English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Lattice QCD spectra can be used to constrain partial-wave scatteringamplitudes that, while satisfying unitarity, do not have to respect crossingsymmetry and analyticity. This becomes a particular problem when extrapolatedfar from real energies, e.g. in the case of broad resonances like the $\sigma$,leading to large systematic uncertainties in the pole position. In this letter,we will show how dispersion relations can implement the additional constraints,using as input lattice--determined $\pi\pi$ partial wave scattering amplitudeswith isospin--0,1,2. We will show that only certain combinations of amplitudeparameterizations satisfy all constraints, and that when we restrict to these,the $\sigma$ pole position is determined with minimal systematic uncertainty.The evolution of the now well-constrained $\sigma$ pole with varying lightquark mass is presented, showing how it transitions from a bound-state to abroad resonance.

Constraining the quark mass dependence of the lightest resonance in QCD