213 research outputs found

    Towards 1/N corrections to deep inelastic scattering from the gauge/gravity duality

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    1/N21/N^2 corrections to deep inelastic scattering (DIS) of charged leptons from glueballs at strong coupling are investigated in the framework of the gauge/gravity duality. The structure functions F1F_1 and F2F_2 (and also FLF_L) are studied at subleading order in the 1/N21/N^2 expansion, in terms of q2q^2 and the Bjorken parameter xx. The relevant type IIB supergravity one-loop diagrams (which correspond to DIS with two-hadron final states) are studied in detail, while nn-loop diagrams (corresponding to DIS with (n+1)(n+1)-hadron final states) are briefly discussed. The 1/N2n1/N^{2n} and Λ2/q2\Lambda^2/q^2 dependence of the structure functions is analyzed. Within this context two very different limits are considered: one is the large NN limit and the other one is when the virtual photon momentum transfer qq is much larger than the infrared confining scale Λ\Lambda. These limits do not commute.Comment: 45 page

    Deep inelastic scattering off scalar mesons in the 1/N expansion from the D3D7-brane system

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    Deep inelastic scattering (DIS) of charged leptons off scalar mesons in the 1/N expansion is studied by using the gauge/gravity duality. We focus on the D3D7-brane system and investigate the corresponding structure functions by considering both the high energy limit and the 1/N expansion. These limits do not commute. From the D7-brane DBI action we derive a Lagrangian at sub-leading order in the D7-brane fluctuations and obtain a number of interactions some of which become relevant for two-hadron final-state DIS. By considering first the high energy limit followed by the large N one, our results fit lattice QCD data within 1.27% for the first three moments of F 2 for the lightest pseudoscalar meson.Fil: Jorrin, David Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Kovensky, Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Schvellinger, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentin

    PoolSeq analysis of the selection of the Rhizobium genotypes by the legume host plant

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    Rhizobium leguminosarum establishes highly specific nitrogen-fixing symbioses. We have applied a Pool-Seq approach to study plant host selection of genotypes. Our results confirm, at the genomic level, previous observations regarding plant selection of specific genotype

    Populations genomics analysis of legume host preference for specific rhizobial genotypes in the Rhizobium leguminosarum bv. viciae symbioses

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    Rhizobium leguminosarum bv. viciae establishes root nodule symbioses with several legume genera. Although most isolates are equally effective in establishing symbioses with all host genera, previous evidence suggests that hosts select specific rhizobial genotypes among those present in the soil. We have used population genomics to further investigate this observation. P. sativum, L. culinaris, V. sativa, and V. faba plants were used to trap rhizobia from a well-characterized soil, and pooled genomic DNAs from one-hundred isolates from each plant were sequenced. Sequence reads were aligned to the R. leguminosarum bv. viciae 3841 reference genome. High overall conservation of sequences was observed in all subpopulations, although several multigenic regions were absent from the soil population. A large fraction (16-22%) of sequence reads could not be recruited to the reference genome, suggesting that they represent sequences specific to that particular soil population. Although highly conserved, the 16S-23S rRNA gene region presented single nucleotide polymorphisms (SNPs) regarding the reference genome, but no striking differences could be found among plant-selected subpopulations. Plant-specific SNP patterns were, however, clearly observed within the nod gene cluster, supporting the existence of a plant preference for specific rhizobial genotypes. This was also shown after genome-wide analysis of SNP patterns

    Higher-twist fermionic operators and DIS structure functions from the AdS/CFT duality

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    The role of local higher-twist (τ>3) spin-1/2 fermionic operators of the strongly coupled N=4 supersymmetric Yang-Mills theory on the symmetric and antisymmetric deep inelastic scattering structure functions is investigated. The calculations are carried out in terms of the duality between N=4 SYM theory and type IIB supergravity on AdS5×S5. Particularly, we explicitly obtain the structure functions for single-trace spin-1/2 fermionic operators in the 20∗ and 60∗ irreducible representations of SU(4)R, corresponding to twists 4 and 5, respectively. We also calculate the contributions of other single-trace spin-1/2 fermionic operators in the 4, 20 and 60 irreducible representations of SU(4)R. New important effects are found in comparison with the minimal twist (τ=3) case, and they are studied thoroughly.Fil: Jorrin, David Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Schvellinger, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; Argentin

