1,770 research outputs found

    Alignment of the ATLAS inner detector for the LHC Run II

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    ATLAS a multipurpose experiment at the LHC proton-proton collider. Its physics goals require high resolution, unbiased measurement of all charged particle kinematic parameters. These critically depend on the layout and performance of the tracking system, notably quality of its offline alignment. ATLAS is equipped with a tracking system built using different technologies, silicon planar sensors (pixel and micro-strip) and gaseous drift- tubes, all embedded in a 2T solenoidal magnetic field. For the LHC Run II, the system has been upgraded with the installation of a new pixel layer, the Insertable B-layer (IBL). Offline track alignment of the ATLAS tracking system has to deal with about 700,000 degrees of freedom (DoF) defining its geometrical parameters. The task requires using very large data sets and represents a considerable numerical challenge in terms of both CPU time and precision. The adopted strategy uses a hierarchical approach to alignment, combining local and global least squares techniques. An outline of the track based alignment approach and its implementation within the ATLAS software will be presented. Special attention will be paid to integration to the alignment framework of the IBL, which plays the key role in precise reconstruction of the collider luminous region, interaction vertices and identification of long-lived heavy flavor states. Techniques allowing to pinpoint and eliminate tracking systematics due to alignment as well as strategies to deal with time-dependent variations will be briefly covered. The first results from Cosmic Ray commissioning runs and status from proton-proton collision in LHC Run II will be discussed

    Baryonic Generating Functions

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    We show how it is possible to use the plethystic program in order to compute baryonic generating functions that count BPS operators in the chiral ring of quiver gauge theories living on the world volume of D branes probing a non compact CY manifold. Special attention is given to the conifold theory and the orbifold C^2/Z_2 times C, where exact expressions for generating functions are given in detail. This paper solves a long standing problem for the combinatorics of quiver gauge theories with baryonic moduli spaces. It opens the way to a statistical analysis of quiver theories on baryonic branches. Surprisingly, the baryonic charge turns out to be the quantized Kahler modulus of the geometry.Comment: 44 pages, 7 figures; fonts change

    Integrability on the Master Space

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    It has been recently shown that every SCFT living on D3 branes at a toric Calabi-Yau singularity surprisingly also describes a complete integrable system. In this paper we use the Master Space as a bridge between the integrable system and the underlying field theory and we reinterpret the Poisson manifold of the integrable system in term of the geometry of the field theory moduli space.Comment: 47 pages, 20 figures, using jheppub.st

    Beta, Dipole and Noncommutative Deformations of M-theory Backgrounds with One or More Parameters

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    We construct new M-theory solutions starting from those that contain 5 U(1) isometries. We do this by reducing along one of the 5-torus directions, then T-dualizing via the action of an O(4,4) matrix and lifting back to 11-dimensions. The particular T-duality transformation is a sequence of O(2,2) transformations embedded in O(4,4), where the action of each O(2,2) gives a Lunin-Maldacena deformation in 10-dimensions. We find general formulas for the metric and 4-form field of single and multiparameter deformed solutions, when the 4-form of the initial 11-dimensional background has at most one leg along the 5-torus. All the deformation terms in the new solutions are given in terms of subdeterminants of a 5x5 matrix, which represents the metric on the 5-torus. We apply these results to several M-theory backgrounds of the type AdS_r x X^{11-r}. By appropriate choices of the T-duality and reduction directions we obtain analogues of beta, dipole and noncommutative deformations. We also provide formulas for backgrounds with only 3 or 4 U(1) isometries and study a case, for which our assumption for the 4-form field is violated.Comment: v2:minor corrections, v3:small improvements, v4:conclusions expanded, to appear in Class. Quant. Gra

    On the Moduli Space of the Cascading SU(M+p)xSU(p) Gauge Theory

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    We carry out a thorough analysis of the moduli space of the cascading gauge theory found on p D3-branes and M wrapped D5-branes at the tip of the conifold. We find various mesonic branches of the moduli space whose string duals involve the warped deformed conifold with different numbers of mobile D3-branes. The branes that are not mobile form a BPS bound state at threshold. In the special case where p is divisible by M there also exists a one-dimensional baryonic branch whose family of supergravity duals, the resolved warped deformed conifolds, was constructed recently. The warped deformed conifold is a special case of these backgrounds where the resolution parameter vanishes and a Z_2 symmetry is restored. We study various brane probes on the resolved warped deformed conifolds, and successfully match the results with the gauge theory. In particular, we show that the radial potential for a D3-brane on this space varies slowly, suggesting a new model of D-brane inflation.Comment: 55 pages, 8 figures; v2: minor corrections; v3: added comments in section 1

