DSpace community: 理學院

Estimation of Fake Hadronic Tau Lepton Background in the HH → bbττ LepHad Channel Using Run 2 and Run 3 Data with the ATLAS Detector

Fri, 06 Mar 2026 11:19:25 GMT

title: Estimation of Fake Hadronic Tau Lepton Background in the HH → bbττ LepHad Channel Using Run 2 and Run 3 Data with the ATLAS Detector abstract: 本研究提出一種以資料為基礎的方法，用於估計 ????→????????過程中假強子衰變 ?? 輕子背景，並著重於輕子–強子（??lep??had）道的分析。對希格斯玻色子對產生的搜尋具有特別重要的意義，因為此類研究能直接探測希格斯自耦合，並對標準模型進行關鍵檢驗。本文使用 ATLAS 偵測器在 Run 2 期間所量測、對應質心能量 √??=13TeV 的質子–質子對撞資料，以及 2022 至 2023 年 Run 3 所收集、質心能量 √??=13.6TeV 的可用資料。在 ATLAS 中，?? 輕子僅能透過其可見衰變產物加以重建，而涉及強子衰變 ?? 輕子的分析，特別容易受到由夸克與膠子噴注被誤辨識為 ??had 候選體所造成的背景影響。為了刻畫這些貢獻，本文採用 Fake Factor 方法，在富含 ????ˉ 與多噴注事例的控制區中量測 fake factor，並將其套用至訊號區。透過專門設計的 closure 測試對該方法進行驗證，結果顯示在兩個 run 期間，預測與實測資料之間具有良好的一致性，確認了假背景估計的穩健性。 ;This study presents a data-driven estimation of fake hadronic τ-lepton backgrounds in the HH → bbττ process, focusing on the lepton–hadronic (τlepτhad) channel. The search for Higgs-boson pair production is of particular importance, as it provides direct sensitivity to the Higgs self-coupling and offers a critical test of the Standard Model. The analysis uses proton–proton collision data recorded by the ATLAS detector during Run 2 at √s = 13 TeV and available Run 3 data collected in 2022 to 2023 at √s = 13.6 TeV. In ATLAS, τ leptons are reconstructed only through their visible decay products, and analyses involving hadronically decaying τ leptons are especially affected by backgrounds from quark- and gluon initiated jets misidentified as τhad candidates. To model these contributions, a Fake Factor Method is employed, with fake factors derived in control regions enriched in t¯tand multijet events and subsequently applied to the signal region. The method is validated through dedicated closure tests, demonstrating good agreement between the prediction and observed data across both run periods, thereby confirming the robustness of the fake-background estimation

配對交易策略：價差、共整合與Copula方法;Pairs Trading Strategies: Spread, Cointegration, and Copula Approaches

Fri, 06 Mar 2026 10:58:02 GMT

title: 配對交易策略：價差、共整合與Copula方法;Pairs Trading Strategies: Spread, Cointegration, and Copula Approaches abstract: 本研究以配對交易為核心，比較共整合法、價差法、二元 Copula與納入隱含波動率資訊的階層式 Copula 交易訊號於投資績效上的差異，並著重在階層式模型是否有助於提升二元模型之績效表現。其中配對組合透過共整合檢定篩選，並以總再投資報酬率作為長期績效衡量指標。實證結果顯示，共整合法、價差法長期持有、低頻交易中產生正報酬。而Copula策略能頻繁捕捉短期資產價格偏離，且階層式模型能改善二元模型績效表現，並在敏感度測試中階層式模型之績效表現皆有改善。;This study adopts pairs trading as its core framework and systematically compares the investment performance of cointegration-based strategies, spread-based strategies, bivariate Copula models, and hierarchical Copula trading signals that incorporate implied volatility information. The analysis focuses in particular on whether the hierarchical Copula structure can effectively enhance the performance of conventional bivariate Copula models. Trading pairs are selected through cointegration tests, and total reinvested return is employed as the primary measure of long-term performance. The empirical results indicate that cointegration and spread-based strategies generate positive returns under long-horizon, low-frequency trading structures. In contrast, Copula-based strategies are more effective in capturing short-term price deviations between assets. Moreover, the hierarchical Copula model consistently improves upon the performance of the bivariate Copula model, with robustness and sensitivity analyses further confirming the superior and more stable performance of the hierarchical framework.

