Continuum spectra from warped dimensions Megías, Eugenio; Quirós, Mariano
Nuclear and particle physics proceedings,
November 2022, 2022-11-00, Volume:
318-323
Journal Article
Peer reviewed
Open access
Using a five dimensional (5D) warped model with two branes along the extra dimension, we study the Green's functions for gauge bosons with a mass gap mg=ρ/2 and a continuum for s>mg2. We find that ...the Green's functions exhibit poles in the second Riemann sheet of the complex s plane, denoting the existence of broad resonances. The positivity of the spectral functions is also analyzed. Finally, it is shown how the Green's functions can modify some Standard Model processes in pp collisions.
One of the most important and unanswered problems in particle physics is the origin of the three generations of quarks and leptons. The Standard Model does not provide any hint regarding its ...sequential charge assignments, which remain a fundamental mystery of Nature. One possible solution of the puzzle is to look for charge assignments, in a given gauge theory, that are inter-generational, by employing the cancellation of the gravitational and gauge anomalies horizontally. The 331 model, based on an SU(3)C×SU(3)L×U(1)X does this in an economical way and defines a possible extension of the Standard Model, where the number of families has necessarily to be three. We review the model in Pisano, Pleitez, and Frampton's formulation, which predicts the existence of bileptons. Another characteristics of the model is to unify the SU(3)C×SU(2)L×U(1)X into the 331 symmetry at a scale that is in the TeV range. Expressions of the scalar mass eigenstates and of the renormalization group equations of the model are also presented.
Weak Polarized Electron Scattering Erler, Jens; Horowitz, Charles J; Mantry, Sonny ...
Annual review of nuclear and particle science,
10/2014, Volume:
64, Issue:
1
Journal Article
Peer reviewed
Open access
Scattering polarized electrons provides an important probe of the weak interactions. Precisely measuring the parity-violating left-right cross-section asymmetry (
A
LR
) is the goal of a number of ...experiments that have recently been completed or are in progress. The experiments are challenging, given that
A
LR
is small, typically between 10
−4
and 10
−8
. By carefully choosing appropriate targets and kinematics, one can isolate various pieces of the weak Lagrangian, providing a search for physics beyond the Standard Model. For other choices, unique features of the strong interaction are being studied, including the radius of the neutron density in heavy nuclei, charge symmetry violation, and higher-twist terms. This article reviews the theory behind the experiments, as well as the general techniques used in the experimental program.
Abstract
We have trapped BaF molecules in neon ice and used laser-induced fluorescence spectroscopy to map out their optical transitions. Our measurements show that the neon lattice does not ...significantly perturb certain optical transitions in trapped BaF molecules. We used one such transition to optically pump and detect spin resonances in the molecules. This demonstration of optical control of trapped heavy polar molecules offers opportunities to advance physical chemistry and ultra-high-energy physics.
We present updated global fits of the Standard Model and beyond to electroweak precision data, taking into account recent progress in theoretical calculations and experimental measurements. From the ...fits, we derive model-independent constraints on new physics by introducing oblique and epsilon parameters, and modified Zbb‾ and HVV couplings. Furthermore, we also perform fits of the scale factors of the Higgs-boson couplings to observed signal strengths of the Higgs boson.
In this contribution, we discuss the cosmological scenario where unstable domain walls are formed in the early universe and their late-time annihilation produces a significant amount of gravitational ...waves. After describing cosmological constraints on long-lived domain walls, we estimate the typical amplitude and frequency of gravitational waves observed today. We also review possible extensions of the standard model of particle physics that predict the formation of unstable domain walls and can be probed by observation of relic gravitational waves. It is shown that recent results of pulser timing arrays and direct detection experiments partially exclude the relevant parameter space, and that a much wider parameter space can be covered by the next generation of gravitational wave observatories.
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