Constraints on the kinetic mixing parameter ${\epsilon }^2$ for the light dark photons from dilepton production in heavy-ion collisions in the few-GeV energy range

Abstract

The vector $U$-bosons, or so called 'dark photons', are one of the possible candidates for the dark matter mediators. They are supposed to interact with the standard matter via a 'vector portal' due to the $U(1)-U(1{)}^{\prime }$ symmetry group mixing which might make them visible in particle and heavy-ion experiments. While there is no confirmed observation of dark photons, the detailed analysis of different experimental data allows to estimate the upper limit for the kinetic mixing parameter ${\epsilon }^2$ depending on the mass $M_U$ of $U$-bosons which is also unknown. In this study we present theoretical constraints on the upper limit of ${\epsilon }^2(M_U)$ in the mass range $M_U\le 0.6$ GeV from the comparison of the calculated dilepton spectra with the experimental data from the HADES Collaboration at SIS18 energies where the dark photons are not observed. Our analysis is based on the microscopic Parton-Hadron-String Dynamics (PHSD) transport approach which reproduces well the measured dilepton spectra in $p+p$, $p+A$ and $A+A$ collisions. Additionally to the different dilepton channels originating from interactions and decays of ordinary matter particles (mesons and baryons), we incorporate the decay of hypothetical $U$-bosons to dileptons, $U\to e^{+}{e}^{-}$, where the $U$-bosons themselves are produced by the Dalitz decay of pions ${\pi }^0\to \gamma U$, $\eta$-mesons $\eta \to \gamma U$ and Delta resonances $\Delta \to NU$. Our analysis can help to estimate the requested accuracy for future experimental searches of 'light' dark photons by dilepton experiments.

arXiv comment11 pages, 5 figures, extended version, to be published in Phys. Rev. D

References in corpus (48)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• Secluded WIMP Dark Matter
• Scalar Dark Matter candidates
• The QCD transition temperature: results with physical masses in the continuum limit II.
• The QCD Equation of State with almost Physical Quark Masses
• Search for a dark photon in e+e- collisions at BABAR
• Physics Beyond Colliders at CERN: Beyond the Standard Model Working Group Report
• Excess Electronic Recoil Events in XENON1T
• Exploring Portals to a Hidden Sector Through Fixed Targets
• Parton-Hadron-String Dynamics: an off-shell transport approach for relativistic energies
• Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR
• Search for Invisible Decays of a Dark Photon Produced in e+e- Collisions at BaBar
• Probing a Secluded U(1) at B-factories
• Relativistic Transport Approach for Nucleus-Nucleus Collisions from SIS to SPS Energies
• Parton transport and hadronization from the dynamical quasiparticle point of view
• Search for light massive gauge bosons as an explanation of the $(g-2{)}_{\mu }$ anomaly at MAMI
• Parton-Hadron-String Dynamics at Relativistic Collider Energies
• From Kadanoff-Baym dynamics to off-shell parton transport
• Light spin-1/2 or spin-0 Dark Matter particles
• Effective QCD and transport description of dilepton and photon production in heavy-ion collisions and elementary processes
• Semiclassical transport of particles with dynamical spectral functions
• Dynamical quasiparticles properties and effective interactions in the sQGP
• Dilepton production and off-shell transport dynamics at SIS energies
• QCD thermodynamics and confinement from a dynamical quasiparticle point of view
• Dielectron production in Ar+KCl collisions at 1.76A GeV
• Antikaon production in A+A collisions at SIS energies within an off-shell G-matrix approach
• Semiclassical transport of hadrons with dynamical spectral functions in A+A collisions at SIS/AGS energies
• Exploring the partonic phase at finite chemical potential within an extended off-shell transport approach
• Nonequilibrium Quantum-Field Dynamics and Off-Shell Transport for ${\varphi }^4$-theory in 2+1 dimensions
• Thermal Dileptons from Coarse-Grained Transport as Fireball Probes at SIS Energies
• Chiral symmetry restoration in heavy-ion collisions at intermediate energies
• Di-Electron Bremsstrahlung in Intermediate-Energy pn and Dp Collisions
• Analysis of dilepton production in Au+Au collisions at sqrt(s_NN)=200 GeV within the Parton-Hadron-String Dynamics (PHSD) transport approach
• Chiral symmetry restoration versus deconfinement in heavy-ion collisions at high baryon density
• Inclusive dielectron spectra in p+p collisions at 3.5 GeV
• Rise of azimuthal anisotropies as a signature of the Quark-Gluon-Plasma in relativistic heavy-ion collisions
• First measurement of low momentum dielectrons radiated off cold nuclear matter
• Dilepton production and resonance properties within a new hadronic transport approach in the context of the GSI-HADES experimental data
• In-medium effects in strangeness production in heavy-ion collisions at (sub-)threshold energies
• System Size and Energy Dependence of Dilepton Production in Heavy-Ion Collisions at SIS Energies
• Open charm and dileptons from relativistic heavy-ion collisions
• Dilepton production in proton-proton and Pb+Pb collisions at sqrt(s_NN)=2.76 TeV
• QCD thermodynamics with continuum extrapolated Wilson fermions II
• Perspectives of $e^{+}{e}^{-}$ production in pp, pd and p Be reactions at SIS energies
• Dimuon radiation at the CERN SPS within a (3+1)d hydrodynamic+cascade model
• Energy, centrality and momentum dependence of dielectron production at collider energies in a coarse-grained transport approach
• Dilepton production in microscopic transport theory with in-medium $\rho$-meson spectral function

Cited by in corpus (3)

• Opportunities for new physics searches with heavy ions at colliders
• Effects of chiral symmetry restoration on meson and dilepton production in relativistic heavy-ion collisions
• Constraints on Kinetic Mixing of Dark Photons from Dilepton Spectra