我利用SU(3)的方法，系統性的分析強子衰變的柘樸振幅(topological amplitude)。它可以一面保持SU(3) 對稱性，一面提供對不同柘樸振幅大小的估算。這個方法可以輕易的得出大家熟悉的結果，並可運用到更為複雜的情况，如包含重子及五重夸克(pentaquark)重子的系統。我和我的合作者也用之來預測B介子的二體強子衰變率及五重夸克重子的衰變率。
我利用光前夸克模型計算了自旋1/2及3/2的重強子的弱衰變形狀因子(form factor)，並用它來預測一些重強子的衰變率。這是一個相當複雜的計算。我幾乎從頭推導及發展出許多重要的計算方法和結果，其中包含了糾正前人的計算結果。令人振奮的是，我所得出的形狀因子合理的符合重夸克對稱性(heavy quark symmetry)的要求及期望。
在暗物質的硏究方面，我和我的合作者系統性的探討了狄拉克費米子暗物質的性質。我們的結論是，根據目前的實驗數據，這些費米子暗物質的質量都相當的高，而在這些探討中索末斐增強效用(Sommerfeld enhancement effect)扮演了重要的角色。
李政道：“假如你有一個方向是對的話，它這東西自己就有些邏輯出來。好像你發掘古蹟一様 … 假如說你做的東西不勉强，你就知道這個東西好，如果你每做一步就要加一個假設的話，這個東西就不一定靠得住。”(物理雙月刊，十四卷五期，中華民國物理學會,1992年，第516頁)
海森堡：“我想你們現在可以理解我為什麼老是對嚴謹的數學方法不太放心了。也許我應該提供一個比較嚴肅的理由。當你用太多嚴謹的數學時，你把你的注意力放在一些對物理而言不太重要的點上，而遠離了實驗的處境。反之若你用比較骯髒的數學方法，如同我經常做的，你將被迫專注在實驗的景況上；無論你寫下那一個式子，你都試著與真實世界作比對，如此一來將比用嚴謹數學更能接近事實的真相。”( 物理雙月刊第四十一卷, 台灣物理學會 , 2019年, 第78頁)
此外，我發現專注及不放棄在研究中是不可或缺的，它們常常帶來豐厚的收獲。因此我經常鼓勵學生們，去經歷在痛苦掙扎中做物理，最終得到結果時所伴隨的成就感。一旦嚐過其滋味，就必然久久不能忘懐。這讓我想到我們做物理就好像聖經所說的，“尋找它，如尋找銀子，搜求它，如搜求隱藏的珍寶”(箴言第二章第4節)。然而更重要是認識這些銀子和珍寳的主人，“你就明白敬畏耶和華，得以認識 神。因為，耶和華賜人智慧；知識和聰明都由他口而出。 ”(箴言第二章第5-6節)
My research area is high energy physics phenomenology. I do researches in flavor physics concerning the decays of heavy hadrons for years, and I also do some researches on dark matter recently. My main research works in these few years are as following.
I investigated the topological amplitude in hadronic decays using an SU(3) approach. It has the advantage of maintaining SU(3) symmetry and providing estimation on the relative sizes of different topological amplitudes at the same time. Well known results on topological amplitudes can be easily obtained, while the method can be used to study more complicated systems, such as systems involving baryons and pentaquarks. I and my collaborator made use of it to predict branching ratios of two-body baryonic B decays and pentaquark decays.
I studied the weak decay form factors of spin-1/2 and 3/2 heavy baryon using the light-front quark model. These form factors were used to predict branching ratios of some heavy baryon decay modes. This study involved rather complicated calculations. I needed to rederive almost all ingredients in the calculation, including correcting some errors in the literature. It was exciting to find that my results on the form factors agree reasonably well with the expectations of heavy quark symmetry.
On the research on dark matter, I and my collaborator investigated the Dirac fermionic dark matter systematically. We found that as implicated from the recent data, the masses of these dark matters have to be very large, and the Sommerfeld enhancement effect played critical role in achieving the above conclusion.
I used to collect advices of doing research from others. I found some of them useful.
Kun Huang： “Learning knowledge is not the more the better, the deeper the better, but to surrender to the application, to match your ability to handle knowledge。” (Kun Huang, Solid-state Physics, Peking University Press, 2009)
T. D. Lee： “If you have a right direction, it has its own logics. It is like you are excavating a monument .... If you are not doing something by force, you know it is good, and if you need to add a hypothesis on every step, it is not necessarily be reliable.” (Physics Bimonthly, vol. 14, issue 5, Physical Society of R.O.C., 1992, p.516)
E. Fermi: “When one does a theoretical calculation, you know, there are two ways of doing it. Either you should have a clear physical model in mind, or you should have a rigorous mathematical basis.” (according to F. Dyson’s recollection, https://www.webofstories.com/play/freeman.dyson/94)
Heisenberg： “I think that you understand now why I am always a bit sceptical of rigorous mathematical methods. Perhaps I should give a more serious reason for that: When you try too much for rigorous mathematical methods, you fix your attention on those points which are not important from the physics’ point and thereby you get away from the experimental situation. If you try to solve a problem by rather dirty mathematics, as I have mostly done, then you are forced always to think of the experimental situation; and whatever formulae you write down, you try to compare the formulae with reality and thereby, somehow, you get closer to reality than by looking for the rigorous methods. ” (From a Life of Physics, World Scientific Publishing Co. Pte. Ltd., Singapore, 1989, p.44)
In my research, I have more or less used the above advices. Huang Kun's advice helps me no longer bothered with books and papers which I have not read, or which I do not comprehend at all. T. D. Lee's advice reminds me to judge what I do is natural or not. When something is natural, I often feel as if it is always there, waiting for me to discover it. Since my research field is high-energy physics phenomenology, I need to keep good contact with experiments, therefore, I can easily agree with Fermi and Heisenberg.
In addition, I found that intense concentration and not giving up are essential in doing research, and they often yield great rewards. I often encourage students to go through the pain of struggle to finally obtain results in doing physics, as it is accompanied by a sense of accomplishment. Once tasted, it is bound to be forgotten for a long period of time. It reminds me that doing physics is like what the Bible said, “and if you look for it as for silver and search for it as for hidden treasure” (Proverbs, Chapter 2, verse 4, NIV), and, nevertheless, it is more important to know the owner of these silvers and hidden treasures, “ then you will understand the fear of the Lord and find the knowledge of God. For the Lord gives wisdom; from his mouth come knowledge and understanding.” (Proverbs, Chapter 2, verses 5-6, NIV).