Neutrino energy reconstruction from one muon and one proton events

We propose a new method of selection of high purity charge current quasielastic neutrino events with a good reconstruction of interacting neutrino energy. Performance of the method was verified with several tests using GENIE, NEUT and NuWro Monte Carlo events generators with carbon and argon targets. The method can be useful in neutrino oscillation studies with a few GeV energy beams.Comment: 8 pages, 5 figure

A Note on W Production at HERA

We discuss W boson production at HERA including NLO QCD corrections.Comment: 2 pages, latex, 2 figures, Contribution to the 3rd UK Phenomenology Workshop on HERA Physics, Durham, 20-25 Sep. 199

Numerical Implementation of lepton-nucleus interactions and its effect on neutrino oscillation analysis

We discuss the implementation of the nuclear model based on realistic nuclear spectral functions in the GENIE neutrino interaction generator. Besides improving on the Fermi gas description of the nuclear ground state, our scheme involves a new prescription for $Q^2$ selection, meant to efficiently enforce energy momentum conservation. The results of our simulations, validated through comparison to electron scattering data, have been obtained for a variety of target nuclei, ranging from carbon to argon, and cover the kinematical region in which quasi elastic scattering is the dominant reaction mechanism. We also analyse the influence of the adopted nuclear model on the determination of neutrino oscillation parameters.Comment: 19 pages, 35 figures, version accepted by Phys. Rev.

Charged-current Quasi-elastic-like neutrino interactions at the T2K experiment

T2K is a long-baseline neutrino oscillation experiment based in Japan. The experiment has already measured the appearance of ⌫e in a ⌫μ beam, and is hoping to measure the appearance of ⌫¯e in a ⌫¯μ beam, which would open the possibility of observing CP-violation in the lepton sector. The charged current quasi-elastic (CCQE) interaction (vμ + n -> μ− + p) is of great importance to T2K as it is expected to make up over 80% of the interactions at the oscillation peak (600 MeV). In recent years it has become clear that the most common model describing CCQE interactions on nuclei, the Relativistic Fermi Gas (RFG) model, is not able to describe low energy data on nuclear targets. An alternative model, the Spectral Function (SF) model, was implemented in the NEUT interaction generator. Relevant uncertainties in this model are identified and evaluated. The charged current quasi-elastic-like cross section is then measured using the T2K near detector, ND280, as a function of muon momentum and angle. This data is then critically compared to the predictions from two implementations of the RFG model, and also to the newly implemented SF model. The total integrated cross section is found to be (4.06 ± 0.757) x 10−39 cm2 nucleon−1. This value is currently in agreement with all three predictions

Multiple molecular forms of human lactoferrin. Identification of a class of lactoferrins that possess ribonuclease activity and lack iron-binding capacity

Lactoferrin (Lf), the major iron-binding component of milk, also a major constituent of the specific granules of neutrophils involved in antimicrobial activity and a glycoprotein thought to play a role in regulatory functions in the hematopoietic system as well as other physiologic activities, is shown to occur in three isoforms. One, Lf-alpha, binds iron; the other two, Lf-beta and Lf-gamma, express potent RNase activity, but do not bind iron. The three isoforms are very similar or identical in Mr, pI, partial proteolytic peptide patterns, NH2-terminal amino acid sequence, and reactivity with mAbs and polyclonal antisera against the RNase and Lf, respectively. The finding of structurally similar but enzymatically distinct forms of Lf may be related to the diverse functions of the molecule

Canonical Quantisation in n.A=0 gauges

We give a unified derivation of the propagator in the gauges $n.A=0$ for $n^2$ timelike, spacelike or lightlike. We discuss the physical states and other physical questions.Comment: 7 pages, DAMTP 93-33, ITP-SB-93-3

Strong Coupling Constant from Scaling Violations in Fragmentation Functions

We present a new determination of the strong coupling constant alpha_s through the scaling violations in the fragmentation functions for charged pions, charged kaons, and protons. In our fit we include the latest e+e- annihilation data from CERN LEP1 and SLAC SLC on the Z-boson resonance and older, yet very precise data from SLAC PEP at center-of-mass energy sqrt(s)=29 GeV. A new world average of alpha_s is given.Comment: 10 pages, 3 eps figue

Pion and Kaon Production in e+e−e^+e^- and epep Collisions at Next-to-Leading Order

We present new sets of fragmentation functions for charged pions and kaons, both at leading and next-to-leading order. They are fitted to data on inclusive charged-hadron production in $e^+e^-$ annihilation taken by TPC at PEP ($\sqrt s=29$~GeV) and to similar data by ALEPH at LEP, who discriminated between events with charm, bottom, and light- flavour fragmentation in their charged-hadron sample. We treat all partons independently and to properly incorporate the charm and bottom thresholds. Due to the sizeable energy gap between PEP and LEP, we are sensitive to the scaling violation in the fragmentation process, which allows us to extract a value for the asymptotic scale parameter of QCD, $\Lambda$. Recent data on inclusive charged-hadron production in tagged three-jet events by OPAL and similar data for longitudinal electron polarization by ALEPH allow us to pin down the gluon fragmentation functions. Our new fragmentation functions lead to an excellent description of a multitude of other $e^+e^-$ data on inclusive charged-hadron production, ranging from $\sqrt s=5.2$~GeV to LEP energy. In addition, they agree nicely with the transverse-momentum spectra of single charged hadrons measured by H1 and ZEUS in photoproduction at the $ep$ collider HERA, which represents a nontrivial check of the factorization theorem of the QCD-improved parton model.Comment: 22 pages, latex, 13 compressed ps figures in separate fil