CaltechAUTHORS: Monograph
https://feeds.library.caltech.edu/people/Zhu-Ren-Yuan/monograph.rss
A Caltech Library Repository Feedhttp://www.rssboard.org/rss-specificationpython-feedgenenFri, 01 Nov 2024 19:34:15 -0700Inorganic Scintillators for Future HEP Experiments
https://resolver.caltech.edu/CaltechAUTHORS:20220504-151242643
Year: 2022
DOI: 10.48550/arXiv.2203.06731
Future HEP experiments at the energy and intensity frontiers present stringent challenges to inorganic scintillators in radiation tolerance, ultrafast time response and cost. This paper reports recent progress in radiation hard, ultrafast, and cost-effective inorganic scintillators for future HEP experiments. Examples are LYSO crystals for a precision time of flight detector, LuAG ceramics for an ultracompact, radiation hard shashlik sampling calorimeter, BaF₂:Y crystals for an ultrafast calorimeter, and cost-effective scintillators for a homogeneous hadron calorimeter. Applications for Gigahertz hard X-ray imaging will also be discussed.https://resolver.caltech.edu/CaltechAUTHORS:20220504-151242643Ultrafast Inorganic Crystals with Mass Production Capability for Future High-Rate Experiments
https://resolver.caltech.edu/CaltechAUTHORS:20220510-165800495
Year: 2022
DOI: 10.48550/arXiv.2203.06788
Future HEP experiments present stringent challenges to inorganic scintillators in both fast timing response and radiation tolerance. This paper reports recent progress in developing ultrafast inorganic scintillators with sub-ns decay time for future precision timing detectors and high-rate experiments. Performance of fast and ultrafast crystals with mass production capability are compared to CsI crystals which are used for the Mu2e calorimeter. Examples are LYSO:Ce, BaF₂ and BaF₂:Y, which are considered for Mu2e-II. Crystal radiation hardness against gamma-rays and hadrons is reported. Current status and development effort for the BaF₂:Y crystals are discussed.https://resolver.caltech.edu/CaltechAUTHORS:20220510-165800495Search for light Higgs bosons from supersymmetric cascade decays in pp collisions at √s = 13 TeV
https://authors.library.caltech.edu/records/1esma-pfg37
Year: 2023
DOI: 10.48550/arXiv.2204.13532
<p>A search is reported for pairs of light Higgs bosons (H₁) produced in supersymmetric cascade decays in final states with small missing transverse momentum. A data set of LHC pp collisions collected with the CMS detector at <strong>√</strong>s =<strong> </strong>13TeV and corresponding to an integrated luminosity of 138fb⁻¹ is used. The search targets events where both H₁ bosons decay into bb̅ pairs that are reconstructed as large-radius jets using substructure techniques. No evidence is found for an excess of events beyond the background expectations of the standard model (SM). Results from the search are interpreted in the next-to-minimal supersymmetric extension of the SM, where a "singlino" of small mass leads to squark and gluino cascade decays that can predominantly end in a highly Lorentz-boosted singlet-like H₁ and a singlino-like neutralino of small transverse momentum. Upper limits are set on the product of the squark or gluino pair production cross section and the square of the bb̅ branching fraction of the H₁ in a benchmark model containing almost mass-degenerate gluinos and light-flavour squarks. Under the assumption of an SM-like H₁) → bb̅ branching fraction, H₁ bosons with masses in the range 40–120 GeV arising from the decays of squarks or gluinos with a mass of 1200–2500 GeV are excluded at 95% confidence level.</p>https://authors.library.caltech.edu/records/1esma-pfg37Measurements of jet multiplicity and jet transverse momentum in multijet events in proton–proton collisions at √s = 13 TeV
https://authors.library.caltech.edu/records/wd64t-qq504
Year: 2023
DOI: 10.48550/arXiv.2210.13557
PMCID: PMC10444701
<p>Multijet events at large transverse momentum (pT) are measured at s√ = 13 TeV using data recorded with the CMS detector at the LHC, corresponding to an integrated luminosity of 36.3 fb−1. The multiplicity of jets with pT > 50 GeV that are produced in association with a high-pT dijet system is measured in various ranges of the pT of the jet with the highest transverse momentum and as a function of the azimuthal angle difference Δϕ1,2 between the two highest pT jets in the dijet system. The differential production cross sections are measured as a function of the transverse momenta of the four highest pT jets. The measurements are compared with leading and next-to-leading order matrix element calculations supplemented with simulations of parton shower, hadronization, and multiparton interactions. In addition, the measurements are compared with next-to-leading order matrix element calculations combined with transverse-momentum dependent parton densities and transverse-momentum dependent parton shower.</p>https://authors.library.caltech.edu/records/wd64t-qq504Observation of τ lepton pair production in ultraperipheral lead-lead collisions at √sNN=5.02TeV
