119540272
Self-induced spectral splits in supernova neutrino fluxes
In the dense-neutrino region above the neutrino sphere of a supernova (r < or approx. 400 km), neutrino-neutrino refraction causes collective flavor transformations. They can lead to 'spectral splits' where an energy E{sub split} splits the transformed spectrum sharply into parts of almost pure but different flavors. Unless there is an ordinary MSW resonance in the dense-neutrino region, E{sub split} is determined by flavor-lepton number conservation alone. Spectral splits are created by an adiabatic transition between regions of large and small neutrino density. We solve the equations of motion in the adiabatic limit explicitly and provide analytic expressions for a generic example.
125260667
SLIDING SINGLET AND STABILITY OF THE MASS HIERARCHY. (IN RUSSIAN)
118160727
Neutrino Oscillations In Matter With Varying Density
An alkali-metal benzoate is prepared besides benzyl alcohol from a contaminated benzyl benzoate reaction residue obtained in the oxidation of a monoalkyl-benzene compound with a gas containing molecular oxygen. The disclosed process provides for distillation of the contaminated benzyl benzoate in the presence of a basic substance and the resulting distillate is hydrolyzed using an alkali-metal base. In this way, the benzyl benzoate that previously could not be separated from certain tar components by distillation is converted into a pure alkali metal benzoate such as sodium benzoate, besides pure benzyl alcohol, so that a waste product that was previously useless is converted into useful substances.
59164737
Recent developments in neutrino phenomenology
The first phase of studies of the neutrino mass and mixing is essentially over. The outcome is the discovery of non-zero neutrino mass and determination of the dominant structure of the lepton mixing matrix. In some sense this phase was very simple, and nature was very collaborative with us: Two main effects - the vacuum oscillations and the adiabatic conversion in matter (the MSW-effect) - provide complete interpretation of the experimental results. Furthermore, with the present accuracy of measurements the $3\nu-$mixing analysis is essentially reduced to the $2\nu$ consideration. I will present a concise and comprehensive description of this first phase. The topics include: (i) the concept of neutrino mixing in vacuum and matter; (ii) physics of the oscillations and adiabatic conversion; (iii) the experimental evidences of the flavor transformations and determination of the oscillation parameters. Some implications of the obtained results are discussed. Comments are given on the next phase of the field that will be much more involved.
18492548
Pontecorvo's original oscillations revisited
Abstract We show that a left-handed neutrino ν L can oscillate into its CPT -conjugate state ν R with maximal amplitude, in direct analogy with K 0 − K 0 oscillations. Peculiarities of such oscillations under different conditions are studied.
119449106
Spin-flavor conversion and time variations of solar neutrino signals
Time variations of solarve-flux induced by spin-flavor conversion in the magnetic field of the sun have been studied. Several models of spatial and temporal distributions of the magnetic fields have been considered. The observed variations of the Ar-production rate in the Cl−Ar-experiment are shown to be not reproducible by these models. Unnaturally large values and fine tuned spatial structure of the fields are needed to explain the data.
119320601
The Number of Master Integrals is Finite
For a fixed Feynman graph one can consider Feynman integrals with all possible powers of propagators and try to reduce them, by linear relations, to a finite subset of integrals, the so-called master integrals. Up to now, there are numerous examples of reduction procedures resulting in a finite number of master integrals for various families of Feynman integrals. However, up to now it was just an empirical fact that the reduction procedure results in a finite number of irreducible integrals. It this paper we prove that the number of master integrals is always finite.
118529983
ON MASS LIMIT FOR CHIRAL COLOR SYMMETRY G'-BOSON FROM TEVATRON DATA ON $t\bar t$ PRODUCTION
The contributions of G'-boson predicted by the chiral color symmetry of quarks to the cross section $\sigma_{t\bar{t}}$ and to the forward–backward asymmetry $A_{{\rm FB}}^{p \bar p}$ of $t\bar{t}$ production at the Tevatron are calculated with account of the difference of the strengths of the $\bar q q G$ and $\bar q q G^\prime$ interactions. The results are analyzed in dependence on two free parameters of the model, the mixing angle θG and G' mass mG'. The G'-boson contributions to $\sigma_{t\bar{t}}$ and $A_{{\rm FB}}^{p \bar p}$ are shown to be consistent with the Tevatron data on $\sigma_{t\bar{t}}$ and $A_{{\rm FB}}^{p \bar p}$, the allowed region in the mG' - θG plane is discussed and around mG' = 1.2 TeV, θG = 14° the region of 1σ consistency is found.
14611410
Four Loop Massless Propagators: a Numerical Evaluation of All Master Integrals
Abstract We present numerical results which are needed to evaluate all non-trivial master integrals for four-loop massless propagators, confirming the recent analytic results of Baikov and Chetyrkin (2010) [1] and evaluating an extra order in e expansion for each master integral.
15948639
S-bases as a tool to solve reduction problems for Feynman integrals
We suggest a mathematical definition of the notion of master integrals and present a brief review of algorithmic methods to solve reduction problems for Feynman integrals based on integration by parts relations. In particular, we discuss a recently suggested reduction algorithm which uses Grobner bases. New results obtained with its help for a family of three-loop Feynman integrals are outlined.
15376747
ON A POSSIBLE MANIFESTATION OF THE FOUR-COLOR SYMMETRY Z' BOSON IN μ+μ- EVENTS AT THE LHC
The cross section of the μ+μ- pair production in pp-collisions at the LHC is calculated with account of the Z' boson induced by the minimal four-color quark–lepton symmetry (MQLS). The μ+μ- invariant mass spectrum with account of the MQLS Z' boson is analyzed in dependence on the Z' mass. The mass region for the MQLS Z' boson observable at the LHC is found in dependence on the significance and on the integrated luminosity.