Large enhancement of (anti)protons relative to pions has been observed at intermediate p T ∼ 2-5 GeV/c in central Au+Au collisions at RHIC. To investigate the possible source of this baryon enhancement, we performed a systematic study of identified hadron spectra in Au+Au and Cu+Cu collisions at √ s N N = 200 GeV, and Au+Au collisions at √ s N N = 62.4 GeV. The data set allows us to study the e...

We discuss the puzzling experimental results on baryon-antibaryon production in ee annihilation close to the threshold, in particular the fact that σ(ee → n̄n) > ∼ σ(ee → p̄p). We discuss an interpretation in terms of a two-step process, via an intermediate coherent isovector state serving as an intermediary between ee and the baryon-antibaryon system. We provide evidence that the isovector chann...

The baryon production mechanism at the intermediate pT (2 5 GeV/c) at RHIC is still not well understood. The beam energy scan data in Cu+Cu and Au+Au systems at RHIC may provide us a further insight on the origin of the baryon anomaly and its evolution as a function of √ sNN . In 2005 RHIC physics program, the PHENIX experiment accumulated the first intensive low beam energy data in Cu+Cu colli...

An extension of the Standard Model by three right-handed neutrinos with masses smaller than the electroweak scale (the νMSM) can explain simultaneously dark matter and baryon asymmetry of the Universe, being consistent with the data on neutrino oscillations. A dark matter candidate in this theory is the sterile neutrino with the mass in keV range. We discuss the constraints on the properties of...

The process of baryon number transfer due to string junction propagation in rapidity is considered. It has a significant effect in the net baryon production in pp collisions at mid-rapidities and an even larger effect in the forward hemisphere in the cases of πp and γp interactions. The results of numerical calculations in the framework of the QuarkGluon String Model are in reasonable agreement...

We present a complete computation of the inflaton decay into very massive fermions during preheating, including back-reaction effects. We show that heavy fermions are produced very efficiently up to masses of order 10–10 GeV; the accessible mass range is thus even broader than the one for heavy bosons. We apply our findings to the leptogenesis scenario, proposing a new version of it, in which t...

Leading charm hadrons produced in hadron-nucleus interactions cannot be adequately described within the parton fusion model. Recent results on charm baryon production in X A interactions at 330 GeV with the WA89 detector disagree with fusion predictions. Intrinsic heavy quark pairs in the Z (dds) wavefunction provide a simple mechanism for producing fast charm hadrons. We calculate leading char...

The narrow width of the exotic narrow baryon resonance Θ might be explained by mixing between the two nearly degenerate states that arise in models with two diquarks and an antiquark. The only open Θ decay channel is KN . When two states both coupled to a single dominant decay mode are mixed by the loop diagram via this decay mode, diagonalization of the loop diagram decouples one mass eigensta...

We study stochastic gravitational wave production and baryon number generation at electroweak phase transition with the two Higgs doublet models. The produced during strongly first-order can be probed by future space-based interferometers. nonlocal baryogenesis cannot address observed Baryon asymmetry of Universe successfully in parameter spaces due to CP violation is severely bounded electron ...

The Minimal Flavor Violation hypothesis (MFV) is extended to the R-parity violating MSSM, supplemented with a simple seesaw mechanism. The requirement of MFV is shown to suppress lepton and baryon-number violating couplings sufficiently to pass all experimental bounds, in particular those for proton decay, and is thus a viable alternative to R-parity. The phenomenological consequences for FCNC,...