401 research outputs found

    Relativistic effects and two-body currents in 2H(e⃗,eâ€Čp)n^{2}H(\vec{e},e^{\prime}p)n using out-of-plane detection

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    Measurements of the 2H(e⃗,eâ€Čp)n{^2}H(\vec{e},e^{\prime}p)n reaction were performed using an 800-MeV polarized electron beam at the MIT-Bates Linear Accelerator and with the out-of-plane magnetic spectrometers (OOPS). The longitudinal-transverse, fLTf_{LT} and fLTâ€Čf_{LT}^{\prime}, and the transverse-transverse, fTTf_{TT}, interference responses at a missing momentum of 210 MeV/c were simultaneously extracted in the dip region at Q2^2=0.15 (GeV/c)2^2. On comparison to models of deuteron electrodisintegration, the data clearly reveal strong effects of relativity and final-state interactions, and the importance of the two-body meson-exchange currents and isobar configurations. We demonstrate that these effects can be disentangled and studied by extracting the interference response functions using the novel out-of-plane technique.Comment: 4 pages, 4 figures, and submitted to PRL for publicatio

    A Measurement of the Interference Structure Function, R_LT, for the 12C(e,e'p) reaction in the Quasielastic Region

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    The coincidence cross-section and the interference structure function, R_LT, were measured for the 12C(e,e'p) 11B reaction at quasielastic kinematics and central momentum transfer of q=400 MeV/c. The measurement was at an opening angle of theta_pq=11 degrees, covering a range in missing energy of E_m = 0 to 65 MeV. The R_LT structure function is found to be consistent with zero for E_m > 50 MeV, confirming an earlier study which indicated that R_L vanishes in this region. The integrated strengths of the p- and s-shell are compared with a Distorted Wave Impulse Approximation calculation. The s-shell strength and shape are compared with a Hartree Fock-Random Phase Approximation calculation. The DWIA calculation overestimates the cross sections for p- and s-shell proton knockout as expected, but surprisingly agrees with the extracted R_LT value for both shells. The HF-RPA calculation describes the data more consistently, which may be due to the inclusion of 2-body currents in this calculation.Comment: 8 Pages LaTex, 5 postscript figures. Submitted to Phys. Rev.

    Dysregulation of NF–Y splicing drives metabolic rewiring and aggressiveness in colon cancer

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    NF-Y is an evolutionarily conserved transcription factor that binds specifically to the CCAAT elements of eukaryotic genes, most of which frequently deregulated in cancer. NF-YA, the regulatory subunit of the NF-Y complex, has two isoforms generated by alternative splicing, NF-YAl and NF-YAs, which differ in the transactivation domain. Transcriptomic data from The Cancer Genome Atlas (TCGA) database highlighted a significant increase in the expression of NF-YAs at the expense of NF-YAl in colorectal cancer (CRC), compared to healthy tissues. Despite this, high NF-YAl levels predict lower patients’ survival and distinguish the mesenchymal molecular subtype CMS4, which is characterized by the worst prognosis. Through the analysis of 3D cellular models, we demonstrated that altered expression of genes related to extracellular matrix and epithelial-mesenchymal transition sustains enhanced migratory and invasive behavior of NF-YAl-transduced cells. Moreover, the integration of metabolomics, bioenergetics and transcriptional analyses demonstrated a direct role for NFYAl in metabolic flexibility of cancer cells that adjust their metabolism in response to environmental changes to potentiate migration. The zebrafish xenograft model confirmed the metastatic potential triggered by NF-YAl in CRC cells. Altogether, our data highlight the transcriptional role of NF-YAl in CRC aggressiveness and suggest splice-switching strategies to hinder NF-YAl-induced metastatic dissemination

    Search for anomalies in the {\nu}e appearance from a {\nu}{\mu} beam

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    We report an updated result from the ICARUS experiment on the search for {\nu}{\mu} ->{\nu}e anomalies with the CNGS beam, produced at CERN with an average energy of 20 GeV and travelling 730 km to the Gran Sasso Laboratory. The present analysis is based on a total sample of 1995 events of CNGS neutrino interactions, which corresponds to an almost doubled sample with respect to the previously published result. Four clear {\nu}e events have been visually identified over the full sample, compared with an expectation of 6.4 +- 0.9 events from conventional sources. The result is compatible with the absence of additional anomalous contributions. At 90% and 99% confidence levels the limits to possible oscillated events are 3.7 and 8.3 respectively. The corresponding limit to oscillation probability becomes consequently 3.4 x 10-3 and 7.6 x 10-3 respectively. The present result confirms, with an improved sensitivity, the early result already published by the ICARUS collaboration

    Precise 3D track reconstruction algorithm for the ICARUS T600 liquid argon time projection chamber detector

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    Liquid Argon Time Projection Chamber (LAr TPC) detectors offer charged particle imaging capability with remarkable spatial resolution. Precise event reconstruction procedures are critical in order to fully exploit the potential of this technology. In this paper we present a new, general approach of three-dimensional reconstruction for the LAr TPC with a practical application to track reconstruction. The efficiency of the method is evaluated on a sample of simulated tracks. We present also the application of the method to the analysis of real data tracks collected during the ICARUS T600 detector operation with the CNGS neutrino beam.Comment: Submitted to Advances in High Energy Physic

    Tensor Analyzing Powers for Quasi-Elastic Electron Scattering from Deuterium

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    We report on a first measurement of tensor analyzing powers in quasi-elastic electron-deuteron scattering at an average three-momentum transfer of 1.7 fm−1^{-1}. Data sensitive to the spin-dependent nucleon density in the deuteron were obtained for missing momenta up to 150 MeV/cc with a tensor polarized 2^2H target internal to an electron storage ring. The data are well described by a calculation that includes the effects of final-state interaction, meson-exchange and isobar currents, and leading-order relativistic contributions.Comment: 4 pages, 3 figure

    Electromagnetic Meson Production in the Nucleon Resonance Region

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    Recent experimental and theoretical advances in investigating electromagnetic meson production reactions in the nucleon resonance region are reviewed.Comment: 75 pages, 42 figure

    Experimental search for the LSND anomaly with the ICARUS detector in the CNGS neutrino beam

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    We report an early result from the ICARUS experiment on the search for nu_mu to nu_e signal due to the LSND anomaly. The search was performed with the ICARUS T600 detector located at the Gran Sasso Laboratory, receiving CNGS neutrinos from CERN at an average energy of about 20 GeV, after a flight path of about 730 km. The LSND anomaly would manifest as an excess of nu_e events, characterized by a fast energy oscillation averaging approximately to sin^2(1.27 Dm^2_new L/ E_nu) = 1/2. The present analysis is based on 1091 neutrino events, which are about 50% of the ICARUS data collected in 2010-2011. Two clear nu_e events have been found, compared with the expectation of 3.7 +/- 0.6 events from conventional sources. Within the range of our observations, this result is compatible with the absence of a LSND anomaly. At 90% and 99% confidence levels the limits of 3.4 and 7.3 events corresponding to oscillation probabilities of 5.4 10^-3 and 1.1 10^-2 are set respectively. The result strongly limits the window of open options for the LSND anomaly to a narrow region around (Dm^2, sin^2(2 theta))_new = (0.5 eV^2, 0.005), where there is an overall agreement (90% CL) between the present ICARUS limit, the published limits of KARMEN and the published positive signals of LSND and MiniBooNE Collaborations.Comment: 10 pages, 7 figure
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