Abstract
We report the first observation of the spontaneous polarization of Λ and Λ[over ¯] hyperons transverse to the production plane in e^{+}e^{-} annihilation, which is attributed to the effect arising from a polarizing fragmentation function. For inclusive Λ/Λ[over ¯] production, we also report results with subtracted feed-down contributions from Σ^{0} and charm. This measurement uses a dataset of 800.4 fb^{-1} collected by the Belle experiment at or near a center-of-mass energy of 10.58GeV. We observe a significant polarization that rises with the fractional energy carried by the Λ/Λ[over ¯] hyperon.
Highlights
We report the first observation of the spontaneous polarization of Λ and Λhyperons transverse to the production plane in eþe− annihilation, which is attributed to the effect arising from a polarizing fragmentation function
This tension helped put in motion a program to study transverse-spin phenomena [3], which has been a major focus of the hadron physics community ever since
We present here the first observation of the transverse polarization of Λ hyperons produced in eþe− annihilation, from which D⊥1TΛ=q can be extracted
Summary
We report the first observation of the spontaneous polarization of Λ and Λhyperons transverse to the production plane in eþe− annihilation, which is attributed to the effect arising from a polarizing fragmentation function. The fragmentation function (FF), describing the production of transversely polarized Λ hyperons [5] from unpolarized quarks, is denoted by D⊥1TΛ=qðz; p2⊥Þ [6,7]. This measurement considers the processes eþe− → ΛðΛ ÞX as well as associated production eþe− → ΛðΛ ÞhÆX, where h denotes a light hadron (h 1⁄4 π, K) on the opposite side and provides additional information on the fragmenting quark flavor [9].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
