LHC tagged posts

The discovery of the Higgs boson in 2012 slotted in the final missing piece of the Standard Model puzzle. Yet, it left lingering questions. What lies beyond this framework? Where are the new phenomena that would solve the universe’s remaining mysteries, such as the nature of dark matter and the origin of matter-antimatter asymmetry?

One parameter that may hold clues about new physics phenomena is the “width” of the W boson, the electrically charged carrier of the weak force. A particle’s width is directly related to its lifetime and describes how it decays to other particles. If the W boson decays in unexpected ways, such as into yet-to-be-discovered new particles, these will influence the measured width.

As the Standard Model precisely predicts its value based on the strength o...

New findings lay the foundation for the search for dark matter. How are galaxies born, and what holds them together? Astronomers assume that dark matter plays an essential role. However, as yet it has not been possible to prove directly that dark matter exists. A research team including Technical University of Munich (TUM) scientists has now measured for the first time the survival rate of antihelium nuclei from the depths of the galaxy – a necessary prerequisite for the indirect search for Dark Matter.

Many things point to the existence of dark matter...

The figure shows how a small, elongated drop of quark-gluon plasma is formed when two atomic nuclei hit each other a bit off center. The angular distribution of the emitted particles makes it possible to determine the properties of the quark-gluon plasma, including the viscosity. Credit: State University of New York

Researchers collided lead atoms with extremely high energy in the 27 km long particle accelerator. The primordial soup is a quark-gluon plasma and researchers have measured its liquid properties with great accuracy at the LHC’s top energy. A few billionths of a second after the Big Bang, the universe was made up extremely hot and dense primordial soup of quarks and gluons. By colliding lead nuclei at a record-high 5...

In this event display from the LHCb experiment at CERN’s Large Hadron Collider, proton-proton collisions at the interaction point (far left) result in a shower of leptons and other charged particles. The yellow and green lines are computer-generated reconstructions of the particles’ trajectories through the layers of the LHCb detector. Credit: CERN/LHCb Collaboration

A team of CERN physicists has found leptons being treated in strange ways not predicted by the Standard Model. The discovery could prove to be a significant lead in the search for non-standard phenomena.