Browse Physics

A huge, predicted atomic parity violation has now been observed in ytterbium, further aiding tabletop experimental searches for physics beyond the standard model that complement ongoing efforts at high-energy colliders.

Measuring quantum interference of atomic matter waves may help detect experimental signatures of a fundamental theory of physics.

New connections have been made between experimental astrophysical signatures and theories that unify the electromagnetic, weak, and strong forces, called grand unified theories.

New results from the Fermi Gamma-Ray Space Telescope, the most precise to date in the energy range $20\text{GeV}$ to $1\text{TeV}$, should help resolve whether cosmic rays composed of the lightest charged particles, i.e., electrons and positrons, come from dark matter or some other astrophysical source.

Study of variations in the mass and interactions of quarks may reveal whether fundamental constants are governed by “environmental selection rules” that lead to complex universes capable of having observers.

Many cosmologists believe that antiprotons in cosmic rays come from the annihilation of dark matter. Data from the PAMELA experiment on board a Russian satellite provide an important test of this possibility.

The critical point is one of the main features of the phase diagram of strongly interacting quark-gluon matter. Finding this critical point in the lab will require luck and an understanding of the possible experimental signatures.

New upper limits on the spin-independent interaction of WIMPs and nucleons marks the latest volley in the worldwide effort to detect and identify particle dark matter.

Energetic particle jets created in relativistic heavy-ion collisions might create detectable shock waves as they travel through the quark-gluon plasma.

New arguments based on astrophysical phenomena constrain the possibility that dangerous black holes will be produced at the CERN Large Hadron Collider.

The BABAR collaboration at SLAC has observed the radiative decay of an excited state of bottomonium (the bound state of a bottom quark and its antiparticle) to its ground state η_{b}. Observing this long-sought ground state should enable better tests of quantum chromodynamic calculations of quark interactions and the computational approach called lattice quantum chromodynamics.

Forty years ago, it was predicted that there would be a sharp cutoff in the intensity of the very-high-energy cosmic rays that strike the earth’s surface. Two collaborations—the HiRes and Auger telescopes—are providing compelling evidence for this so-called “GZK effect.”