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

We have performed the most comprehensive resonance-model fit of$\pi^-\pi^-\pi^+$ states using the results of our previously publishedpartial-wave analysis (PWA) of a large data set of diffractive-dissociationevents from the reaction $\pi^- + p \to \pi^-\pi^-\pi^+ + p_\text{recoil}$ witha 190 GeV/$c$ pion beam. The PWA results, which were obtained in 100 bins ofthree-pion mass, $0.5 < m_{3\pi} < 2.5$ GeV/$c^2$, and simultaneously in 11bins of the reduced four-momentum transfer squared, $0.1 < t' < 1.0$$($GeV$/c)^2$, are subjected to a resonance-model fit using Breit-Wigneramplitudes to simultaneously describe a subset of 14 selected waves using 11isovector light-meson states with $J^{PC} = 0^{-+}$, $1^{++}$, $2^{++}$,$2^{-+}$, $4^{++}$, and spin-exotic $1^{-+}$ quantum numbers. The modelcontains the well-known resonances $\pi(1800)$, $a_1(1260)$, $a_2(1320)$,$\pi_2(1670)$, $\pi_2(1880)$, and $a_4(2040)$. In addition, it includes thedisputed $\pi_1(1600)$, the excited states $a_1(1640)$, $a_2(1700)$, and$\pi_2(2005)$, as well as the resonancelike $a_1(1420)$. We measure theresonance parameters mass and width of these objects by combining theinformation from the PWA results obtained in the 11 $t'$ bins. We extract therelative branching fractions of the $\rho(770) \pi$ and $f_2(1270) \pi$ decaysof $a_2(1320)$ and $a_4(2040)$, where the former one is measured for the firsttime. In a novel approach, we extract the $t'$ dependence of the intensity ofthe resonances and of their phases. The $t'$ dependence of the intensities ofmost resonances differs distinctly from the $t'$ dependence of the nonresonantcomponents. For the first time, we determine the $t'$ dependence of the phasesof the production amplitudes and confirm that the production mechanism of thePomeron exchange is common to all resonances.

Light isovector resonances in $\pi^- p \to \pi^-\pi^-\pi^+ p$ at 190 GeV/${\it c}$