Related papers: Medium Modifications of Vector Mesons and NA60
The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 AGeV In-In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. After subtraction of the decay sources, the shape of…
This article reviews the current status of experimental results obtained in the measurement of light vector mesons produced in proton-proton and heavy ion collisions at different energies. The review is focused on two phenomena related to…
We present recent results on in-medium spectral functions of vector and axial-vector mesons, the electromagnetic (EM) spectral function and dilepton rates using the Functional Renormalization Group (FRG) approach. Our method is based on an…
The NA60 experiment has studied low-mass muon pair production in proton-nucleus collisions with a system of Be, Cu, In, W, Pb and U targets using a 400 GeV/$c$ proton beam at the CERN SPS. The mass spectrum is well described by the…
Chiral symmetry is one of the most fundamental symmetries in QCD. It is closely connected to hadron properties in the nuclear medium via the reduction of the quark condensate <bar{q}q>, manifesting the partial restoration of chiral…
The constraints imposed by chiral symmetry on hadron correlation functions in nuclear medium are discussed. It is shown that these constraints imply a certain structure for the in-medium hadron correlators and lead to the cancelation of the…
The extended linear sigma model describes the vacuum phenomenology of scalar, pseudoscalar, vector and axial-vector mesons at energies \(\simeq 1\text{ GeV}\). We combine the chiral \(U(2)_L\times U(2)_R\) symmetry of this model with a…
The interactions of $\rho$, $K^*$, $\phi$ and $\omega$ vector-mesons with low-momentum $\pi$, $K$ and $\eta$ pseudoscalar mesons are constrained by chiral symmetry. We derive a heavy vector-meson chiral Lagrangian in which the vector mesons…
The NA60 experiment at the CERN SPS has measured muon pairs with unprecedented precision in 158A GeV In-In collisions. A strong excess of pairs above the known sources is observed in the whole mass region 0.2<M<2.6 GeV. The mass spectrum…
The NA60 experiment at the CERN SPS has studied muon-pair production in 158A GeV In-In collisions. The unprecedented precision of the data has allowed to isolate a strong excess of pairs above the known sources in the whole invariant mass…
Recent heavy ion experiments indicate modifications of the $\rho-$meson mass in medium. In the CERES experiments $\rho-$mesons are produced at $\sim$ normal nuclear matter density, where hadrons are more appropriate constituents than…
The linear sigma model we present here describes the vacuum phenomenology of the $N_F=2$ scalar, pseudoscalar, vector and axial-vector mesons at energies $\simeq 1\text{ GeV}$. Together with a local $SU(2)_L\times U(1)_Y$ symmetry obtained…
The medium modification of vector meson properties and its effects on thermal photon and dilepton emission rates from hot/dense hadronic matter are discussed. The role of spectral changes of hadrons in explaining the WA98 photon data and…
Modifications of the DGMLY relation for calculation of electromagnetic $\pi$-meson mass difference based on the Chiral Symmetry Restoration phenomenon at high energies as well as the Operator Product Expansion of quark densities for vector…
Rho meson propagation in hot hadronic matter is studied in a model with coupling to $\pi\pi$ states. Medium modifications are induced by a change of the pion dispersion relation through collisions with nucleons and $\Delta's$ in the…
We summarize the current theoretical and experimental status of the spectral changes of vector mesons ($\rho$, $\omega$, $\phi$) at finite baryon density. Various approaches including QCD sum rules, effective theory of hadrons and bag…
We discuss medium modifications of the unitarized pion-pion interaction in the nuclear medium. We incorporate both the effects of chiral symmetry restoration and the influence of collective nuclear pionic modes, originating from the p-wave…
The in-medium masses of the light vector, $\rho^{0, \pm}$, $\omega$ and the light axial-vector, $A_1^{0, \pm}$ mesons, are studied in the magnetized nuclear matter, accounting for the effects of the Dirac sea. The in-medium partial decay…
The in-medium properties of the vector mesons are known to be modified significantly in hot and dense hadronic matter due to vacuum polarisation effects from the baryon sector in the Walecka model. The vector meson mass drops significantly…
We will summarize the progress in understanding the changes in the vector meson spectral density in nuclear medium using the constraint equations obtained from the Borel transformed dispersion relation and QCD Operator Product Expansion. We…