Elastic neutrino proton scattering and the structure of the neutral current

Optimal constraints on the structure of a general V, A hadronic neutral current are derived from neutrino proton scattering and compared with corresponding results from inclusive neutrino scattering and single pion production by neutrinos. For an arbitrary axial component of the neutral current, restrictions for the vector coupling constants are obtained. It is shown that the most general neutral current which can be related to charged weak and electromagnetic currents accounts for all existing data on neutrino hadron scattering. The neutral current coupling constants are determined for the pure isovector model, the Salam-Weinberg model and the bottom-quark model. All three models lead to practically the same isovector couplings but they differ in the strength of the isoscalar current.     

Unitarity corrections to kaon-pion scattering from current algebra

A method is presented to unitarize the hard-meson current algebra kaon-pion amplitude derived by Ford. Elastic unitarity is satisfied in the lowest-order correction to current algebra. The amplitude contains? three real parameters and does not have any arbitrary function for simulating left-hand discontinuities. Once the isospin-half P-wave is given in the low-energy region, this method leads to a sharp determination of the S-wave phase shifts. Our solution favors the “down” type for the $\text{I =}\text{1}\text{2}$ S-wave phase shifts.     

Recovering partial conservation of axial current in diffractive neutrino scattering

A model of diffractive neutrino scattering is formulated in terms of the chiral hadronic current which is conserved in the limit of vanishing pion mass. This current has the correct singularity structure and, naturally, does not lead to contradictions with a partial conservation of the axial current (PCAC). In that respect we differ from earlier work in the literature, where a breakdown of PCAC had been reported. We show that such a breakdown of PCAC is an artifact of the hadronic current non-conservation in the model developed there.     

Superscaling in charged current neutrino quasielastic scattering in the relativistic impulse approximation

Superscaling of the quasielastic cross section in charged-current neutrino-nucleus reactions at energies of a few GeV is investigated within the framework of the relativistic impulse approximation. Several approaches are used to describe final-state interactions and comparisons are made with the plane-wave approximation. Superscaling is very successful in all cases. The scaling function obtained using a relativistic mean field for the final states shows an asymmetric shape with a long tail extending towards positive values of the scaling variable, in excellent agreement with the behavior presented by the experimental scaling function.     

Transverse enhancement model and MiniBooNE charge current quasi-elastic neutrino scattering data

Recently proposed Transverse Enhancement Model of nuclear effects in Charge Current Quasi-Elastic neutrino scattering (A. Bodek, H.S. Budd, M.E. Christy, Eur. Phys. J. C 71:1726, 2011) is confronted with the MiniBooNE high statistics experimental data.     

States on the current algebra

We introduce the field algebra Σ$\text{D}$(M;ⁿ?ⁿ$\text{g}$) associated with the current algebra $\text{D}$_r(M;$\text{g}$) for the Lie algebra $\text{g}$ over physical space M. The Heisenberg magnet model is generalized to this continuum. It is shown that the Hamiltonian can be given meaning as implementing a derivation of the field algebra in certain representations.We introduce new representations of the current algebra. For example, if G = SU(2), a representation in L²(R³)?³ is [σ(?)F]^j = ε^jkl?_kψ_l for (?_k) = ? in $\text{D}$_r(M;$\text{g}$)(ψ_l = F. This has cyclic subrepresentations with prime parts.     

Refractive index of light and the quark-gluon plasma

The refractive index (RI) of light propagating in a medium of quark-gluon plasma (QGP) is studied. The weakly coupled QGP is studied in the framework of hard-thermal-loop (HTL) perturbation theory, and the strongly coupled one is treated based on the holographic approach. In more realistic setups, the feasibility of observing the optical phenomenon related to the RI of QGP is also discussed.     

Rigorous results concerning light cone dominance in deep inelastic lepton-hadron scattering

We consider a class of distributions, appearing in electro-production and satisfying a Jost-Lehmann-Dyson representation. We then prove without further assumptions that only their singularity structure near the light cone is relevant for the behaviour of their Fourier transform in the Bjorken limit. Furthermore we study the ambiguity in this singularity structure introduced by the fact, that scaling is known only in the space like region of momentum space.Work supported by the Bundesministerium für Forschung und Technologie.     

Difficulties in detecting a T-violating charmed weak current in neutrino scattering

The dilepton signature of charm production in deep-inelastic νN scattering allows searches for leptonic correlations odd under momentum and spin reversal. Which correlations truly indicate T non-invariance is discussed. The measurable T-violating asymmetries due to typical maximal T non-invariant charmed weak currents are estimated, and found to be uncomfortably small, making tests for T violation extremely difficult.     

Magnetic neutrino scattering on atomic electrons revisited

We reexamine the role of electron binding effects in the inelastic neutrino–atom scattering induced by the neutrino magnetic moment. The differential cross section of the process is presented as a sum of the longitudinal and transverse components, according to whether the force that the neutrino magnetic moment exerts on electrons is parallel or perpendicular to momentum transfer. The atomic electrons are treated nonrelativistically. On this basis, the recent theoretical predictions concerning the magnetic neutrino-impact ionization of atoms are critically discussed. Numerical calculations are performed for ionization of a hydrogenlike Ge⁺³¹ ion by neutrino impact.     

Supernova neutrino nucleosynthesis of light elements with neutrino oscillations

Light element synthesis in supernovae through neutrino-nucleus interactions, i.e., the v process, is affected by neutrino oscillations in the supernova environment. There is a resonance of 13-mixing in the O/C layer, which increases the rates of charged-current -process reactions in the outer He-rich layer. The yields of 7Li and 11B increase by about a factor of 1.9 and 1.3, respectively, for a normal mass hierarchy and an adiabatic 13-mixing resonance, compared to those without neutrino oscillations. In the case of an inverted mass hierarchy and a nonadiabatic 13-mixing resonance, the increase in the 7Li and 11B yields is much smaller. Observations of the 7Li/11B ratio in stars showing signs of supernova enrichment could thus provide a unique test of neutrino oscillations and constrain their parameters and the mass hierarchy.     

Gentle neutrino scattering and the Davis experiment

Energy loss from many very soft elastic scatterings of neutrinos could remove the energy from the neutrinos from the sun. This might be detectable through gross heating of cryogenic preparations by currently available neutrino beams.     

Charm of small-x neutrino deep-inelastic scattering

Due to the weak-current nonconservation, the diffractive excitation of the charm and strangeness dominates the longitudinal structure function F _L (x, Q ²) of a neutrino DIS at a small Bjorken x. Quantitative predictions based on the color dipole BFKL approach are given for this effect in the kinematical range of the CCFR/NuTeV experiment. The relevance of our findings to the experimental tests of PCAC is discussed. The text was submitted by the authors in English.