Completando las teorías de Einstein: un gran avance en la física de partículas

Investigadores de la Universidad de Osaka muestran la contracción relativista de un campo eléctrico producido por partículas cargadas que se mueven rápidamente, como predice la teoría de Einstein, lo que puede ayudar a mejorar la investigación sobre radiación y la física de partículas.

Hace más de un siglo, uno de los físicos modernos más famosos, Albert Einstein, propuso la innovadora teoría de la relatividad especial. La mayor parte de todo lo que sabemos sobre el universo se basa en esta teoría, sin embargo, parte de ella no se ha probado experimentalmente hasta ahora. científicos de de la Universidad de Osaka El Instituto de Ingeniería Láser ha utilizado por primera vez mediciones electro-ópticas ultrarrápidas para visualizar la contracción del campo eléctrico que rodea un haz de electrones que viajan cerca de la velocidad de la luz y demostrar el proceso de generación.

De acuerdo con la teoría especial de la relatividad de Einstein, es necesario utilizar una «transformación de Lorentz» que combina las coordenadas del espacio y el tiempo para describir con precisión el movimiento de los objetos que pasan por un observador a velocidades cercanas a la velocidad de la luz. Pudo explicar cómo estas transformaciones llevaron a ecuaciones autoconsistentes para campos eléctricos y magnéticos.

Si bien varios efectos de la relatividad se han demostrado numerosas veces con un alto grado de experimentación[{» attribute=»»>accuracy, there are still parts of relativity that have yet to be revealed in experiments. Ironically, one of these is the contraction of the electric field, which is represented as a special relativity phenomenon in electromagnetism.

Illustration of the formation process of the planar electric field contraction that accompanies the propagation of a near-light-speed electron beam (shown as an ellipse in the figure). Credit: Masato Ota, Makoto Nakajima

Now, the research team at Osaka University has demonstrated this effect experimentally for the first time. They accomplished this feat by measuring the profile of the Coulomb field in space and time around a high-energy electron beam generated by a linear particle accelerator. Using ultrafast electro-optic sampling, they were able to record the electric field with extremely high temporal resolution.

It has been reported that the Lorentz transformations of time and space as well as those of energy and momentum were demonstrated by time dilation experiments and rest mass energy experiments, respectively. Here, the team looked at a similar relativistic effect called electric-field contraction, which corresponds to the Lorentz transformation of electromagnetic potentials.

“We visualized the contraction of an electric field around an electron beam propagating close to the speed of light,” says Professor Makoto Nakajima, the project leader. In addition, the team observed the process of electric-field contraction right after the electron beam passed through a metal boundary.

When developing the theory of relativity, it is said that Einstein used thought experiments to imagine what it would be like to ride on a wave of light. “There is something poetic about demonstrating the relativistic effect of electric fields more than 100 years after Einstein predicted it,” says Professor Nakajima. “Electric fields were a crucial element in the formation of the theory of relativity in the first place.”

This research, with observations matching closely to Einstein’s predictions of special relativity in electromagnetism, can serve as a platform for measurements of energetic particle beams and other experiments in high-energy physics.

Reference: “Ultrafast visualization of an electric field under the Lorentz transformation” by Masato Ota, Koichi Kan, Soichiro Komada, Youwei Wang, Verdad C. Agulto, Valynn Katrine Mag-usara, Yasunobu Arikawa, Makoto R. Asakawa, Youichi Sakawa, Tatsunosuke Matsui and Makoto Nakajima, 20 October 2022, Nature Physics.
DOI: 10.1038/s41567-022-01767-w

The study was funded by the Japan Society for the Promotion of Science and the NIFS Collaborative Research Program.