel approach from the rescattering of the ( 3 / 2 + ) decuplet of baryons with the ( 0 − ) octet of pseudoscalar mesons. The radiative decay is predicted from the well-known couplings of the photon to the mesons and baryons which constitute this resonance in the dynamical picture.
Recent Developments in Chiral Dynamics of Hadrons and Hadrons in Nuclei
2007
In this talk I present recent developments in the field of hadronic physics and hadrons in the nuclear medium. I review the unitary chiral approach to meson baryon interaction and address the topics of the two dynamically generated $\Lambda(1405)$ resonances, with experiments testing it, the $\Lambda(1520)$ and $\Delta(1700)$ resonances, plus the $\Lambda(1520)$, $\Sigma(1385)$ and $\omega$ in the nuclear medium.
Radiative decays of the Δ*(1700) and the Λ*(1520)
2008
Electromagnetic properties provide information about the structure of strongly interacting systems and allow for independent tests of hadronic models. The radiative decays of the Δ*(1700) and Λ*(1520) are studied, which appear dynamically generated in a coupled channel approach from the rescattering of the (3/2+) decuplet of baryons with the (0−) octet of pseudoscalar mesons. The radiative decays are predicted from the well-known couplings of the photon to the mesons and hadrons which constitute these resonances in the dynamical picture.
CHIRAL DYNAMICS IN THE π0η PHOTOPRODUCTION ON THE PROTON
2007
A theoretical model for the recently measured γp → π0ηp and related reactions is presented. These reactions are an interesting testing ground for existing γN → ππN models in an extension to SU(3). The chiral unitary schemes in which the N*(1535) and Δ*(1700) appear dynamically generated predict the dominant resonance couplings in the two-meson production processes.
Radiative decay of theΛ*(1520)
2006
A recently developed nonperturbative chiral approach to dynamically generate the 3/2{sup -} baryon resonances has been extended to investigate the radiative decays {lambda}*(1520){yields}{gamma}{lambda}(1116) and {lambda}*(1520){yields}{gamma}{sigma}{sup 0}(1193). We show that the {lambda}*(1520) decay into {gamma}{lambda} is an ideal test for the need of extra components of the resonance beyond those provided by the chiral approach since the largest meson-baryon components give no contribution to this decay. The case is different for {gamma}{sigma} decay, where the theory agrees with experiment, though the large uncertainties of these data call for more precise measurements. Some estimates…
Chiral dynamics in theγp→π0ηpandγp→π0K0Σ+reactions
2006
Using a chiral unitary approach for meson-baryon scattering in the strangeness zero sector, where the ${N}^{*}(1535){S}_{11}$ resonance is dynamically generated, we study the reactions $\ensuremath{\gamma}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}\ensuremath{\eta}p$ and $\ensuremath{\gamma}p\ensuremath{\rightarrow}{\ensuremath{\pi}}^{0}{K}^{0}{\ensuremath{\Sigma}}^{+}$ at photon energies at which the final states are produced close to threshold. Among several reaction mechanisms, we find the most important is the excitation of the ${\ensuremath{\Delta}}^{*}(1700){D}_{33}$ state, which subsequently decays into a pseudoscalar meson and a baryon belonging to the $\ensuremath{\Delta}(1232)…
Determination of the S-wave pion nucleon scattering lengths from πN, pionic hydrogen and deuteron
2005
The isoscalar and isovector scattering lengths ( b 0 , b 1 ) are determined using a unitarized coupled channel approach based on chiral Lagrangians. For the deuterium scattering length a π − d new significant corrections are evaluated, putting new constraints from π − d scattering on the values of ( b 0 , b 1 ) .
Charge fluctuations and electric mass in a hot meson gas
2006
Net-Charge fluctuations in a hadron gas are studied using an effective hadronic interaction. The emphasis of this work is to investigate the corrections of hadronic interactions to the charge fluctuations of a non-interacting resonance gas. Several methods, such as loop, density and virial expansions are employed. The calculations are also extended to SU(3) and some resummation schemes are considered. Although the various corrections are sizable individually, they cancel to a large extent. As a consequence we find that charge fluctuations are rather well described by the free resonance gas.
Predictions for the $\bar B^0 \to \bar K^{*0} X (YZ)$ and $\bar B^0_s \to \phi X (YZ)$ with $X(4160), Y(3940), Z(3930)$
2015
We investigate the decay of $\bar B^0 \to \bar K^{*0} R$ and $\bar B^0_s \to \phi R$ with $R$ being the $X(4160)$, $Y(3940)$, $Z(3930)$ resonances. Under the assumption that these states are dynamically generated from the vector-vector interaction, as has been concluded from several theoretical studies, we use a reaction mechanism of quark production at the elementary level, followed by hadronization of one final $q \bar q$ pair into two vectors and posterior final state interaction of this pair of vector mesons to produce the resonances. With this procedure we are able to predict five ratios for these decays, which are closely linked to the dynamical nature of these states, and also predic…