有機發光二極體中載子調控結構與材料選擇對發光效能之探討;Carrier Regulation Structures and Material Selection for Improved Emission Performance of Organic Light-Emitting Diodes

Fri, 06 Mar 2026 10:48:23 GMT

title: 有機發光二極體中載子調控結構與材料選擇對發光效能之探討;Carrier Regulation Structures and Material Selection for Improved Emission Performance of Organic Light-Emitting Diodes abstract: 本研究以有機發光二極體(Organic Light-Emitting Diode, OLED)為研究主軸，系統性探討電子注入層、電洞阻擋層、電洞調控層以及主體/客體材料選擇對元件電性與發光效率之影響。研究中採用Super Yellow(SY)、PFO、CBP以及一系列 D2-nPh材料作為發光或主體材料，並透過元件結構與材料參數之調控，逐步建立高效率OLED元件架構。首先，比較不同電子注入層材料之影響，結果顯示相較於LiF，Li₂CO₃可有效改善電子注入行為，使元件展現較佳之操作電壓與發光效率，因而被選定為後續元件之電子注入層。接著，探討不同電洞阻擋層(Hole Blocking Layer, HBL)材料對元件效能之影響，比較TmPyPB、BCP與BP4mPy後發現，TmPyPB能有效侷限電子並改善載子平衡，使SY與PFO元件之外部量子效率(External Quantum Efficiency, EQE)顯著提升，並成為後續研究中主要採用之HBL材料。在完成電子注入層與電洞阻擋層之篩選後，進一步引入聚乙烯咔唑(poly(9-vinylcarbazole), PVK)作為電洞調控層。PVK之LUMO能階可有效阻擋電子穿越主動層，而其HOMO能階亦可與CBP與PFO形成較佳之能階匹配，使元件整體載子平衡與發光效率獲得改善。隨後，在相同且已最佳化之元件架構下，比較不同主體材料之表現，結果顯示雖然SY具備較高之發光效率，但其與PVK之能階匹配較差；相對而言，D2-4Ph在效率與操作電壓上展現出較佳之整體穩定性。為進一步分析D2-nPh系列材料之差異，本研究製作單電洞元件，並以空間電荷限制電流(Space-Charge-Limited Current, SCLC)模型分析其電洞遷移率。結果顯示 D2-4Ph具有最高之電洞遷移率，且其OLED元件亦表現出相對較佳之發光效率。在主體/客體摻雜元件方面，本研究將2DIndFL-PT、DIndFL-2-BTAQ與 DIndFL-TTp-Tp-1-C6BTABTD等客體材料分別摻入D2-4Ph、CBP、PFO與SY主體中，探討摻雜濃度對元件效能之影響。結果顯示，適當摻雜可有效提升元件EQE，而過高濃度則因能量轉移效率下降與非輻射淬滅效應增加，導致效率降低。特別是在SY主體中，摻雜近紅外客體材料後之EQE普遍低於純SY元件，主要歸因於主體發光光譜與客體吸收光譜重疊不足，使能量轉移效率受限。最後，本研究以D2-4Ph為主體材料，透過摻雜SY並調控其濃度，成功實現白光OLED元件。結果顯示，雖然較高SY濃度可提升發光效率，但在色溫表現上，低至中等濃度之SY摻雜更接近理想白光範圍，顯示在效率與色度之間需取得適當平衡。綜合上述研究結果，本研究證實透過電子注入層與電洞阻擋層之適當選擇、PVK電洞調控層之引入、主體/客體材料能階與光譜匹配，以及材料載子遷移率之最佳化，可有效提升OLED元件之發光效率與電性表現，對未來高效率有機發光材料與元件設計具有重要參考價值。 ;This study focuses on organic light-emitting diodes (OLEDs) and systematically investigates the effects of electron injection layers, hole blocking layers (HBLs), hole modulation layers, and host–guest material selection on device electrical characteristics and emission efficiency. Super Yellow (SY), PFO, CBP, and a series of D2-nPh materials were employed as emissive or host materials. Through step-by-step optimization of device architecture and material parameters, high-performance OLED structures were established. First, the influence of different electron injection layers was examined. Compared with LiF, Li₂CO₃ exhibited superior electron injection behavior, leading to lower operating voltage and improved device efficiency. Consequently, Li₂CO₃ was selected as the electron injection layer for subsequent devices. The effects of various hole blocking layer materials, including TmPyPB, BCP, and BP4mPy, were then evaluated. Among them, TmPyPB effectively confined electrons and improved carrier balance, resulting in significantly enhanced external quantum efficiency (EQE) in both SY- and PFO-based devices, and was therefore adopted in later studies. After optimizing the electron injection and hole blocking layers, poly(9-vinylcarbazole) (PVK) was introduced as a hole modulation layer. The LUMO level of PVK effectively suppresses electron leakage through the emissive layer, while its HOMO level provides favorable energy level alignment with CBP and PFO, leading to improved carrier balance and device performance. Under the same optimized device architecture, different host materials were then compared. Although SY exhibited high emission efficiency, its energy level alignment with PVK was less favorable. In contrast, D2-4Ph demonstrated more stable performance with a favorable balance between efficiency and operating voltage. To further elucidate the intrinsic material properties of the D2 series, hole-only devices were fabricated and analyzed using the space-charge-limited current (SCLC) model. Among the D2-nPh materials, D2-4Ph exhibited the highest zero-field hole mobility, which correlated well with its superior OLED performance. In the host–guest doping studies, 2DIndFL-PT, DIndFL-2-BTAQ, and DIndFL-TTp-Tp-1-C6BTABTD were incorporated into D2-4Ph, CBP, PFO, and SY host materials to investigate the influence of doping concentration on device performance. The results show that appropriate guest doping significantly enhances EQE, while excessive doping leads to reduced efficiency due to decreased energy transfer efficiency and increased non-radiative quenching. In particular, SY-based devices doped with near-infrared emitters exhibited lower EQE than pristine SY devices, primarily due to insufficient spectral overlap between the host emission and guest absorption, limiting energy transfer efficiency. Finally, white OLEDs were realized using D2-4Ph as the host material with SY as a complementary emitter. By tuning the SY doping concentration, both emission efficiency and correlated color temperature (CCT) could be modulated. Although higher SY concentrations yielded higher EQE, lower to moderate doping concentrations provided CCT values closer to ideal white light, indicating a trade-off between efficiency and color quality. Overall, this study demonstrates that proper selection of electron injection layers and hole blocking layers, introduction of PVK as a hole modulation layer, optimization of host–guest energy level alignment and spectral overlap, and enhancement of charge carrier mobility are critical factors for improving OLED efficiency and electrical performance. These findings provide valuable insights for the design of high-efficiency organic emissive materials and OLED devices.

