Quarks are distributed differently in free protons and neutrons versus those inside nuclei, something called “the EMC effect.” Scientists previously thought that the EMC effect treated the up and down quarks in protons and neutrons equally. New high-precision data from the MARATHON experiment indicates that the EMC effect may exert more influence on the distribution of down quarks compared to up quarks inside nuclei.
Tag: Subatomic Particles
Precise Measurement of Pions Confirms Understanding of Fundamental Symmetry
Scientific rules about “chiral symmetry” predict the existence of subatomic particles called pions. The lifetime of a neutrally charged pion is tied to breaking of chiral symmetry. Until recently, measurements of this lifetime have been much less precise than calculations from theory. Physicists have now measured a pion’s lifetime more precisely than ever before.
Rutgers Expert Available to Discuss Supernova Discovery
New Brunswick, N.J. (April 21, 2021) – Rutgers University–New Brunswick astrophysicist John P. (Jack) Hughes is available for interviews on a supernova (exploding star) discovery published today in the journal Nature. The discovery, made with NASA’s Chandra X-ray Observatory, features…
Supercomputer Calculations May Give First Look at the Structure of Two-Faced Pions
Pions consist of a quark paired to an antiquark and are the lightest particles to experience the strong force. But until recently scientists did not understand pions’ internal structure because of their short lifespan. Now, an advance in supercomputer calculations using lattice Quantum Chromodynamics may allow scientists to provide an accurate and precise description of pion structure for the first time.
Searching for Signs of ‘Glueballs’ in Proton-Proton Smashups
In principle, the universe should contain objects composed only of gluons in a sea of quark-antiquark pairs. However, scientists’ experiments have never definitively confirmed these hypothetical objects, called “glueballs.” Now, scientists are using the Relativistic Heavy Ion Collider to search for signs of these glueballs.