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Brendan Foster: on 6/12/12 at 19:39pm UTC, wrote FQXi will be starting a new habit of presenting "products" from Members...



FQXi FORUM
October 16, 2019

CATEGORY: Cosmology [back]
TOPIC: Equivalence Principle Violations [refresh]
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FQXi Administrator Brendan Foster wrote on Jun. 12, 2012 @ 19:39 GMT
FQXi will be starting a new habit of presenting "products" from Members supported by FQXi, here in the forums for open discussion.

To help start off this trend, please have a look at two articles from Member John Donoghue on Equivalence Principle violations using light [i.e. not heavy] fields. These articles were written as part of an FQXi-supported visit to the French physicist Thibault Damour.

Phenomenology of the Equivalence Principle with Light Scalars

Equivalence Principle Violations and Couplings of a Light Dilaton

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Lawrence B. Crowell wrote on Jun. 14, 2012 @ 18:17 GMT
I thought I would outline a bit about what a dilaton is, along with the other scalar field the axion. The graviton on the closed string has two directions of oscillation, x and y. These correspond to the creation and annihilation operators

a^μ_n, (a^μ_n)^† --- > x-direction

b^μ_n, (b^μ_n)^† --- > y-direction

and we can construct a general spin or m = 1 polarization state with (a^μ_n)^† + i(b^μ_n)^†, and a m = -1 state with (a^μ_n)^† - i(b^μ_n)^†. This polarization pertains to the string parameter space. This is not the graviton state, but the composition of two of these with mode matching n and –n, due to Noether’s theorem for equal left and right moving quanta, such as

((a^μ_n)^† + i(b^μ_n)^†)((a^ν_{-n})^† + i(b^ν_{-n})^†),

gives a spin 2 field corresponding to a curvature.

The graviton is massless. This means that a spin = 2 boson can’t be placed in a reference frame where the projection of that spin onto the momentum vector is zero. In other words the graviton can’t be put in a frame where where the particle is at rest. The same holds for the photon. However, with the graviton I can compose the two polarization states into a field

((a^μ_n)^† + i(b^μ_n)^†)((a^ν_{-n})^† - i(b^ν_{-n})^†),

which as a composition of m = 1 and m = -1 polarization states means this has a spin of zero. This particle state is a scalar state and is the dilaton field. The other field with spin = 0

((a^μ_n)^† - i(b^μ_n)^†)((a^ν_{-n})^† + i(b^ν_{-n})^†),

is the axion field. The axion field is involved with the CP symmetry of the strong interaction.

It is possible to construct a spin = 1 particle state. For the entire bulk in 10 dimensions there can be other dimensions beyond μ = 0, 1, 2, 3, there are others a = 5, 6, 7, 8, 9, 10. So we can have a graviton of the form

((a^μ_n)^† + i(b^μ_n)^†)((a^5_{-n})^† + i(b^5_{-n})^†).

If we curl up that fifth dimension in a Calabi-Yau space (say a circle if we consider only this additional dimension) the closed string becomes an open string with the raising and lower operators (a^μ_n)^† + i(b^μ_n)^† and a^μ_n + ib^μ_n, and this funny operator for this internal space, which in the case of only one additional fifth dimension is a photon or a gauge vector boson

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Steven Dinowitz wrote on Oct. 3, 2012 @ 18:24 GMT
I have yet to see any experimental data that rules out gross violation of the Equivalence Principle by systems composed wholly or in part of antiquarks - in other words Antibaryons (3 antiquarks) and mesons (a quark and an antiquark).

Using the simple but revolutionary assumption that antiquarks exhibit antigravity from my essay entitled: "The Law of Conservation of Baryon Number, Antimatter Antigravity, and the Experiment that Never Gets Done" I think I have discovered a simple relationship between the mass ratio of the quark and antiquark in any given meson and the gravitational acceleration that the meson experiences. It is predicted, for example, that a neutral kaon (consisting of a d-quark and anti-s-quark) with s/d quark mass ratio of about 21 will fall up at .91g in the Earth's gravitational field. Anyone interested please see my post of 9/19/12.

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