The ATLAS and CMS collaborations used the full LHC Run 2 dataset to obtain new insights into the interaction
歐洲核子研究組織大型強子對撞機配備的實驗探測器，ATLAS(A Toroidal LHC Apparatus：環狀大型強子對撞機設備)及CMS(Compact Muon Solenoid：緊湊型μ介子螺線管)的共同研究，使用了大型強子對撞機第二次為期四年運作(LHC Run 2)的完整數據集，來獲得此交互作用的新洞察力。
圖1. ATLAS及CMS的核粒子生成，顯示希格斯玻色子與頂夸克一起被產生。 (圖援用自原文)
Recent years have seen the study of the Higgs boson progress from the discovery age to the measurement age. Among the latest studies of the properties of this unique particle by the ATLAS and CMS collaborations are measurements that shed further light on its interaction with top quarks – which, as the heaviest elementary particle, have the strongest interactions with the Higgs boson.
近年來已經看見希格斯玻色子的研究，從發現年代進展到測量年代。最近由ATLAS及CMS共同研究進行之此獨特粒子諸屬性的研究中，包括諸多進一步闡明，其與頂夸克交互作用的測定。身為最重基本粒子的頂夸克，具有與希格斯玻色子最強的交互作用。
In addition to allowing a determination of the strength of the top-Higgs interaction, the analyses open a new window on charge-parity (CP) violation.
除了使人得以確認，頂夸克與希格斯玻色子交互作用的強度之外，此些分析也開啟了，有關違反電荷奇偶性(CP)的新視窗。
Discovered unexpectedly more than 50 years ago, CP violation reveals a fundamental asymmetry in nature that causes rare differences in the rates of processes involving matter particles and their antimatter counterparts, and is therefore thought to be an essential ingredient to explaining the observed abundance of matter over antimatter in the universe.
五十多年前，違反電荷奇偶性意外被發現。這揭露了自然界中導致，在涉及物質粒子與其反物質對應物變化過程之速率中，出現罕見差異的一種基本不對稱。
While the Standard Model of particle physics can explain CP violation, the amount of CP violation observed so far in experiments – recently in the behaviour of charm quarks by the LHCb collaboration – is too small to account for the cosmological matter–antimatter imbalance. Searching for new sources of CP violation is thus of great interest to physicists.
儘管，粒子物理學的標準模型，能解釋違反電荷奇偶性。不過，迄今在實驗中，被觀測到的違反電荷奇偶性數量太少，無法說明宇宙論之物質與反物質的不平衡。因此，物理學家們非常感興趣於，搜尋違反電荷奇偶性的新來源。
In their recent studies, the CMS and ATLAS teams independently performed a direct test of the properties of the top–Higgs interaction. The studies are based on the full dataset of Run 2 of the LHC, which allowed for more precise measurements and analyses of the collision events where the Higgs boson is produced in association with one or two top quarks before decaying into two photons.
在最近的研究中，CMS及ATLAS的團隊獨立進行了，有關頂夸克與希格斯玻色子交互作用的屬性直接測試。此些研究是根據，大型強子對撞機第二次運作的完整數據集。這使人們得以更精確測定及分析，在衰變成兩個光子之前，希格斯玻色子被產生之與1或2個頂夸克關聯的對撞事件。
The detection of this extremely rare association, which was first observed by the two collaborations in 2018, required the full capacities of the detectors and analysis techniques.
這種於2018年，由上述兩共同研究，進行首度觀測之極其罕見的聯合偵測，需要完整的探測器及分析技術能耐。
As predicted by the Standard Model, no signs of CP violation were found in the top–Higgs interaction by either experiment. The top–Higgs production rate, a measure of the strength of the interaction between the particles, was also found by both experiments to be in line with previous results and consistent with the Standard Model predictions.
如同標準模型所預測，在由上述任一實驗之頂夸克與希格斯玻色子的交互作用中，皆未發現違反電荷奇偶性的跡象。不過，這兩實驗發現頂夸克與希格斯玻色子的產生率(這兩種粒子之間交互作用強度的一種測定)，與先前的研究結果相符合，且與標準模型的預測一致。
Following these first investigations of CP violation in the top–Higgs interaction, ATLAS and CMS physicists plan to study other Higgs-boson decay channels as part of the decades-long search for the origin of the universe’s missing antimatter.
繼證些在頂夸克與希格斯玻色子交互作用中，違反電荷奇偶性的首度調查研究之後，ATLAS及CMS的物理學家們，計劃研究其他希格斯玻色子的衰變途徑，作為數十年來尋找，宇宙行蹤不明之反物質起因的一部分。
原文網址：https://home.cern/news/news/physics/searching-matter-antimatter-asymmetry-higgs-boson-top-quark-interaction
翻譯：許東榮
文章定位：