https://authors.library.caltech.edu/records/n454t-1jc25
Year: 2023
DOI: 10.48550/arXiv.2206.05192
<p>We present an observation of photon-photon production of <span class="MathJax"><span class="math"><span class="mrow"><span class="mi">τ</span></span></span></span> lepton pairs in ultraperipheral lead-lead collisions. The measurement is based on a data sample with an integrated luminosity of 404 <span class="MathJax"><span class="math"><span class="mrow"><span class="mi">μ</span></span></span></span>b<span class="MathJax"><span class="math"><span class="mrow"><span class="msubsup"><span class="mi"></span><span class="texatom"><span class="mrow"><span class="mo">−</span><span class="mn">1</span></span></span></span></span></span></span> collected by the CMS experiment at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The <span class="MathJax"><span class="math"><span class="mrow"><span class="mi">γ</span><span class="mi">γ</span></span></span></span> <span class="MathJax"><span class="math"><span class="mrow"><span class="mo">→</span></span></span></span> <span class="MathJax"><span class="math"><span class="mrow"><span class="msubsup"><span class="mi">τ</span><span class="mo">+</span></span><span class="msubsup"><span class="mi">τ</span><span class="mo">−</span></span></span></span></span> process is observed for <span class="MathJax"><span class="math"><span class="mrow"><span class="mi">τ</span><span class="mi">τ</span></span></span></span> events with a muon and three charged hadrons in the final state. The measured fiducial cross section is <span class="MathJax"><span class="math"><span class="mrow"><span class="mi">σ</span><span class="mo">(</span><span class="mi">γ</span><span class="mi">γ</span></span></span></span> <span class="MathJax"><span class="math"><span class="mrow"><span class="mo">→</span></span></span></span> <span class="MathJax"><span class="math"><span class="mrow"><span class="msubsup"><span class="mi">τ</span><span class="mo">+</span></span><span class="msubsup"><span class="mi">τ</span><span class="mo">−</span></span><span class="mo">)</span></span></span></span> = 4.8 <span class="MathJax"><span class="math"><span class="mrow"><span class="mo">±</span></span></span></span> 0.6 (stat) <span class="MathJax"><span class="math"><span class="mrow"><span class="mo">±</span></span></span></span> 0.5 (syst) <span class="MathJax"><span class="math"><span class="mrow"><span class="mi">μ</span></span></span></span>b, in agreement with leading-order QED predictions. Using <span class="MathJax"><span class="math"><span class="mrow"><span class="mi">σ</span><span class="mo">(</span><span class="mi">γ</span><span class="mi">γ</span></span></span></span> <span class="MathJax"><span class="math"><span class="mrow"><span class="mo">→</span></span></span></span> <span class="MathJax"><span class="math"><span class="mrow"><span class="msubsup"><span class="mi">τ</span><span class="mo">+</span></span><span class="msubsup"><span class="mi">τ</span><span class="mo">−</span></span><span class="mo">)</span></span></span></span>, we estimate a model-dependent value of the anomalous magnetic moment of the <span class="MathJax"><span class="math"><span class="mrow"><span class="mi">τ</span></span></span></span> lepton of <span class="MathJax"><span class="math"><span class="mrow"><span class="msubsup"><span class="mi">a</span><span class="mi">τ</span></span></span></span></span> = 0.001 <span class="MathJax"><span class="math"><span class="mrow"><span class="msubsup"><span class="mi"></span><span class="texatom"><span class="mrow"><span class="mo">+</span><span class="mn">0.055</span></span></span><span class="texatom"><span class="mrow"><span class="mo">−</span><span class="mn">0.089</span></span></span></span></span></span></span>.</p>https://authors.library.caltech.edu/records/n454t-1jc25