5,564 research outputs found
Bs Mixing and Electric Dipole Moments in MFV
We analyze the general structure of four-fermion operators capable of
introducing CP-violation preferentially in Bs mixing within the framework of
Minimal Flavor Violation. The effect requires a minimum of O(Yu^4 Yd^4) Yukawa
insertions, and at this order we find a total of six operators with different
Lorentz, color, and flavor contractions that lead to enhanced Bs mixing. We
then estimate the impact of these operators and of their close relatives on the
possible sizes of electric dipole moments (EDMs) of neutrons and heavy atoms.
We identify two broad classes of such operators: those that give EDMs in the
limit of vanishing CKM angles, and those that require quark mixing for the
existence of non-zero EDMs. The natural value for EDMs from the operators in
the first category is up to an order of magnitude above the experimental upper
bounds, while the second group predicts EDMs well below the current sensitivity
level. Finally, we discuss plausible UV-completions for each type of operator.Comment: 11 pages; v2: references adde
A Pointing Solution for the Medium Size Telescopes for the Cherenkov Telescope Array
An important aspect of the calibration of the Cherenkov Telescope Array is
the pointing, which enables an exact alignment of each telescope and therefore
allows to transform a position in the sky to a point in the plane of the
Cherenkov camera and vice versa. The favoured approach for the pointing
calibration of the medium size telescopes (MST) is the installation of an
optical CCD-camera in the dish of the telescope that captures the position of
the Cherenkov camera and of the stars in the night sky simultaneously during
data taking. The adaption of this approach is presented in this proceeding.Comment: 6 pages, 9 figures, Proceedings of the 6th International Symposium on
High-Energy Gamma-Ray Astronomy (Gamma2016
LHC Charge Asymmetry as Constraint on Models for the Tevatron Top Anomaly
The forward-backward asymmetry in top quark production at
the Tevatron has been observed to be anomalously large by both CDF and D0. It
has been suggested that a model with a coupling to and might
explain this anomaly, and other anomalies in mesons. Single-top-quark
production in this model is large, and arguably in conflict with Tevatron
measurements. However the model might still be viable if is
somewhat smaller than its current measured central value. We show that even
with smaller couplings, the model can be discovered (or strongly excluded) at
the LHC using the 2010 data sets. We find that a suitable charge-asymmetry
measurement is a powerful tool that can be used to constrain this and other
sources of anomalous single-top production, and perhaps other new high-energy
charge-asymmetric processes.Comment: 25 pages, 4 figures, note adde
Ground State of the Hydrogen Atom via Dirac Equation in a Minimal Length Scenario
In this work we calculate the correction to the ground state energy of the
hydrogen atom due to contributions arising from the presence of a minimal
length. The minimal length scenario is introduced by means of modifying the
Dirac equation through a deformed Heisenberg algebra (kempf algebra). With the
introduction of the Coulomb potential in the new Dirac energy operator, we
calculate the energy shift of the ground state of the hydrogen atom in first
order of the parameter related to the minimal length via perturbation theory.Comment: 11 page
Solutions of the Renormalisation Group Equation in Minimal Supersymmetric Standard Model
Renormalisation Group Equation(RGE) for color and top couplings sector of
MSSM has been solved. The mass of the top comes out to be 180.363 10.876
GeV and =. It is conjectured that the masses of the
other 11 fermions and the CKM phase angle can be theoretically
estimated. The results confirm the fact that the quarks and leptons have been
created having equal mass 115 GeV at the MSSM GUT scale GeV
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