arXiv subjects

Junquan Tao

Publications and source records attributed to Junquan Tao.

7 recordsLinked to original sources

arXiv2024

Extra Higgs boson searches at the LHC

Many searches for additional Higgs bosons, which are predicted by a lot of interesting models beyond the standard model, have been performed at the LHC. Some selected latest results of the searches for extra Higgs bosons at the LHC are presented. These additional Higgs bosons could be produced either directly from the parton interactions or from the decays of the observed standard model Higgs boson or a new heavier resonance. The searches used the data from proton-proton collisions delivered by the LHC at a centre-of-mass energy of $\sqrt{s}=13~\TeV$ and recorded with the ATLAS and CMS detectors. No direct evidence of new physics has been observed yet. Several mild excesses were observed in some final states. More data is needed to conclude on the nature of these excesses.

hep-ex↗

arXiv2018

Measurements of the 125 GeV Higgs boson at CMS

Results of the measurements of the 125 GeV Higgs boson properties with proton-proton collision data at $\sqrt{s}=13$ TeV collected by CMS detector are presented. The used Higgs boson decay channels include the five major decay modes, $\mathrm{H}\rightarrowγγ$, $\mathrm{H}\rightarrow{\rm Z}{\rm Z}\rightarrow4\ell$, $\mathrm{H}\rightarrow{\rm W}{\rm W}\rightarrow\ellν\ellν$, $\mathrm{H}\rightarrowτ^{+}τ^{-}$ and $\mathrm{H}\rightarrow b\bar{b}$, and two rare decay modes, $\mathrm{H}\rightarrowμ^{+}μ^{-}$ and $\mathrm{H}\rightarrow{\rm Z}/γ^{*}+γ\rightarrow\ell\ellγ$, with $\ell={\rm e},μ$. The measured Higgs boson properties include its mass, signal strength relative to the standard model prediction, signal strength modifiers for different Higgs boson production modes, coupling modifiers to fermions and bosons, effective coupling modifiers to photons and gluons, simplified template cross sections, fiducial cross sections. All results are consistent, within their uncertainties, with the expectations for the Standard Model Higgs boson.

hep-ex↗

arXiv2018

Search for a lighter Higgs Boson in the Next-to-Minimal Supersymmetric Standard Model

After the discovery of the Higgs boson with mass at approximately 125 $GeV$ at the LHC, many studies both from the theoretical and experimental sides have been performed to search for a new Higgs Boson lighter than the 125 $GeV$ Higgs boson. We explore the possibility of constraining a lighter neutral scalar Higgs boson $h_{1}$ and a lighter pseudo-scalar Higgs boson $a_{1}$ in the Next-to-Minimal Supersymmetric Standard Model by restricting the next-to-lightest scalar Higgs boson $h_{2}$ to be the LHC observed Higgs boson after the phenomenological constraints and the constraints from experimental measurements. Such lighter particles are not yet completely excluded by the latest results of the search for a lighter Higgs boson with the diphoton decay channel from LHC data. Our results show that for a lighter scalar Higgs boson some new constraints on the Next-to-Minimal Supersymmetric Standard Model could be obtained at the LHC if such a search is performed by the experimental collaborations with more data. The discovery potential of other interesting decay channels of such a lighter neutral scalar and a pseudo-scalar particle are also discussed.

hep-ph↗

arXiv2017

Search for rare and exotic Higgs Boson decay modes

The latest results in the search for rare and exotic Higgs boson decays in proton-proton collision events collected with the CMS detector at the LHC are presented. The searches are performed for several decay modes of Higgs boson including $\mathrm{H}\rightarrow{\rm X (X \rightarrow2\ell)γ}$ ($X= {\rm Z}, γ^* $ and $\ell={\rm e},μ$), $\mathrm{H}\rightarrow{ μμ/ {\rm e}{\rm e}}$, invisible decays, lepton flavour violating decays and Higgs decay to light scalars or pseudo-scalars. No hint for new physics has been found from the analyzed results with the full LHC run-1 data collected during 2011 and 2012 at $\sqrt{s}=7-8$ TeV and with the run-2 data at $\sqrt{s}=13$ TeV collected during 2015 and 2016. Limits are set for all the searches which have been performed by CMS.

hep-ex↗

arXiv2017

Higgs boson measurements in high resolution channels with CMS

The latest measurements of the Higgs boson properties in both the $\mathrm{H}\rightarrowγγ$ decay channel and the $\mathrm{H}\rightarrow{\rm Z}{\rm Z}\rightarrow4\ell$ ($\ell={\rm e},μ$) decay channel using the proton-proton collision data corresponding to an integrated luminosity of 35.9 $\mathrm{fb}^{-1}$ at $\sqrt{s}=13$ $TeV$, including the signal strength relative to the standard model prediction, signal strength modifiers for different Higgs production modes, coupling modifiers to fermions and bosons, and effective coupling modifiers to photons and gluons, are presented. In addition, dedicated measurements of the Higgs boson's mass, width, total and differential fiducial cross sections have been summarized. All results are consistent, within their uncertainties, with the expectations for the SM Higgs boson.

hep-ex↗

arXiv2016

Search for a lighter Higgs in Two Higgs Doublet Models

We consider present constraints on Two Higgs Doublet Models, both from the LHC at Run 1 and from other sources in order to explore the possibility of constraining a neutral scalar or pseudo-scalar particle lighter than the 125 GeV Higgs boson. Such a lighter particle is not yet completely excluded by present data. We show with a simplified analysis that some new constraints could be obtained at the LHC if such a search is performed by the experimental collaborations, which we therefore encourage to continue carrying out light diphoton resonance searches at $\sqrt{s}=$ 13 TeV in the context of Two Higgs Doublet Models.

hep-ph↗

arXiv2015

Production of γγ+ 2jets from double parton scattering in proton-proton collisions at the LHC

Cross sections for the production of pairs of photons plus two additional jets produced from double parton scattering in high-energy proton-proton collisions at the LHC are calculated for the first time. The estimates are based on the theoretical perturbative QCD predictions for the productions of γγat next-to-next-to-leading-order, jet + jet and γ+ jet at next-to-leading-order, for their corresponding single-scattering cross sections. The cross sections and expected event rates for γγ+ 2 jets from double parton scattering, after typical acceptance and selections, are given for proton-proton collisions with the center-of-mass energies of 13 TeV and an integrated luminosity of 100 fb-1 planned for the following two years, and also center-of-mass energies of 14 TeV with 3000 fb-1 of integrated luminosity as LHC designed.

hep-ph↗