Nuclear transparencies in relativistic A(e,e'p) models

Relativistic and unfactorized calculations for the nuclear transparency extracted from exclusive A(e,e'p) reactions for 0.3 \leq Q^2 \leq 10 (GeV/c)^2 are presented for the target nuclei C, Si, Fe and Pb. For Q^2 \geq 0.6 (GeV/c)^2, the transparency results are computed within the framework of the recently developed relativistic multiple-scattering Glauber approximation (RMSGA). The target-mass and Q^2 dependence of the RMSGA predictions are compared with relativistic distorted-wave impulse approximation (RDWIA) calculations. Despite the very different model assumptions underlying the treatment of the final-state interactions in the RMSGA and RDWIA frameworks, they predict comparable nuclear transparencies for kinematic regimes where both models are applicable.Comment: 15 pages, 4 figure

Pre-storage nitric oxide treatment enhances chilling tolerance of zucchini fruit (Cucurbita pepo L.) by S-nitrosylation of proteins and modulation of the antioxidant response

Nitric oxide (NO), a major signalling molecule with various physiological functions in plants, participates in many responses to abiotic disorders such as cold stress. Chilling injury (CI) is the most costly postharvest problem in zucchini fruit (Cucurbita pepo L.), since it diminishes market acceptability and shelf life. This study investigates the effect of NO treatment on zucchini fruit during postharvest cold storage. Fruit were dipped in an aqueous solution of sodium nitroprusside (SNP; 25, 100, and 500 μM) as a NO donor and in potassium ferricyanide (a structural analogue of SNP) and distilled water, both used as controls and responding the same during postharvest cold storage. The results showed that the application of 25 μM SNP treatment reduced weight loss and CI in zucchini fruit during cold storage. S-nitrosylated proteins detected in the exocarp of NO-treated fruit were more abundant than in non-treated fruit. The application of SNP improved the quality of zucchini fruit stored at 4 °C, with a reduction of weight loss, electrolyte leakage, content of malondialdehyde and HO, and delayed loss of firmness during cold storage. NO-treated fruit showed a higher activity of superoxide dismutase, ascorbate peroxidase, glutathione reductase, and phenylalanine ammonia lyase during the first days of cold storage. Total antioxidant capacity was higher in the NO-treated fruit during the first days of cold storage, supported also by higher concentrations of phenols. NO appeared to play a regulatory role in the antioxidant balance in zucchini fruit, maintaining the cellular redox homeostasis and thus modulating ROS toxicity, thereby improving fruit quality during cold conservation.This research has been funded by the Ministerio de Economía y Competitividad and Fondo Europeo de Desarrollo Regional FEDER (Project AGL2014-54598-C2-R) and the Ministerio de Ciencia, Innovacion y Universidades (Project AGL2017-82885-C2-2-R). Alejandro Castro Cegrí and Raquel Jim´enez Munoz ˜ were supported by FPI Grants (MEC

Measurement of the E**2(T,jet) / Q**2 dependence of forward jet production at HERA

The forward-jet cross section in deep inelastic ep scattering has been measured using the ZEUS detector at HERA with an integrated luminosity of 6.36 pb^-1. The jet cross section is presented as a function of jet transverse energy squared, E(T,jet)^2, and Q^2 in the kinematic ranges 10^-2<E(T,jet)^2/Q^2<10^2 and 2.5 10^-4<x<8.0 10^-2. Since the perturbative QCD predictions for this cross section are sensitive to the treatment of the log(E_T/Q)^2 terms, this measurement provides an important test. The measured cross section is compared to the predictions of a next-to-leading order pQCD calculation as well as to various leading-order Monte Carlo models. Whereas the predictions of all models agree with the measured cross section in the region of small E(T,Jet)^2/Q^2, only one model, which includes a resolved photon component, describes the data over the whole kinematic range.Comment: 8 pages including 3 figure

Measurement of the diffractive cross section in deep inelastic scattering using ZEUS 1994 data

The DIS diffractive cross section, dσdiffγ*p→XN/dMx, has been measured in the mass range Mx < 15 GeV for γ*p c.m. energies 60 < W < 200 GeV and photon virtualities Q2 = 7 to 140 GeV2. For fixed Q2 and Mx, the diffractive cross section rises rapidly with W, dσdiffγ*p→X N (Mx, W, Q2)/dMx ∝ Wadiff with adiff = 0.507 ± 0.034 (stat) +0.155-0.046 (syst) corresponding to a t-averaged pomeron trajectory of ̄αℙ = 1.127 ± 0.009 (stat) +0.039-0.012 (syst) which is larger than ̄αℙ observed in hadron-hadron scattering. The W dependence of the diffractive cross section is found to be the same as that of the total cross section for scattering of virtual photons on protons. The data are consistent with the assumption that the diffractive structure function FD(3)2 factorizes according to cursive greek chiℙFD(3)2(cursive greek chiℙ, β, Q2) = (cursive greek chi0//cursive greek chiℙ)nFD(2)2(β, Q2). They are also consistent with QCD based models which incorporate factorization breaking. The rise of cursive greek chiℙFD(3)2 with decreasing cursive greek chiℙ and the weak dependence of FD(2)2 on Q2 suggest a substantial contribution from partonic interactions