986 research outputs found
Weak-triplet, color-octet scalars and the CDF dijet excess
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.
Combining Social Cohesion Theories with Altered States of Consciousness to Explain the Adaptive Advantages of Spiritual Capacity in Humans
Light Weakly Coupled Axial Forces: Models, Constraints, and Projections
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
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
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)
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
- …