On the Extraction of Cross Sections for pi0 and eta Photoproduction off Neutrons from Deuteron Data

We discuss the procedure of extracting the photoproduction cross section for neutral pseudoscalar mesons off neutrons from deuteron data. The main statement is that the final-state interaction (FSI) corrections for the proton and neutron target are in general not equal, but for pi0 production there are special cases were they have to be identical and there are large regions in the parameter space of incident photon energy and pion polar angle, theta^*, where they happen to be quite similar. The corrections for both target nucleons are practically identical for $pi_0$ production in the energy range of the Delta(1232)3/2+ resonance due to the specific isospin structure of this excitation. Also above the $Delta$-isobar range large differences between proton and neutron correction factors are only predicted for extreme forward angles ($theta^*$ < 20 deg), but the results are similar for larger angles. Numerical results for the gp-->pi0p and gn-->pi0n correction factors are discussed. Also the model description for the available data on the differential gd-->pi0pn cross sections are given.

Gold-plated moments of nucleon structure functions in baryon chiral perturbation theory

We obtain leading- and next-to-leading order predictions of chiral perturbation theory for several prominent moments of nucleon structure functions. These free-parameter free results turn out to be in overall agreement with the available empirical information on nearly all of the considered moments, in the region of low-momentum transfer ($Q^2 < 0.3$ GeV$^2$). Especially surprising is the situation for the spin polarizability $delta_{LT}$, which thus far was not reproducible in chiral perturbation theory for proton and neutron simultaneously. This problem, known as the $delta_{LT}$ puzzle, is not seen in the present calculation.

Stars and Black Holes from the very Early Universe

A mechanism of creation of stellar-like objects in the very early universe, from the QCD phase transition till BBN and somewhat later, is studied. It is argued that in the considered process primordial black holes with masses above a few solar masses up to super-heavy ones could be created. This may explain an early quasar creation with evolved chemistry in surrounding medium and the low mass cutoff of the observed black holes. It is also shown that dense primordial stars can be created at the considered epoch. Such stars could later become very early supernovae and in particular high redshift gamma-bursters. In a version of the model some of the created objects can consist of antimatter.

A photon-proton marriage

The shapes of invariant differential cross section for charged hadron production as function of hadrons transverse momentum and rapidity in ep collisions at HERA machine are considered. The particle spectra shapes observed in pp and gamma-gamma collisions before have shown very different properties. This difference could be directly measured in the mixed type collisions of photon and proton at HERA experiments.

A variation of the charged particle spectrum shape as function of rapidity in high energy pp collisions

The shapes of invariant differential cross section for charged particle production as function of transverse momentum measured in pp collisions by the UA1 detector are analyzed. The spectra shape varies with the produced particles pseudorapidity changing. To describe this and several other recently observed effects a simple qualitative model for hadroproduction mechanism was proposed.

An analysis of charged particles spectra in events with different charged multiplicity

The shapes of invariant differential cross section for charged particle production as function of transverse momentum measured in $pp$ collisions by the STAR detector are analyzed. The spectra shape varies with the event charged multiplicity changing. To describe this and several other recently observed effects a simple qualitative model for hadroproduction mechanism was proposed.

Comparative Analysis of Pion, Kaon and Proton Spectra Produced at PHENIX

The shapes of invariant differential cross section for identified pi,K, p and pbar production as function of transverse momentum measured in pp collisions by the PHENIX detector are analyzed. Simultaneous fit of these data to the sum of exponential and power-law terms show significant difference in the exponential term contributions. This effect qualitatively explains the observed shape of the experimental K/pi and p/pi yield ratios measured as function of transverse momentum of produced hadrons. A picture with two types of mechanisms for hadron production is given.

Modification of Coulomb law and energy levels of the hydrogen atom in a superstrong magnetic field

We obtain the following analytical formula which describes the dependence of the electric potential of a point-like charge on the distance away from it in the direction of an external magnetic field B: Phi(z) = e/|z| [ 1- exp(-sqrt{6m_e^2}|z|) + exp(-sqrt{(2/pi) e^3 B + 6m_e^2} |z|) ]. The deviation from Coulombs law becomes essential for B > 3pi B_{cr}/alpha = 3 pi m_e^2/e^3 approx 6 10^{16} G. In such superstrong fields, electrons are ultra-relativistic except those which occupy the lowest Landau level (LLL) and which have the energy epsilon_0^2 = m_e^2 + p_z^2. The energy spectrum on which LLL splits in the presence of the atomic nucleus is found analytically. For B > 3 pi B_{cr}/alpha, it substantially differs from the one obtained without accounting for the modification of the atomic potential.

Asymptotic effects in jet production at high energies

Monte Carlo event simulation with BFKL evolution is discussed. We report current status of a Monte Carlo event generator ULYSSES with BFKL evolution implemented. The ULYSSES, based on Pythia Monte Carlo generator, would help to reveal BFKL effects at LHC energies. In particular, such an observable as dijet K-factor can serve as a source of BFKL dynamics at the LHC, and it would also help to search for new physics.

Measurements of Phi_1 and Phi_2 by Belle and Babar

We report recent measurements of the Unitarity triangle angles phi_1 and phi_2 using large data samples collected with Belle and BaBar detectors at e+e- asymmetric-energy colliders.