6,853 research outputs found

    The production and decay of the top partner TT in the left-right twin higgs model at the ILC and CLIC

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    The left-right twin Higgs model (LRTHM) predicts the existence of the top partner TT. In this work, we make a systematic investigation for the single and pair production of this top partner TT through the processes: e^{+}e^{-}\to t\ov{T} + T\bar{t} and T\ov{T}, the neutral scalar (the SM-like Higgs boson hh or neutral pseudoscalar boson ϕ0\phi^{0}) associate productions e^{+}e^{-}\to t\ov{T}h +T\bar{t}h, T\ov{T}h, t\ov{T}\phi^{0}+T\bar{t}\phi^{0} and T\ov{T}\phi^{0}. From the numerical evaluations for the production cross sections and relevant phenomenological analysis we find that (a) the production rates of these processes, in the reasonable parameter space, can reach the level of several or tens of fb; (b) for some cases, the peak value of the resonance production cross section can be enhanced significantly and reaches to the level of pb; (c) the subsequent decay of T→ϕ+b→tbˉbT\to \phi^{+}b \to t\bar{b}b may generate typical phenomenological features rather different from the signals from other new physics models beyond the standard model(SM); and (d) since the relevant SM background is generally not large, some signals of the top partner TT predicted by the LRTHM may be detectable in the future ILC and CLIC experiments.Comment: 20pages, 15 figures and 6 Tables. Minor corrections on text. new references adde

    Reservoir automatic history matching: Methods, challenges, and future directions

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    Reservoir history matching refers to the process of continuously adjusting the parameters of the reservoir model, so that its dynamic response will match the historical observation data, which is a prerequisite for making forecasts based on the reservoir model. With the development of optimization theory and machine learning algorithms, automatic history matching has made numerous breakthroughs for practical applications. In this perspective, the existing automatic history matching methods are summarized and divided into model-driven and surrogate-driven history matching methods according to whether the reservoir simulator needs to be run during the automatic history matching process. Then, the basic principles of these methods and their limitations in practical applications are outlined. Finally, the future trends of reservoir automatic history matching are discussed.Cited as: Liu, P., Zhang, K., Yao, J. Reservoir automatic history matching: Methods, challenges, and future directions. