2022-12-202022-12-202019-09-20Ablikim, M. vd. (2019). ''Complete measurement of the Λ electromagnetic form factors''. Physical Review Letters, 123(12).0031-90071079-7114https://doi.org/10.1103/PhysRevLett.123.122003https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.123.122003http://hdl.handle.net/11452/29992Çalışmada 482 yazar bulunmaktadır. Bu yazarlardan sadece Bursa Uludağ Üniversitesi mensuplarının girişleri yapılmıştır.The exclusive process e(+)e(-) -> Lambda(Lambda) over bar, with Lambda -> p pi(-) and (Lambda) over bar -> (p) over bar pi(+), has been studied at root s = 2.396 GeV for measurement of the timelike Lambda electric and magnetic form factors, G(E) and G(M). A data sample, corresponding to an integrated luminosity of 66.9 pb(-1), was collected with the BESIII detector for this purpose. A multidimensional analysis with a complete decomposition of the spin structure of the reaction enables a determination of the modulus of the ratio R = vertical bar G(E)/G(M)vertical bar and, for the first time for any baryon, the relative phase Delta Phi = Phi(E) - Phi(M). The resulting values are R = 0.96 +/- 0.14(stat) +/- 0.02(syst) and Phi(F) = 37 degrees +/- 12 degrees (stat) +/- 6 degrees (syst), respectively. These are obtained using the recently established and most precise value of the asymmetry parameter alpha(Lambda) = 0.750 +/- 0.010 measured by BESIII. In addition, the cross section is measured with unprecedented precision to be sigma = 118.7 +/- 5.3(stat) +/- 5.1(syst) pb, which corresponds to an effective form factor of vertical bar G vertical bar = 0.123 +/- 0.003(stat) +/- 0.003(syst). The contribution from two-photon exchange is found to be negligible. Our result enables the first complete determination of baryon timelike electromagnetic form factors.eninfo:eu-repo/semantics/openAccessObservablesGermanium compoundsHadronsAsymmetry parameterElectromagnetic form factorsIntegrated luminosityMagnetic form factorMulti-dimensional analysisRelative phaseSpin structuresTwo-photon exchangeApproximation theoryPhysicsArticle0004877435000042-s2.0-850727853321231231633986Physics, multidisciplinaryProton Scattering; Nucleons; HydrogenArticleBaryonDecompositionLuminancePhoton