54022118
Phenomenology of maximal and near maximal lepton mixing
ueu,0.3. We show that both probabilities and observables depend on e quadratically when effects are due to vacuum oscillations and they depend on e linearly if matter effects dominate. The most important information on n e mixing comes from solar neutrino experiments. We find that the global analysis of solar neutrino data allows maximal mixing with confidence level better than 99% for 10 28 eV 2 D4s ~99.995% CL! We suggest ways to measure e in future experiments. The observable that is most sensitive to e is the rate @NC#/@CC# in combination with the day-night asymmetry in the SNO detector. With theoretical and statistical uncertainties, the expected accuracy after 5 years is De;0.07. We also discuss the effects of maximal and near-maximal n e mixing in atmospheric neutrinos, supernova neutrinos, and neutrinoless double beta decay.
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.
31519375
Multiple spectral splits of supernova neutrinos.
Collective oscillations of supernova neutrinos swap the spectra f(nu(e))(E) and f(nu[over ](e))(E) with those of another flavor in certain energy intervals bounded by sharp spectral splits. This phenomenon is far more general than previously appreciated: typically one finds one or more swaps and accompanying splits in the nu and nu[over ] channels for both inverted and normal neutrino mass hierarchies. Depending on an instability condition, swaps develop around spectral crossings (energies where f(nu(e))=f(nu(x)), f(nu[over ](e))=f(nu[over ](x)) as well as E-->infinity where all fluxes vanish), and the widths of swaps are determined by the spectra and fluxes. Washout by multiangle decoherence varies across the spectrum and splits can survive as sharp spectral features.
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.
115887973
Solar neutrinos: Theoretical aspects
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.
17035129
CHIRAL COLOR SYMMETRY AND POSSIBLE G′-BOSON EFFECTS AT THE TEVATRON AND LHC
A gauge model with chiral color symmetry is considered and possible effects of the color G′-boson octet predicted by this symmetry are investigated in dependence on two free parameters, the mixing angle θG and G′ mass mG′. The allowed region in the mG'–θG plane is found from the Tevatron data on the cross section and forward–backward asymmetry of the production. The mass limits for the G′-boson are shown to be stronger than those for the axigluon. A possible effect of the G′-boson on the production at the LHC is discussed and the mass limits providing for the G′-boson evidence at the LHC are estimated in dependence on θG.
41885673
Quark and gluon form factors to three loops.
We compute the form factors of the photon-quark-anti-quark vertex and the effective vertex of a Higgs-boson and two gluons to three-loop order within massless perturbative quantum chromodynamics. These results provide building blocks for many third-order cross sections. Furthermore, this is the first calculation of complete three-loop vertex corrections.
35773955
Three-loop static potential.
We compute the three-loop corrections to the potential of two heavy quarks. In particular, we consider in this Letter the purely gluonic contribution which provides, in combination with our previous fermion corrections, the complete answer at three loops.
120793699
Quark masses from low-energy moments of heavy-quark current correlators
We present an update of the determination of charm- and bottom-quark masses from the lowenergy expansion of the vacuum polarization function in combination with experimental data for R(s). This analysis leads to the most precise determination of th e masses of the charm and bottom quarks: mc(3 GeV) = 986(13) MeV, mb(mb) = 4163(16) MeV.
118565164
Cross Section and Forward-Backward Asymmetry of $t\bar{t}$ Production in the Model with Four Color Symmetry
The contributions to the cross section $\sigma_{t\bar{t}}$ and to the forward-backward asymmetry $A_{\rm FB}^{t \bar t}$ of $t\bar{t}$ production at the Tevatron from $Z'$-boson and scalar leptoquarks $S^{(\pm)}_a$ and scalar gluons $F_a$ predicted by the minimal model with four color quark-lepton symmetry are calculated. These contributions are shown to be small in tree approximation and can be significant with account of the 1-loop $gt\bar{t}$ effective vertex induced by the scalar doublets. The lower mass limit for scalar gluons $m_F \gtrsim 320\, GeV$ from the Tevatron data is obtained and it is shown that for $m_{F_1}\lesssim 990\,GeV$ the scalar gluon $F_1$ can be evident at LHC at the significance not less that $3\sigma$ (for $\sqrt{s}=14$ TeV, $L=10\,fb^{-1}$).