CERN Collider Reveals Universe’s Bias Against Antimatter

• Scientists have observed that the laws of physics differ between particles that make up visible matter and their antiparticles.

• The Large Hadron Collider, the world’s largest particle accelerator, is used to observe this difference.

• The universe is primarily made of matter, not antimatter, but scientists believe that after the Big Bang, both must have existed in equal amounts.

• The discovery is based on CP violation, a difference in the behavior of matter and antimatter.

• The LHCb collaboration in Europe has reported the first-ever observation of CP violation in baryon decays, specifically in a particle called the b⁰ baryon.

• The discovery is a key step forward in understanding why the universe is made mostly of matter.

CP Violation in Baryon Degradations: A New Finding

• A new study focuses on the decay of the b⁰ baryon into a proton, a negatively charged kaon, a positively charged pion, and a negatively charged pion.

• The experiment used data from the Large Hadron Collider at CERN, specifically from the LHCb detector.

• The researchers used machine learning and particle identification tools to distinguish real decays from fake ones.

• The main quantity measured was the CP asymmetry, which compares the number of b⁰ decays to the number of b⁰-bar decays.

• The researchers used a control channel to correct for possible biases, such as proton-proton collisions producing more b⁰ than b⁰-bar.

• The researchers found a significant difference in the decay rates: about 2.45%.

• This is the first time CP violation has been observed in baryon decays, matching the predictions of the Standard Model, the main theory of particle physics.

• The study opens new ways to search for ‘new physics’, the name for hitherto unknown effects or particles beyond what the Model predicts.

• The study also requires the determination of the complex phase, a combination of variables present in the Cabibbo-Kobayashi-Maskawa (CKM) matrix, to determine the amount of violation.

• The study emphasizes the importance of observing CP violation in baryons as visible matter around us today is made of baryons.

The Sakharov Conditions and Matter’s Advantage in the Universe

• Andrei Sakharov, a Soviet physicist, proposed three conditions for the universe to be predominantly composed of only matter: Baryon number violation, CP violation in baryons, and departure from thermal equilibrium.

• The observed CP violation in baryon decays adds to CP violation among mesons.

• The complex phase of mesons’ violation has been measured, while that of baryons is pending.

• If the values match, it could indicate the Standard Model is correct, but leaves a gap between predicted matter-antimatter asymmetry and observed universe.

• If the values don’t match, it could signify ‘new physics’, requiring new theories and experiments.