In the light of the 125 GeV Higgs ($h$) discovery at the Large Hadron Collider (LHC), one of the primary goals of the LHC and possible future colliders is to understand its interactions more precisely. Here we have studied the $h$-$b$-$\bar b$-$γ$ effective interaction terms arising out of gauge invariant dimension six operators in a model independent setting, as a potential source of new physics. Their role in some detectable final states have been compared with those coming from anomalous $h$-$b$-$\bar b$ interactions. We have considered the bounds coming from the existing collider and other low energy experimental data in order to derive constraints on the potential new physics couplings and predict possible collider signals for the two different new physics scenarios in the context of 14 TeV LHC and and a future $e^+e^-$ machine. We conclude that the anomalous $h$-$b$-$\bar b$-$γ$ coupling can be probed at the LHC at 14 TeV at the 3$σ$ level with an integrated luminosity of $\sim 2000~{\rm fb}^{-1}$, which an $e^+e^-$ collider can probe at the 3$σ$ level with $\sim 12(7)~{\rm fb}^{-1}$ at $\sqrt{s}=250(500)~{\rm GeV}$. It is also found that anomalous $h$-$b$-$\bar b$ interactions, subject to the existing LHC constraints, can not compete with the rates driven by $h$-$b$-$\bar b$-$γ$ effective interactions.
The discovery potential of both singlet and doublet vector-like leptons (VLLs) at the Large Hadron Collider (LHC) as well as at the not-so-far future muon and electron machines is explored. The focus is on a single production channel for LHC direct searches while double production signatures are proposed for the leptonic colliders. A Deep Learning algorithm to determine the discovery (or exclusion) statistical significance at the LHC is employed. While doublet VLLs can be probed up to masses of 1 TeV, their singlet counterparts have very low cross sections and can hardly be tested beyond a few…
The cross section for exclusive $Υ$ ultraperipheral photoproduction at present and future colliders is determined using the low $x$ gluon PDF extracted from an analysis of exclusive $J/ψ$ measurements performed at HERA and the LHC. Predictions are given at next-to-leading order in collinear factorisation over a wide $γp$ centre-of-mass energy range, calculated assuming the non-relativistic approximation for the $Υ$ wave function, and with skewing corrections incorporated.
We present cross-section expectations for various processes and collider options, for benchmark scenarios of the Inert Doublet Model, a Two Higgs Doublet Model with a dark matter candidate. The proposed scenarios are consistent with current dark matter constraints, including the most recent bounds from the XENON1T experiment and relic density, as well as with known collider and low-energy limits. These benchmarks, chosen in earlier work for studies at $e^+e^-$ colliders, exhibit a variety of kinematic features that should be explored at current and future runs of the LHC. We provide cross sect…
Search for Dark Matter in 2HDMS at LHC and future Lepton Colliders
University of Oklahoma（奥克拉荷马大学）；The Institute of Mathematical Sciences（数学科学研究所）；Shenzhen Campus of Sun Yat-Sen University（中山大学深圳校区）；Universität Hamburg（汉堡大学）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器中心）
Photoproduction of $ρ^0$ mesons in ultraperipheral heavy ion collisions at energies available at the BNL Relativistic Heavy Ion Collider (RHIC) and CERN Large Hadron Collider (LHC)
