Access Type

Open Access Dissertation

Date of Award

January 2017

Degree Type


Degree Name



Physics and Astronomy

First Advisor

Gil Paz


This dissertation describes two topics in high-energy physics. In the first we describe the

extraction of the magnetic radius of the proton. In the second we impose LHC constraints on

the combined anomaly and Z’ mediation mechanisms of supersymmetry breaking.

We combine constraints from analyticity with experimental electron-proton scattering data

to determine the proton magnetic radius without model-dependent assumptions on the shape

of the form factor. We also study the impact of including electron-neutron scattering data,

and ππ ! NN¯ data. Using representative datasets we find for a cut of Q2 ≤ 0:5 GeV2,



= 0:91+0:03

−0:06 ± 0:02 fm using just proton scattering data; rMp = 0:87+0 −0: :04 05 ± 0:01 fm adding

neutron data; and rMp = 0:87+0 −0: :02 02 fm adding ππ data. We also extract the neutron magnetic

radius from these data sets obtaining rMn = 0:89+0 −0: :03 03 fm from the combined proton, neutron,

and ππ data. Particle Data Group (PDG) has reported both of these values, rMp = 0:87 ± 0:02

fm and rn

M = 0:89 ± 0:03 fm in their 2016 listing of the magnetic radius of the proton and

neutron, respectively.

Combining anomaly with Z0 mediation allows us to solve the tachyonic problem of the

former and avoid fine tuning in the latter. This model includes an extra U(1)0 gauge symmetry

and extra singlet scalar S which provides a solution to the ‘µ problem’ of the MSSM. The

low-energy particle spectrum is calculated from the UV inputs using the Renormalization

Group Equations. The benchmark points considered in the original model, suggested before

the Higgs discovery, predicted a Higgs mass close to the current measured value of 125 GeV.

We use the current LHC data to update the predictions of the model, its particle spectrum

and in particular the mass of the Z0 gauge boson.

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