A First Look at the Impact of NNNLO Theory Uncertainties on Top Mass Measurements at the ILC
Frank Simon
备注：
6 pages, 4 figures, Talk presented at the International Workshop on Future Linear Colliders (LCWS15), Whistler, Canada, 2-6 November 2015; v3 corrected plotting problem in Fig 1 and figure label typos
A scan of the top production threshold at a future electron-positron collider provides the possibility for a precise measurement of the top quark mass in theoretically well-defined mass schemes. With statistical uncertainties of 20 MeV or below, systematics will likely dominate the total uncertainty of the measurement. This contribution presents a first look at the impact of the renormalization scale uncertainties in recent NNNLO calculations of the top pair production cross section in the threshold region on the measurement of the top quark mass at the International Linear Collider.
This note presents an analysis of the potential of future high-energy electron-positron colliders to measure the $b$-quark mass. We perform a full-simulation study of the measurement of the ratio of the three-jet rates in events with $b\bar{b}(g)$ and $q\bar{q}(g)$ production, $R_{3}^{bl}$, and assess the dominant uncertainties, including theory and experimental systematic uncertainties. We find that the ILC "Higgs factory" stage, with an integrated luminosity of 2 ab$^{-1}$ at $\sqrt{s}=$ 250 GeV can measure the $b-$quark $bar{MS}$ mass at a scale of 250 GeV ($m_b(250~$GeV$)$) with a precisio…
The $e^+e^- \to HZ$ process with the subsequent decay of the Higgs boson $H \to Zγ$ is studied, where both $Z$ bosons are reconstructed in the final states with two jets. The analysis is performed using Monte Carlo data samples obtained with detailed ILD (The International Large Detector) detector simulation assuming an integrated luminosity of 2 ab$^{-1}$, beam polarizations of ${\cal{P}}_{e^-e^+} = (-0.8, +0.3)$, and center-of-mass energy of $\sqrt{s}$ = 250 GeV. The analysis is repeated for the case of two 0.9 ab$^{-1}$ data samples with polarizations ${\cal{P}}_{e^-e^+} = (\mp0.8, \pm0.3)$…
LEP precision on electroweak measurements was sufficient not to hamper the extraction of Higgs couplings at the LHC. But the foreseen permille-level Higgs measurements at future lepton colliders might suffer from parametric electroweak uncertainties in the absence of a dedicated electroweak program. We perform a joint, complete and consistent effective-field-theory analysis of Higgs and electroweak processes. The full electroweak-sector dependence of the $e^+e^- \to WW$ production process is notably accounted for, using statistically optimal observables. Up-to-date HL-LHC projections are combi…
Impact of quark flavor violation on the decay $h^0(125GeV) \to c\bar{c}$ in the MSSM
在$\overline{\rm DR}$重整化方案下，计算了含夸克味破坏（QFV）的MSSM中$h^0 \to c \bar{c}$的衰变宽度.我们研究了$\tilde{c}-\tilde{t}$混合的影响，考虑到从B介子数据的QFV的约束。我们发现，完整的单圈校正的衰减宽度$Γ(h^0 \to c \bar{c})$是非常敏感的MSSM QFV参数。在$\tilde{c}_{L,R}-\tilde{t}_{L,R}$混合较大的情况下，$Γ(h^0 \to c \bar{c})$可以与其SM值相差多达$\sim \pm 35\%$。在估计了宽度的不确定性之后，我们得出结论，在未来的$e^+ e^-$对撞机如ILC上观察这些QFV超对称效应是可能的。
The proposed Circular Electron Positron Collider (CEPC), with a center-of-mass energy $\sqrt{s} = 240$ GeV, will primarily serve as a Higgs factory. At the same time, it can offer good opportunities to search for new physics phenomena at low energy, which can be challenging to discover at hadron colliders, but well motivated by some theoretical models developed to explain, e.g., the relic abundance of dark matter. This paper presents sensitivity studies of chargino pair production, considering scenarios for both a Bino-like and a Higgsino-like neutralino as the lightest supersymmetric particle…