    Brane Tilings and Exceptional Collections

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    Both brane tilings and exceptional collections are useful tools for describing the low energy gauge theory on a stack of D3-branes probing a Calabi-Yau singularity. We provide a dictionary that translates between these two heretofore unconnected languages. Given a brane tiling, we compute an exceptional collection of line bundles associated to the base of the non-compact Calabi-Yau threefold. Given an exceptional collection, we derive the periodic quiver of the gauge theory which is the graph theoretic dual of the brane tiling. Our results give new insight to the construction of quiver theories and their relation to geometry.Comment: 46 pages, 37 figures, JHEP3; v2: reference added, figure 13 correcte

    Comparative analysis of the biosimilar and innovative G-CSF modulated pathways on umbilical cord blood–derived mononuclear cells

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    Biosimilars of granulocyte colony-stimulating factor (G-CSF) have been routinely introduced into clinical practice. However, not functional genomics characterization has been performed yet in comparison with the innovator G-CSF. This study aimed to evaluate the transcriptomic changes in an in vitro model of umbilical cord blood cells (UBC) exposed to G-CSF for the identification of their modulated pathways. Umbilical cord blood cells–derived mononuclear cells (MNCs) were treated with biosimilar and innovator G-CSF for further gene expression profiling analysis using a microarray-based platform. Comparative analysis of biosimilar and innovator G-CSF gene expression signatures allowed us to identify the most commonly modulated pathways by both drugs. In brief, we observed predominantly upmodulation of transcripts related to PI3K-Akt, NF-kappaB, and tumor necrosis factor (TNF) signaling pathways as well as transcripts related to negative regulation of apoptotic process among others. In addition, hematopoietic colony-forming cell assays corroborate the G-CSF phenotypic effects over UBC-derived MNCs. In conclusion, our study suggests that G-CSF impacts UBC-derived cells through the modulation of several signaling pathways associated with cell survival, migration, and proliferation. The concordance observed between biosimilar and innovator G-CSF emphasizes their similarity in regards to their specificity and biological responses.Fil: Ávila Portillo, Luz Mabel. Universidad Nacional de Colombia; Colombia. Stem Medicina Regenerativa/CryoHoldco; Colombia. Hospital Militar Central. Unidad de Investigación; ColombiaFil: Aristizabal, F.. Universidad Nacional de Colombia; ColombiaFil: Perdomo, S.. Universidad El Bosque. Facultad de Odontología; ColombiaFil: Riveros, A.. Stem Medicina Regenerativa/CryoHoldco; ColombiaFil: Ospino, B.. Stem Medicina Regenerativa/CryoHoldco; ColombiaFil: Avila, J. P.. Stem Medicina Regenerativa/CryoHoldco; ColombiaFil: Butti, M.. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Inmunológicas Básicas y Aplicadas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Abba, Martín Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Inmunológicas Básicas y Aplicadas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentin

    Operator Counting and Eigenvalue Distributions for 3D Supersymmetric Gauge Theories

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    We give further support for our conjecture relating eigenvalue distributions of the Kapustin-Willett-Yaakov matrix model in the large N limit to numbers of operators in the chiral ring of the corresponding supersymmetric three-dimensional gauge theory. We show that the relation holds for non-critical R-charges and for examples with {\mathcal N}=2 instead of {\mathcal N}=3 supersymmetry where the bifundamental matter fields are nonchiral. We prove that, for non-critical R-charges, the conjecture is equivalent to a relation between the free energy of the gauge theory on a three sphere and the volume of a Sasaki manifold that is part of the moduli space of the gauge theory. We also investigate the consequences of our conjecture for chiral theories where the matrix model is not well understood.Comment: 27 pages + appendices, 5 figure
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