    The Interactive Research Methods Lab: An Open Innovation

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    An open innovation model eliminates traditional barriers between practitioners, universities, and other sources of innovation, research, and development. Open innovation also eliminates boundaries inside a university, including interdisciplinary and interdepartmental ones. The Interactive Research Methods Lab team members will share a short video about the IRML submitted for the Sage Innovators Award and will answer the following questions: Why do we consider the IRML an open innovation? How does the IRML adhere to open access, educational resources, science, and source principles? View Genially. Visit IRML Homepage

    Spin-1/2 fermionic operators of n=4 SYM theory and DIS from type IIB supergravity

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    We study deep inelastic scattering (DIS) of charged leptons from polarised spin1/2 hadrons in terms of the gauge/gravity duality. We calculate the structure functions related to spin-1/2 fermionic operators of N = 4 SYM theory in the planar limit and at strong coupling. Specifically, we focus on the twist-3 operator which is dual to a certain dilatino mode and gives the leading contribution to the hadronic tensor. We consider the Bjorken variable within the parametric range λ −1/2 SYM ≪ x < 1 where the supergravity dual description holds. From dimensional reduction of type IIB supergravity on the five-sphere, we derive the interaction terms involving two dilatini and a massless vector field mode. This vector field is a linear combination of certain components of the graviton and the four-form potential. The angular integrals on the five-sphere lead to selection rules for the interactions with important consequences on the dynamics. This implies the existence of new terms contributing to the structure functions that we explicitly calculate. The leading contribution comes from the Pauli term, followed by the contributions from the new terms we found.Fil: Jorrin, David Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Michalski, Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Schvellinger, Martín Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentin

    Proton helicity structure function g_1^p from a holographic Pomeron

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    We present a detailed analysis of the polarized and the unpolarized deep inelastic scattering structure functions of the proton, g_1^p and F_2^p respectively, in the context of a holographic dual description based on type IIB superstring theory. We compare this description with experimental data and Quantum Chromodynamics estimates computed at leading, next-to-leading and next-to-next-to-leading order in perturbation. We confront the predictions of a holographic dual model and those of perturbative QCD for g_1^p at the kinematics that will be probed by the forthcoming Electron-Ion Collider. We find that the extrapolation of g_1^p to very small values the Bjorken variable computed with a Holographic Pomeron model based on actual data at higher momentum fractions is always positive and differs significantly with standard projections based on perturbative QCD.Comment: 34 pages, 3 figure

    Towards 1/N corrections to deep inelastic scattering from the gauge/gravity duality

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    1/N2 corrections to deep inelastic scattering (DIS) of charged leptons from glueballs at strong coupling are investigated in the framework of the gauge/gravity duality. The structure functions F1 and F2 (and also FL) are studied at subleading order in the 1/N2 expansion, in terms of q2 and the Bjorken parameter x. The relevant type IIB supergravity one-loop diagrams (which correspond to DIS with two-hadron final states) are studied in detail, while n-loop diagrams (corresponding to DIS with (n + 1)-hadron final states) are briefly discussed. The 1/N2n and Λ2/q2 dependence of the structure functions is analyzed. Within this context two very different limits are considered: one is the large N limit and the other one is when the virtual photon momentum transfer q is much larger than the infrared confining scale Λ. These limits do not commute.Facultad de Ciencias ExactasInstituto de Física La Plat

    Deep inelastic scattering off scalar mesons in the 1/N expansion from the D3D7-brane system

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    Deep inelastic scattering (DIS) of charged leptons off scalar mesons in the 1/N expansion is studied by using the gauge/gravity duality. We focus on the D3D7-brane system and investigate the corresponding structure functions by considering both the high energy limit and the 1/N expansion. These limits do not commute. From the D7-brane DBI action we derive a Lagrangian at sub-leading order in the D7-brane fluctuations and obtain a number of interactions some of which become relevant for two-hadron final-state DIS. By considering first the high energy limit followed by the large N one, our results fit lattice QCD data within 1.27% for the first three moments of F2 for the lightest pseudoscalar meson.Instituto de Física La Plat
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