相关论文: Matter-induced hadronic processes
We propose in this article that if the chemical potential exceeds a critical value in dense hadronic medium, a first-order phase transition to a new state of matter with Lorentz symmetry spontaneously broken (in addition to the explicit…
Photons and dileptons are emitted throughout the evolution of the deconfined nuclear medium produced in heavy ion collisions. As such they can provide valuable information about the different phases of the medium, and complement hadronic…
In this review we discuss the observable consequences of in-medium changes of hadronic properties in reactions with elementary probes, and in particular photons, on nuclei. After an outline of the theoretical method used we focus on a…
Nuclear processes in solid environment are investigated. It is shown that if a slow, quasi-free heavy particle of positive charge interacts with a "free" electron of a metallic host, it can obtain such a great magnitude of momentum in its…
Multiple parton interactions in relativistic heavy ion reactions result in transverse momentum diffusion and medium induced non-Abelian energy loss of the hard probes traversing cold and hot nuclear matter. A systematic study of the…
We first briefly review the theoretical basis for calculations of changes of hadronic properties in dense nuclear matter. These changes have usually been investigated by means of relativistic heavy-ion reactions. Here we discuss that…
The production of dileptons is studied within a hadronic transport model. We investigate the sensitivity of the dilepton spectra to the initial configuration of the hadronic phase in a ultrarelativistic heavy ion collision. Possible in…
The status of flow in heavy-ion collisions and of inference of hadronic-matter properties is reviewed.
We calculate a novel "magnetic contribution" to the dilepton spectrum in heavy-ion collisions arising from interaction of relativistic quarks with intense magnetic field. Synchrotron radiation by quarks, which can be approximated by the…
A possible mechanism for the formation of heavy-mass elements in supernovae is the rapid neutron-capture-mechanism (r-process). It depends upon the electron-fraction $Y_e$, a quantity which is determined by beta-decay-rates. In this paper,…
We report the first observation of exclusive $\rho$ production in ultra-peripheral collisions at RHIC. The $\rho$ are produced electromagnetically at large impact parameters where no hadronic interactions occur. The produced $\rho$ have a…
A systematic study of low mass dilepton production from $\pi-\rho$ interactions in a hot medium is presented. Applying finite temperature perturbation theory the dilepton rate, respectively the virtual photon rate, is computed up to order…
We discuss recent developments concerning the in-medium properties of hadrons in dense and hot matter. The theoretical approaches are discussed in connection with the interpretation of experimental data from intermediate energy machines up…
The scattering cross sections of charm mesons with hadrons such as the pion, rho meson, and nucleon are studied in an effective Lagrangian. In heavy ion collisions, rescattering of produced charm mesons by hadrons affects the invariant mass…
We show that several effects considered nuclear effects are not nuclear in the sense that they do not only occur in nucleus-nucleus and hadron-nucleus collisions but, as well, they are present in hadron-hadron (proton-proton) collisions.…
We summarize the current theoretical and experimental status of the spectral changes of vector mesons ($\rho$, $\omega$, $\phi$) in nuclear medium. Various approaches including QCD sum rules, effective theory of hadrons and bag models show…
The rare decays of mesons are higher order effects in weak interactions. The main contributions to such decay processes are from the Z-penguin, the photonpenguin and the box diagram. At the quark level, these contributions are well known.…
We point out that formation time of pions produced in heavy ion collisions modifies the mass spectrum of dileptons produced via pipi -> ee annihilation. Increasing formation time enhances the production of dileptons with lower masses. The…
At very high energy the same universal relation between the multiparticle or the transverse energy distribution associated to a rare event $C$, $P_C$ and the corresponding minimum bias distribution P, $P_C(\nu)\equiv \nu/<\nu> P(\nu)$,…
Through the analysis of HELIOS-3 data on dilepton spectra, we demonstrate the importance of secondary processes for the dilepton production in heavy-ion collisions in the intermediate mass region. We find that, while the dilepton spectra in…