在重離子-重離子對撞中，藉由測量名為J/ψ 以及ψ(2S) 的夸克偶素的截面，可以提供我們豐富資訊來了解尚未明朗的夸克偶素的生成截面機制。STAR 是高能核物理實驗中位於相對論性重離子對撞機的主要實驗之一。我們藉由渺子探測器提供的觸發以及辨識渺子的功能去研究夸克偶素衰變到渺子-渺子對的過程，這個過程相比於衰變到電子-電子對，在探測器上具有比較小的軔致輻射能量損失，這項特性使我們能夠更精確的測量訊號。在這篇論文中，我們利用STAR 2017 年質子-質子510 GeV 對撞實驗的資料中測量了J/ψ 以及ψ(2S) 的微分截面以及ψ(2S) 衰變至J/ψ 的比例隨著橫向動量的變化。這是STAR 實驗中，第一次測量ψ(2S) 微分截面以及ψ(2S) 衰變到J/ψ 的比例隨著橫向動量的變化我們將測量結果與非相對論性量子色動力學(Non-Relativistic Quantum Chromodynamics) 以及改進的顏色蒸發模型(Improved Color Evaporation Model) 進行比較。

Measurements of the production cross sections of charmonia, namely J/ψ and ψ(2S), in hadron+hadron collisions provide valuable information about yet unsolved questions on the production cross section mechanisms of quarkonium. The Solenoid Tracker At RHIC (STAR) is one of the major highenergy nuclear physics experiment at the Relativistic Heavy Ion Collider. The Muon Telescope Detector, which provides trigger and identification capability for muons, enables to study quarkonia in the μ+ μ− decay channel which is less affected than the e+ e− channel by bremsstrahlung energy loss in the detector material, this feature allows us to measure the signal more accurately. In this thesis, we report on the measurements of production cross section, as well as their ratio as a function of pT in p+p collisions at √s = 510 GeV using data recorded in 2017 by the STAR experiment. It is the first differential measurement of the ψ(2S) differential cross section and ψ(2S) to the J/ψ yield ratio as a function of pT from STAR. The results are compared with the prediction from the Non-Relativistic Quantum Chromodynamics and Improved Color Evaporation Model.

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