14 research outputs found

    First results from the HAYSTAC axion search

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    The axion is a well-motivated cold dark matter (CDM) candidate first postulated to explain the absence of CPCP violation in the strong interactions. CDM axions may be detected via their resonant conversion into photons in a "haloscope" detector: a tunable high-QQ microwave cavity maintained at cryogenic temperature, immersed a strong magnetic field, and coupled to a low-noise receiver. This dissertation reports on the design, commissioning, and first operation of the Haloscope at Yale Sensitive to Axion CDM (HAYSTAC), a new detector designed to search for CDM axions with masses above 2020 μeV\mu\mathrm{eV}. I also describe the analysis procedure developed to derive limits on axion CDM from the first HAYSTAC data run, which excluded axion models with two-photon coupling gaγγ≳2×10−14g_{a\gamma\gamma} \gtrsim 2\times10^{-14} GeV−1\mathrm{GeV}^{-1}, a factor of 2.3 above the benchmark KSVZ model, over the mass range 23.55<ma<24.023.55 < m_a < 24.0 μeV\mu\mathrm{eV}. This result represents two important achievements. First, it demonstrates cosmologically relevant sensitivity an order of magnitude higher in mass than any existing direct limits. Second, by incorporating a dilution refrigerator and Josephson parametric amplifier, HAYSTAC has demonstrated total noise approaching the standard quantum limit for the first time in a haloscope axion search.Comment: Ph.D. thesis. 346 pages, 58 figures. A few typos corrected relative to the version submitted to ProQues

    Endoscopic Cryotherapy of Lung and Bronchial Tumors: A Systematic Review

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    Background/Aims: We made a systematic review and evaluation of endoscopic cryotherapy of endobronchial tumors, investigating safety and efficacy. Methods: Qualified studies regarding endoscopic cryotherapy of lung tumors were systemically evaluated using available databases according to predefined criteria. Results: In total, 16 publications were included in the final assessment. A narrative synthesis was performed because a formal meta-analysis was not viable due to the lack of controlled studies and study heterogeneity. Overall success rates for significant recanalization of the obstruction were approximately 80%, although they varied, depending on disease status in the patient population. Complications from the procedure developed in 0-11.1% of cases, most of which were minor and controlled by conservative management. Although limited data were available on comprehensive functional assessment, some studies showed that respiratory symptoms, pulmonary function tests, and performance status were significantly improved. Conclusions: Endoscopic cryotherapy was found to be a safe and useful procedure in the management of endobronchial tumors although its efficacy and appropriate indications have yet to be determined in well-designed controlled studies
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