arXiv subjects

Chenyu Fang

Publications and source records attributed to Chenyu Fang.

3 recordsLinked to original sources

arXiv2025

Enhanced Charged Higgs Signal at the LHC

We investigate the discovery prospects of a charged Higgs boson ($H^\pm$) at the Large Hadron Collider (LHC) via the process $cg\to bH^\pm \to bc\bar{b}$ within the framework of a general two Higgs doublet model (G2HDM). In most two Higgs doublet models, the $H^+ cb$ coupling ($g_{H^+cb}$) is usually suppressed by the CKM matrix element $V_{cb}$. In G2HDM, there are additional Yukawa couplings, the process $cg\to bH^\pm \to bc\bar{b}$ is enhanced by the coupling $g_{H^+cb} \simeq \rtc V_{tb}$ in both the production and decay of the charged Higgs boson. We study possible physics backgrounds and evaluate the discovery potential with realistic acceptance cuts and tagging efficiencies at collider energies of $\sqrt{s}=$13 and 14 TeV. We apply $b$-tagging and $c$-tagging and show that $m_{H^+}$ can be extracted by pairing the tagged $b$ and $c$-jets. Our analysis leads to promising results for the current LHC and expected high-luminosity LHC.

hep-ph↗

arXiv2025

Charming top interactions with a neutral Higgs Boson decaying into $\tau^+ \tau^-$ at the LHC

We investigate the discovery potential of flavor changing neutral Higgs (FCNH) interactions in top quark decays at the LHC. A general two Higgs doublet model (2HDM) is adopted to study the top quark decay $t \to c \phi^0$, where $\phi^0$ is either a CP-even heavy neutral scalar ($H^0$), or a CP-odd pseudoscalar ($A^0$), followed by the Higgs boson decaying into $\tau^+\tau^-$. The complete process is $pp \to t\bar{t} \to t c\phi^0 \to (bjj) (c\tau_{lep}\tau_{had}) +X$, where $t$ or $\bar{t}$ become virtual when $m_{\phi} > m_t -m_c$, $\tau_{lep}$ and $\tau_{had}$ represent the $\tau$ leptonic decay ($\tau^\pm \to \ell^\pm$ + MET) and the $\tau$ hadronic decay ($\tau^\pm \to j_\tau$ + MET), respectively. We evaluate the cross section applying realistic selection criteria for the FCNH signal and the dominant physics background at the parton-level. In addition, we employ \textsc{MadGraph}, \textsc{Pythia}~8, and \textsc{Delphes} to perform a realistic event-level Monte Carlo simulation analysis. The collinear approximation is applied since the $\tau$'s from Higgs boson decays are highly boosted such that $\tau_{lep}$ and $\tau_{had}$ momenta are approximately in the same direction as the $\tau$'s, which enables the reconstruction of the Higgs boson mass. The energy of the charm quark provides an additional kinematic variable that discriminates the signal from the background. In the alignment limit, the FCNH couplings for the heavy Higgs bosons ($H^0$ and $A^0$) will not be suppressed [$\lambda_{tcH} \propto \sin(\beta-\alpha) \approx 1$]. We study the discovery potential for the heavy neutral Higgs bosons at the LHC with collider energies of $\sqrt{s} = 13$ TeV, 13.6 TeV and 14 TeV, and find the High-Luminosity LHC offers great promise for the discovery of heavier Higgs bosons from $t \to c \phi^0$ or $t^* \to c \phi^0$.

hep-ph↗

arXiv2024

PlanGPT: Enhancing Urban Planning with Tailored Language Model and Efficient Retrieval

In the field of urban planning, general-purpose large language models often struggle to meet the specific needs of planners. Tasks like generating urban planning texts, retrieving related information, and evaluating planning documents pose unique challenges. To enhance the efficiency of urban professionals and overcome these obstacles, we introduce PlanGPT, the first specialized Large Language Model tailored for urban and spatial planning. Developed through collaborative efforts with institutions like the Chinese Academy of Urban Planning, PlanGPT leverages a customized local database retrieval framework, domain-specific fine-tuning of base models, and advanced tooling capabilities. Empirical tests demonstrate that PlanGPT has achieved advanced performance, delivering responses of superior quality precisely tailored to the intricacies of urban planning.

cs.CL↗