Modern Physics Letters A

An extraction of the parton distributions of the proton by a next-to-leading order QCD fit in the framework of the Standard Model is presented. The fit implements a novel decomposition of the quark species into up- and down-type quark distributions, which is the key to enable a determination of flavor separated parton distributions from a single experiment. The fit is performed on the inclusive unpolarized neutral and charged current cross-section measurements by the H1 collaboration at HERA. The discussion of uncertainties of parton distribution functions is based upon but extends the QCD analysis published together with the H1 data.

The 511 keV gamma emission from the galactic core may originate from a high concentration (~ 10²²) of primordial black holes (PBHs) in the core, each of whose Hawking radiation includes ~ 10²¹ positrons per second. The PBHs we consider are taken as near the lightest with longevity greater than the age of the universe (mass ~ 10¹²kg; Schwarzschild radius ~ 1 fm). These PBHs contribute only a small fraction of cold dark matter, Ω_PBH ~ 10^-8. This speculative hypothesis, if confirmed implies the simultaneous discovery of Hawking radiation and an early universe phase transition.

We study a free particle system residing on a torus to investigate its Becci–Rouet–Stora–Tyutin symmetries associated with its Stückelberg coordinates, ghosts and anti-ghosts. By exploiting zeibein frame on the toric geometry, we evaluate energy spectrum of the system to describe the particle dynamics. We also investigate symplectic structures involved in the free particle system on the torus.

We introduce the fermion non-universality into the little Higgs models SU(5)/SO(5), SU(6)/Sp(6) and study the phenomenology of the new models. We find that if we change the transform property of the observed fermions under the extended [SU(2)×U(1)]², the cancellation of the one-loop quadratically divergent correction to the Higgs mass arising from gauge bosons will not be changed, whereas the phenomenology at W-pole, Z-pole and low q² will be changed.

Nuclear masses are calculated using the modified Bethe–Weizsäcker mass formula in which the isotonic shifts have been incorporated. The results are compared with the improved liquid drop model with isotonic shift. Mass excesses predicted by this method compares well with the microscopic–macroscopic model while being much more simple. The neutron and proton drip lines have been predicted using this modified Bethe–Weizsäcker mass formula with isotonic shifts.

The massive topologically and self-dual theories in seven dimensions are considered. The local duality between these theories is established and the dimensional reduction leads to different dualities for massive antisymmetric fields in four dimensions.

We investigate the spacetime of a global monopole in a five-dimensional spacetime in the presence of the cosmological term. Also the gravitational properties of the monopole solution are discussed.