We introduce a numerical package FORward Experiment SEnsitivity Estimator, or FORESEE, that can be used to simulate the expected sensitivity reach of experiments placed in the far-forward direction from the proton-proton interaction point. The simulations can be performed for $14$ TeV collision energy characteristic for the LHC, as well as for larger energies: $27$ and $100$ TeV. In the package, a comprehensive list of validated forward spectra of various SM species is also provided. The capabilities of FORESEE are illustrated for the popular dark photon and dark Higgs boson models, as well as…
Large fermionic multiplets appear in different extensions of the Standard Model (SM), which are essential to predict small neutrino masses, relic abundance of the dark matter (DM) and the measured value of muon anomalous magnetic moment (muon (g-2)). Models containing quintuplet of fermions ($Σ$), along with other scalar multiplets, can address recent anomalies in the flavor sector while satisfying the constraints from the electroweak physics. In standard scenarios, the exotic fermions couple with the SM particles directly and there exists a strong limit on their masses from collider experimen…
The study of the Higgs boson properties offers compelling perspectives for testing the effects of physics beyond the Standard Model and has deep implications for the LHC program and future colliders. Accurate determinations of the Higgs boson properties can provide us with a distinctively precise picture of the Higgs sector, set tight bounds, and predict ranges for the values of new physics model parameters. In this paper, we discuss the constraints on supersymmetry that can be derived by a determination of the Higgs boson mass and couplings. We quantify these constraints by using scans of the…
A Boost to $h \to Z γ$: from LHC to Future $e^+ e^-$ Colliders
在大型强子对撞机上精确测量希格斯粒子的$h \to Z γ$衰变是非常具有挑战性的，因为SM $h \to Z γ\, (Z \to \ell \ell)$的分支分数很低，而且缺少运动学处理来抑制大的SM $Z γ$背景。我们将展示如何通过考虑与硬喷流相关的希格斯生产来显着改善这种测量。我们将该通道中的预期HL-LHC灵敏度与$h$相当增强的其他Higgs产生模式进行了比较，例如~弱玻色子融合，以及未来$e^{+}e^{-}$圆形对撞机（{ \sl fcc-ee}）可实现的潜在$h \to Z γ$测量。最后，我们讨论了新的物理意义的精确测量的$h \to Z γ$。
If the masses of at least two generations of right-handed neutrinos (RHNs) are near-degenerate, the scale of leptogenesis can be as low as $\sim$ 100 GeV. In this work, we study probing such resonant leptogenesis in the $B-L$ model at the LHC and future multi-TeV muon colliders via the process $Z'\to NN\to\ell^\pm\ell^\pm+{\rm jets}$, with $Z'$ the $U(1)_{B-L}$ gauge boson and $N$ the RHN. The same-sign dilepton feature of the signal makes it almost background-free, while the event number difference between positive and negative leptons is a hint for $CP$ violation, which is a key ingredient o…
Probing the anomalous electromagnetic dipole moments of the top quark in $γp$ collision at the LHC, the HL-LHC and the HE-LHC
确定顶夸克的电磁偶极矩是对撞机实验中顶夸克物理计划的重要目标之一。为此，我们讨论了在大型强子对撞机（LHC）、高亮度大型强子对撞机（HL-LHC）和高能大型强子对撞机（HE-LHC）上通过过程$pp\rightarrow p γp \rightarrow p t \bar{t} X$产生顶夸克对来研究顶夸克电、磁偶极矩的敏感性。我们应用纯轻子和半轻子衰变研究末态顶夸克对的产生。此外，我们考虑了系统的不确定性的$0,3\%$和$5\%$。从过程$pp\rightarrow p γp \rightarrow p t \bar{t} X$获得的关于异常$a_{A}$和$a_{V}$偶联的最佳限度是$|a_{A}|=0.0200$和$a_{V}=[-0.9959; 0.0003]$。因此，我们的结果表明，$pp\rightarrow p γp \rightarrow p t \bar{t} X$过程是一个很好的前景探测顶夸克的电和磁偶极矩在HL-LHC和HE-LHC。
Several experimental measurements of $B$ meson decays, in tension with Standard Model predictions, exhibit large sources of Lepton Flavour Universality violation. We perform an analysis of the effects of the global fits to the Wilson coefficients assuming a model independent effective Hamiltonian approach, by including a proposal of different scenarios to include the New Physics contributions. Both the current fits at the LHC and the ILC projections are considered. We found that for a simultaneous analysis of predictions for the $R_{D^{(*)}}$ and $R_{K^{(*)}}$ observables, the scenarios with t…
