A new Collection by the Physical Review journals celebrates the 50th anniversary of the discovery of asymptotic freedom in quantum chromodynamics (QCD)—the theoretical basis for the strong force of nature that binds quarks and gluons into hadrons.

The American Physical Society (APS) is pleased to announce that it will begin sponsoring Astrobites, a daily astrophysical literature journal written by graduate students in astronomy. This mutually beneficial collaboration aims to enhance the dissemination of research, educational resources, and career insights in the field of astronomy and astrophysics.

To mark the 243rd American Astronomical Society meeting, Physical Review Letters, Physical Review C, and Physical Review D highlighted several significant papers in astrophysics to illustrate the type of research these journals seek to publish.

With the goal of broadening its coverage of astrophysics, PRD hired astrophysicist Enrico Ramirez-Ruiz as an Associate Editor and appointed three experts in astrophysics to its Editorial Board.

Modeling of neutrino-nucleus scattering is essential to making sense of neutrino experimental data. In this paper, the MicroBooNE collaboration proposes and measures a set of generalized kinematic imbalance variables that are particularly well-suited for separating out and modeling nuclear effects. The usefulness of these variables is demonstrated by comparing data to event generators.

The authors study the effect of annihilating dark matter on massive stars suffering from pair-instability. The annihilation of dark matter inserts energy into the star and the authors show that for sufficient dark matter density, significant changes occur in the masses of the resulting black holes. For dark matter masses greater than 1 GeV, most of the dark matter is in the core which leads to a more violent explosion, resulting in a lighter black hole, while for masses less than .5 GeV, most of the dark matter is in the envelope, supporting the star through energy release, causing a less violent explosion and a more massive black hole.

The authors prove (under some mild assumptions) the conjecture about the rationality of the trace anomaly central charges $a$ and $c$ in $4D$ $N$= 2 superconformal theories. They work on the Higgs branch and use rigorous results from vertex operator algebras in their arguments. This closes some shortcomings of the Coulomb branch arguments and rigorously shows the generality of this intriguing property.

Scattering processes that produce multiple jets in the final states are abundant at the Large Hadron Collider, which makes the computation of the corresponding theoretical high-precision predictions a crucial task to perform. By using different methods, two different collaborations computed the five-parton scattering amplitudes at two-loops in Quantum Chromodynamics (QCD) for any number of colors, that is including all non-planar Feynman diagrams. In PhysRevD.109.094023 and PhysRevD.109.094024, the authors employed analytic reconstruction methods for amplitude computations, which expose drastically simpler structures in two-loop helicity amplitudes. The authors of the other collaboration in PhysRevD.109.094025 used tensor projection in the ’t Hooft-Veltman scheme and found analytic results for the scattering amplitudes expressed in terms of massless pentagon functions.

Giuseppe De Laurentis, Harald Ita, Maximillian Klinkert, and Vasily Sotnikov
Phys. Rev. D 109, 094023 (2024)

Giuseppe De Laurentis, Harald Ita, and Vasily Sotnikov
Phys. Rev. D 109, 094024 (2024)

This paper deals with interacting quantum field theories on a causal set. Free theories on these sets have been copiously discussed but here, the authors develop perturbative expansions, in-in and in-out correlators and make a suggestion on how to define an S-matrix, a daunting task, given the absence of Cauchy surfaces in a causal set.

The authors discuss $2D$ QCD with adjoint massless fermions and its deformation by the two (classically) marginal four-fermion operators, only one of which respects a noninvertible symmetry. They compute the $\beta$ functions of the two operators and discuss in detail their behavior in the IR, thereby clarifying some confusion in the literature stemming from different approaches, confinement behavior and treatment on the lattice. These are important results for this $laboratory$ of confinement and lattice formulations.

APS has selected 156 Outstanding Referees for 2024 who have demonstrated exceptional work in the assessment of manuscripts published in the Physical Review journals. A full list of the Outstanding Referees is available online.

From nature’s tiniest particles to waves that traverse the Universe—physicists remember resounding finds from the last half-century.

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