225 research outputs found
Dynamical quark loop light-by-light contribution to muon g-2 within the nonlocal chiral quark model
The hadronic corrections to the muon anomalous magnetic moment a_mu, due to
the gauge-invariant set of diagrams with dynamical quark loop light-by-light
scattering insertions, are calculated in the framework of the nonlocal chiral
quark model. These results complete calculations of all hadronic light-by-light
scattering contributions to a_mu in the leading order in the 1/Nc expansion.
The result for the quark loop contribution is
a_mu^{HLbL,Loop}=(11.0+-0.9)*10^(-10), and the total result is
a_mu^{HLbL,NxQM}=(16.8+-1.2)*10^(-10).Comment: 11 pages, 5 figures, 1 tabl
Transition form factor of γ → 3π in a nonlocal quark model
The transition form factor of a gamma into three pions F3π are studied in a framework of nonlocal chiral quark model. In local limit the result is agreement with chiral perturbative theory and reproduce Wess-Zumino-Witten anomaly. Availability of nonlocality not change a value of transition form factor in chiral limit. On the physical threshold of reaction, the transition form factor F3π is obtained close to the experimental data on account of current mass of quark
Deep inelastic and conversion in the NA64 experiment at the CERN SPS
We study the Lepton Flavor Violating (LFV) conversion in Deep
Inelastic Scattering (DIS) of electron (muon) on fixed-target nuclei. Our
model-independent analysis is based on the set of the low-energy effective
four-fermion LFV operators composed of leptons and quarks with the
corresponding mass scales for each operator. Using the estimated
sensitivity of the search for this LFV process in events with large missing
energy in the NA64 experiment at the CERN SPS, we derive lower limits for
and compared them with the corresponding limits existing in the
literature. We show that the DIS conversion is able to provide a
plenty of new limits as yet non-existing in the literature. We also analyzed
the energy spectrum of the final-state and discussed viability of the
observation of this process in the NA64 experiment and ones akin to it. The
case of polarized beams and targets is also discussed.Comment: 18 page
Free Malcev algebra of rank three
We find a basis of the free Malcev algebra on three free generators over a
field of characteristic zero. The specialty and semiprimity of this algebra are
proved. In addition, we prove the decomposability of this algebra into
subdirect sum of the free Lie algebra rank three and the free algebra of rank
three of variety of Malcev algebras generated by a simple seven-dimensional
Malcev algebra
Intrinsic multipole moments of non-Gaussian wave packets
The charged wave packets with non-Gaussian spatial profiles are shown to possess intrinsic multipole moments. The magnetic dipole moment and the electric quadrupole moment are found for a wide class of the packets, including the vortex electrons with orbital angular momentum ℓ, the Airy beams, the so-called Schrödinger's cat states, and their generalizations. For the packets with no phase vortices, the electric quadrupole moment is shown to grow quadratically with the packet's width, |Qαβ|∼e⋅σ2⊥, while it is also |ℓ| times enhanced for the vortex beams. For available beams of electron microscopes, these multipole moments are relatively easily adjusted and can be quite large, which affects the packets' electromagnetic fields and also allows one to develop new diagnostic tools for materials science, atomic and molecular physics, nuclear physics, and so forth
Bicrossproduct Hopf quasigroups
We recall the notion of Hopf quasigroups introduced previously. We construct
a bicrossproduct Hopf quasigroup kM\bicross k(G) from every group with a
finite subgroup and IP quasigroup transversal subject
to certain conditions. We identify the octonions quasigroup as
transversal in an order 128 group with subgroup and hence obtain a
Hopf quasigroup kG_O\lcocross k(Z_2^3) as a particular case of our
construction.Comment: 16 pages latex no figure
- …