arXiv subjects

Xinchou Lou

Publications and source records attributed to Xinchou Lou.

24 records · Page 2Linked to original sources

arXiv2016

Study of BESIII electromagnetic calorimeter performance with radiative lepton pair events

We study the photon detection efficiency and position resolution of the electromagnetic calorimeter (EMC) of the BESIII detector. The control samples of the initial-state-radiation (ISR) process of $e^+e^-\rightarrow γμ^+μ^-$ at $J/ψ$ and $ψ(3770)$ resonances are used for the calibration of the photon cluster shapes and photon detection efficiency study. The photon detection efficiency is defined as the fraction of predicted photon, determined by performing a kinematic fit with the four momenta of two charged tracks only, matched with the actual photons in the EMC. The spatial resolution of the EMC is studied in polar ($θ$) and azimuthal ($ϕ$) angle directions in a cylindrical coordinate system centered at the interaction point, with z-axis along the beam direction.

hep-ex↗

arXiv2015

Search for low-mass Higgs and dark photons at BESIII

Many extensions of the Standard Model introduce a new type of weak-interacting degrees of freedom. These models are motivated by the results of recent experimental anomalies. Typical models, such as Next-to-Minimal Supersymmetric Standard Model and Light Hidden Dark-sector Model, introduce the possibilities of low-mass Higgs and dark bosons. The masses of such particles are expected to be few GeV and thus making them accessible at BESIII experiment, an $e^+e^-$ collider experiment running at tau-charm region. This report summarizes the recent results of low-mass Higgs and dark bosons searches at BESIII.

hep-ex↗

arXiv2015

Concept for a Future Super Proton-Proton Collider

Following the discovery of the Higgs boson at LHC, new large colliders are being studied by the international high-energy community to explore Higgs physics in detail and new physics beyond the Standard Model. In China, a two-stage circular collider project CEPC-SPPC is proposed, with the first stage CEPC (Circular Electron Positron Collier, a so-called Higgs factory) focused on Higgs physics, and the second stage SPPC (Super Proton-Proton Collider) focused on new physics beyond the Standard Model. This paper discusses this second stage.

physics.acc-ph↗

arXiv2015

Study of photon detection efficiency and position resolution of BESIII electromagnetic calorimeter

We study the photon detection efficiency and position resolution of the electromagnetic calorimeter (EMC) of the BESIII experiment. The control sample of the initial-state-radiation (ISR) process of $e^+e^-\rightarrow γμ^+μ^-$ is used at $J/ψ$ and $ψ(3770)$ resonances for the EMC calibration and photon detection efficiency study. Photon detection efficiency is defined as the predicted photon, obtained by performing a kinematic fit with two muon tracks, matched with real photons in the EMC. The spatial resolution of the EMC is defined as the separation in polar ($θ$) and azimuthal ($ϕ$) angles between charged track and associated cluster centroid on the front face of the EMC crystals.

hep-ex↗

arXiv2015

Physics cross sections and event generation of $e^+e^-$ annihilations at the CEPC

The cross sections of the Higgs production and the corresponding backgrounds of $e^+e^-$ annihilations at the CEPC (Circular Electron and Positron Collider) are calculated by a Monte-Carlo method, and the beamstruhlung effect at the CEPC is carefully investigated. The potential for new physics beyond the Standard Model at the CEPC is discussed.

hep-ex↗

arXiv2015

Study of the Beamstrahlung Effects at the CEPC

The discovery of a 125 GeV Higgs boson at the LHC marked a breakthrough in particle physics. The relative lightness of the new particle inspires the consideration of a high luminosity Circular Electron Positron Collider (CEPC) as a Higgs Factory to study the Higgs boson in a clean environment. At the CEPC, the beamstrahlung might represent one of the most important sources of beam-induced backgrounds that will impact the detector. It will introduce additional backgrounds to the CEPC detector through the subsequent electron-positron pair production and the hadronic process. Therefore its impacts should be carefully evaluated. In this paper, the beamstrahlung-induced backgrounds are first estimated with analytical methods and are further evaluated in detail with Monte Carlo simulation. The detector occupancy due to the beamstrahlung at the location where the first vertex detector layer may be placed is found to be well below 0.5%. Radiation levels characterised as non-ionising energy loss (NIEL) and total ionising dose (TID) are estimated to be ~ $10^{11} 1 $ MeV $ n_{eq}/cm^2/$yr and ~ 300 kRad/yr, respectively.

physics.acc-ph↗