Overview of progress in neutrino scattering measurements

Recent progress in neutrino scattering experiments with few GeV neutrino beams is reviewed, focusing on new experimental input since the beginning of the NuInt workshop series in 2001. Progress in neutrino quasi-elastic scattering, resonance production, coherent pion production, scattering in the transition region between the resonance and deep inelastic regimes, and nuclear effects in neutrino-nucleus scattering, is discussed.Comment: To appear in the proceedings of 5th International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Batavia, Illinois, 30 May - 3 Jun 2007. Submitted to AIP Conf.Pro

Coherent Pion Production by Neutrinos

I concentrate in this article on the reaction--coherent pion production by neutrinos incident on nuclei. A special effort is made in order to describe the approximations entering the calculation. I conclude that the reaction is well understood and with appropriate data for hadronic reactions is can be computed for low and high energies. Because of shortage of space I omitted the resonance analysis, which is described in articles with my collaborators.Comment: 4 pages. Proceedings of Conf. to be published by APS-Proceeding

Why understanding neutrino interactions is important for oscillation physics

Uncertainties in knowledge of neutrino interactions directly impact the ability to measure the parameters of neutrino oscillation. Experiments which make use of differing technologies and neutrino beams are sensitive to different uncertainties. Several experimental and theoretical issues are reviewed.Comment: Proceedings prepared for the Fifth International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), May 30-June 2, 2007. Proceedings to be published by the AIP (6 pages

Understanding the Forward Muon Deficit in Coherent Pion Production

For any inelastic process $v_{\ell} + I \to \ell^- + F$ with $m_{\ell} = 0$, the cross section at $\theta_{\ell} = 0$ is given by Adler's PCAC theorem. Inclusion of the lepton mass has a dynamical effect (``PCAC-screening'') caused by interference of spin-zero ($\pi^+$) and spin-one exchanges. This effect may be relevant to the forward suppression reported in recent experiments.Comment: 3 pages, 2 figures, presented at NuInt07, Fermilab, may 31 - june 3 200

Charged-Current Interaction Measurements in MiniBooNE

Neutrino oscillation is the only known phenomenon for physics beyond the standard model. To investigate this phenomenon, the understanding of low energy neutrino scattering (200<E<2000 MeV) is the crucial task for high energy physicists. In this energy region, the charged current quasi-elastic (CCQE) neutrino interaction is the dominant process, and experiments require a precise model to predict signal samples. Using a high-statistics sample of muon neutrino CCQE events, MiniBooNE finds that a simple Fermi gas model, with appropriate adjustments, accurately characterizes the CCQE events on carbon. The extracted parameters include an effective axial mass, MA=1.23 +- 0.20 GeV, and a Pauli-blocking parameter, kappa = 1.019 +- 0.011.Comment: Proceedings of the 5th International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07

Single Pion Measurement Capabilities at SciBooNE

The precise knowledge of the single pion production cross-section of neutrino around the ~1 GeV energy region is an essential ingredient in the interpretation of neutrino oscillation experiments. The unique opportunities and prospects of single pion measurements at SciBooNE are described.Comment: Proceedings of the 5th International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Batavia, Illinois, 30 May - 3 Jun 200

Neutral Current π0\pi^0 Production in MiniBooNE

This paper describes the analysis used to determine the neutral current $\pi^0$ production in MiniBooNE in bins of momentum. Additionally, a measurement of the relative coherent production of $\pi^0$s is discussed. The coherent production rate is found to be (19.5 $\pm$1.1 (stat) $\pm$2.5 (sys))% of the total exclusive neutral current $\pi^0$ production rate.Comment: Prepared for the Proceedings of Neutrino Interactions 200

NC pi0 Production in the MiniBooNE Antineutrino Data

The single largest background to future numubar to nuebar (numu to nue) oscillation searches is neutral current pi0 production. MiniBooNE, which began taking antineutrino data in January 2006, has the world's largest sample of pi0's produced by antineutrinos in the 1 GeV energy range. These neutral pions are primarily produced through the delta resonance but can also be created through "coherent production." The latter process is the coherent sum of glancing scatters of (anti)neutrinos off a neutron or proton, in which the nucleus is kept intact but a pi0 is created. Current analysis of NC pi0 production in the MiniBooNE antineutrino data will be discussed.Comment: 4 pages, including 5 figures. Proceedings of the 5th International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Batavia, Illinois, 30 May - 3 Jun 200

Modeling Lepton-Nucleon Inelastic Scattering from High to Low Momentum Transfer

We present a model for inclusive charged lepton-nucleon and (anti)neutrino-nucleon cross sections at momentum transfer squared, $Q^2$, $\sim1 {\rm GeV}^2$. We quantify the impact of existing low-Q charged-lepton deep-inelastic scattering (DIS) data on effects due to high-twist operators and on the extraction of parton distribution functions (PDFs). No evidence is found for twist-6 contributions to structure functions (SF), and for a twist-4 term in the logitudinal SF at $x\gtrsim0.1$. We find that DIS data are consistent with the NNLO QCD approximation with the target mass and phenomenological high twist corrections. For $Q^2<1 {\rm GeV}^2$, we extend extrapolation of the operator product expansion, preserving the low-$Q$ current-conservation theorems. The procedure yields a good description of data down to $Q^2\sim 0.5 {\rm GeV}^2$. An updated set of PDFs with reduced uncertainty and applicable down to small momentum transfers in the lepton-nucleon scattering is obtained.Comment: 10 pages, 6 figures, proceedings of the 5th International Workshop on Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Batavia, Illinois, 30 May - 3 Jun 200