Related papers: Dilepton excess from local parity breaking in bary…
A search for new particles (X) that decay to electron or muon pairs has been performed using approximately 200 pb**(-1) of pbarp collision data at sqrt(s)=1.96 TeV collected by the CDF II experiment at the Fermilab Tevatron. Limits on…
A significant asymmetry in baryon/antibaryon yields in the central region of high energy collisions is observed when the initial state has non-zero baryon charge. This asymmetry is connected with the possibility of baryon charge diffusion…
We investigate the ability of LEP2 to detect possible $R$-parity violation, especially for the case where direct production cross-sections are too small for all superparticles. We demonstrate that for coupling strengths allowed by present…
We investigate dilepton production in transport-based approaches and show that the baryon couplings of the $\rho$ meson represent the most important ingredient for understanding the measured dilepton spectra. At low energies (of a few GeV),…
Today's accelerator facilities used for studies of relativistic heavy-ion collisions cover an energy range spanning over three orders of magnitude, from a few GeV up to a few TeV in center-of-mass energy per nucleon pair ($\sqrt{s_{NN}}$).…
We consider the signals of pair-produced charginos in an $e^{+}e^{-}$ collider, in a scenario where R-parity is spontaneously broken. The possibility of lepton-chargino mixing, together with the presence of a Majoron, opens up the two-body…
Strong upper bounds are derived on certain product combinations of lepton nonconserving couplings in the minimal supersymmetric standard model with explicit $R$-parity violation. The input is information from rare leptonic decays of the…
Dilepton and direct photon measurements in heavy ion collisions provide access to the early stages of the collision. Dilepton continuum measurements at SPS and RHIC show an excess consistent with broadening of the rho meson spectral…
The multiplicity distributions of hadrons produced in central nucleus-nucleus collisions are studied within the hadron-resonance gas model in the large volume limit. The microscopic correlator method is used to enforce conservation of three…
We study the possibility of $\rho-a_0$ mixing via N-N excitations in dense nuclear matter. This mixing is found to induce a peak in the dilepton spectra at an invariant mass equal to that of the $a_0$. We calculate the cross section for…
Dilepton production in heavy ion collisions, in the Intermediate Mass Region (IMR) has consistently shown an excess over theoretical estimates. An attempt to understand this discrepancy between the observed dilepton pairs and the…
Using a data set of electron-positron collisions corresponding to an integrated luminosity of ${\rm 2.93~fb^{-1}}$ taken with the BESIII detector at a center-of-mass energy of 3.773 GeV, a search for the baryon ($B$) and lepton ($L$) number…
The recent excess over the Standard Model prediction in the \mu \gamma missing-E_T channel reported by CDF can be well-explained by resonant smuon production with a single dominant R-parity violating coupling \lambda'_{211}, in the context…
Interactions that manifest themselves as lepton number violating processes at low energies in combination with sphaleron transitions typically erase any preexisting baryon asymmetry of the Universe. In this article, we discuss the…
Dilepton and photon production in heavy-ion collisions at SPS energies are studied in the relativistic transport model that incorporates self-consistently the change of hadron masses in dense matter. It is found that the dilepton spectra in…
The breaking of the Lam-Tung relation in the Drell-Yan process at the LHC exhibits a long-standing tension with the Standard Model (SM) prediction at $\mathcal{O}(\alpha_s^3)$ accuracy. This tension could be explained by weak dipole…
The yield of muon pairs in the invariant mass region 1<M<2.5 GeV/c^2 produced in heavy-ion collisions significantly exceeds the sum of the two expected contributions, Drell-Yan dimuons and muon pairs from the decays of D meson pairs. These…
Heavy ion collisions at extremely high energy, such as the top energy at RHIC, exhibit the property of transparency where there is a clear separation between the almost net-baryon-free central rapidity region and the net-baryon-rich…
We argue that there should exist the large combined fluctuations of chiral and diquark condensates along the phase boundary of QCD at moderately high density and relatively low temperature. Such fluctuations might lead to anomalous…
In this contribution we will discuss the production of low mass dileptons in SPS-energy heavy ion collisions. We briefly review the current theoretical situation before we turn to the analysis of the recent data for Pb+Au. We also will…