光子對與乙炔氣體的動態交互作用;Dynamic Interaction Behavior Between Photon Pairs AndAcetylene Gas

Fri, 06 Mar 2026 10:47:57 GMT

title: 光子對與乙炔氣體的動態交互作用;Dynamic Interaction Behavior Between Photon Pairs AndAcetylene Gas abstract: 我們研究了分子吸收與量子光傳播之間的交互作用，重點聚焦於單光子層級下的快光（fast-light）現象。從量子觀點出發，我們推導了吸收譜線的形成機制，並在符合因果律的條件下，模擬了由反常色散所引起的脈衝前移效應。在實驗方面，透過自發參數下轉換（SPDC）所產生的單光子脈衝，其頻譜被調整至與乙炔分子的吸收線對齊，成功觀察到不違反因果律的可測負群延遲（negative group delay）。作為前置步驟，我們亦分析了 SPDC 雙光子訊號的訊噪比（SNR），以確定最佳操作條件。此外，本研究也指出，快光效應可望藉由有效負折射率提升光學陀螺儀的靈敏度。;We investigate the interaction between molecular absorption and quantum light propagation, focusing on the fast-light phenomenon at the single-photon level. From a quantum perspective, we derived the formation mechanism of absorption lines and simulated pulse advancement induced by anomalous dispersion under causality. Experimentally, single-photon pulses generated via spontaneous parametric down conversion(SPDC) were spectrally aligned with an acetylene absorption line, enabling the observation of measurable negative group de lays without violating causality. As a preparatory step, the signal-to-noise ratio (SNR) of SPDC biphotons was analyzed to determine the optimal operating regime. The potential application of fast light in enhancing optical gyroscope sensitivity via an effective negative refractive index is also highlighted.