986 research outputs found

    Weak-triplet, color-octet scalars and the CDF dijet excess

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    We extend the standard model to include a weak-triplet and color-octet scalar. This `octo-triplet' field consists of three particles, two charged and one neutral, whose masses and renormalizable interactions depend only on two new parameters. The charged octo-triplet decay into a W boson and a gluon is suppressed by a loop factor and an accidental cancellation. Thus, the main decays of the charged octo-triplet may occur through higher-dimensional operators, mediated by a heavy vectorlike fermion, into quark pairs. For an octo-triplet mass below the t\bar{b} threshold, the decay into Wb\bar{b} or Wb\bar{s} through an off-shell top quark has a width comparable to that into c\bar{s} or c\bar{b}. Pair production with one octo-triplet decaying into two jets and the other decaying into a W and two soft b jets may explain the dijet-plus-W excess reported by the CDF Collaboration. Using a few kinematic distributions, we compare two mechanisms of octo-triplet pair production: through an s-channel coloron and through the coupling to gluons. The higher-dimensional operators that allow dijet decays also lead to CP violation in B_s - \bar B_s mixing.Comment: 18 pages. New CDF kinematic distributions using 7.3 fb^{-1} compared to both resonant and gluon-induced pair production of octets. Corrections in Section 3.1. Comment on the D0 Wjj result included in Section 3.3. Implications for LHC expanded in Section 3.

    Revising the Conjunctive Approach in the American Southwest

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    Light Weakly Coupled Axial Forces: Models, Constraints, and Projections

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    We investigate the landscape of constraints on MeV-GeV scale, hidden U(1) forces with nonzero axial-vector couplings to Standard Model fermions. While the purely vector-coupled dark photon, which may arise from kinetic mixing, is a well-motivated scenario, several MeV-scale anomalies motivate a theory with axial couplings which can be UV-completed consistent with Standard Model gauge invariance. Moreover, existing constraints on dark photons depend on products of various combinations of axial and vector couplings, making it difficult to isolate the effects of axial couplings for particular flavors of SM fermions. We present a representative renormalizable, UV-complete model of a dark photon with adjustable axial and vector couplings, discuss its general features, and show how some UV constraints may be relaxed in a model with nonrenormalizable Yukawa couplings at the expense of fine-tuning. We survey the existing parameter space and the projected reach of planned experiments, briefly commenting on the relevance of the allowed parameter space to low-energy anomalies in pi^0 and 8-Be* decay.Comment: 30 pages, 5 figures, 4 tables. v2: format changed to JHEP, typos fixed, references adde

    HIF and c-Myc: Sibling Rivals for Control of Cancer Cell Metabolism and Proliferation

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    O2 deprivation (hypoxia) and cellular proliferation engage opposite cellular pathways, yet often coexist during tumor growth. The ability of cells to grow during hypoxia results in part from crosstalk between hypoxia-inducible factors (HIFs) and the proto-oncogene c-Myc. Acting alone, HIF and c-Myc partially regulate complex adaptations undertaken by tumor cells growing in low O2. However, acting in concert these transcription factors reprogram metabolism, protein synthesis, and cell cycle progression, to “fine tune” adaptive responses to hypoxic environments

    Symmetric Jacobians

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    This article is about polynomial maps with a certain symmetry and/or antisymmetry in their Jacobians, and whether the Jacobian Conjecture is satisfied for such maps, or whether it is sufficient to prove the Jacobian Conjecture for such maps. For instance, we show that it suffices to prove the Jacobian conjecture for polynomial maps x + H over C such that JH satisfies all symmetries of the square, where H is homogeneous of arbitrary degree d >= 3.Comment: 18 pages, minor corrections, grayscale eepic boxes have been replaced by colorful tikz boxe

    On the theory of Gordan-Noether on homogeneous forms with zero Hessian (Improved version)

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    We give a detailed proof for Gordan-Noether's results in "Ueber die algebraischen Formen, deren Hesse'sche Determinante identisch verschwindet" published in 1876 in Mathematische Annahlen. C. Lossen has written a paper in a similar direction as the present paper, but did not provide a proof for every result. In our paper, every result is proved. Furthermore, our paper is independent of Lossen's paper and includes a considerable number of new observations. An earlier version of this paper has been printed in Proceedings of the School of Science of Tokai University, Vol.49, Mar. 2014. In this version, a serious error has been corrected and some new results have been added
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