A hadron resonance gas model including all known particles and resonances with masses m < 2 GeV and an exponentially rising density of Hagedorn states for m > 2 GeV is used to obtain an upper bound on the shear viscosity to entropy density ratio, eta/s approximately 1/(4pi), of hadronic matter near Tc. We found a large trace anomaly and small speed of sound near Tc, which agree well with recent lattice calculations. We comment on the bulk viscosity to entropy density ratio close to Tc.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.103.172302 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Search for violation in decays in proton-proton collisions at .
Eur Phys J C Part Fields
December 2024
Article Synopsis
- The CMS experiment conducted a search for charge-parity violation in decays using proton-proton collision data from 2018, analyzing around 10 billion events with b hadrons decaying into charm hadrons.
- The flavor of the neutral D meson was determined through the charge of pions in the reconstructed decays, and an asymmetry measurement in the decays was reported, taking into account various uncertainties.
- This research marks the first asymmetry measurement by the CMS in the charm sector and the first to use a fully hadronic final state in such analyses.
ω Meson from Lattice QCD.
Phys Rev Lett
November 2024
Helmholtz-Institut für Strahlen- und Kernphysik (Theorie) and Bethe Center for Theoretical Physics, Universität Bonn, 53115 Bonn, Germany.
Many excited states in the hadron spectrum have large branching ratios to three-hadron final states. Understanding such particles from first principles QCD requires input from lattice QCD with one-, two-, and three-meson interpolators as well as a reliable three-body formalism relating finite-volume spectra at unphysical pion mass values to the scattering amplitudes at the physical point. In this work, we provide the first-ever calculation of the resonance parameters of the ω meson from lattice QCD, including an update of the formalism through matching to effective field theories.
View Article and Find Full Text PDFArticle Synopsis
- The study focuses on detecting multijet signatures from proton-proton collisions at a high energy of 13 TeV, analyzing a dataset totaling 128 fb^{-1}.
- A special data scouting method is utilized to pick out events with low combined momentum in jets.
- This research is pioneering in its investigation of electroweak particle production in R-parity violating supersymmetric models, particularly examining hadronically decaying mass-degenerate higgsinos, and it broadens the limits on the existence of R-parity violating top squarks and gluinos.
The first search for soft unclustered energy patterns (SUEPs) is performed using an integrated luminosity of 138 fb^{-1} of proton-proton collision data at sqrt[s]=13 TeV, collected in 2016-2018 by the CMS detector at the LHC. Such SUEPs are predicted by hidden valley models with a new, confining force with a large 't Hooft coupling. In events with boosted topologies, selected by high-threshold hadronic triggers, the multiplicity and sphericity of clustered tracks are used to reject the background from standard model quantum chromodynamics.
View Article and Find Full Text PDFQCD evolution of entanglement entropy.
Rep Prog Phys
December 2024
Department of Physics, Brookhaven National Laboratory, Upton, NY 11973, United States of America.
Article Synopsis
- Entanglement entropy is being used to explore complex quantum chromodynamics (QCD) phenomena, particularly around how protons confine color.
- This study focuses on the rapidity-dependent entanglement entropy in protons and its relationship to hadron production, an area not previously explored in detail.
- The results show a strong match between theoretical entropy calculations from QCD and experimental hadron entropy data, suggesting the existence of a maximally entangled state and enhancing our understanding of protons' nonperturbative structure.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!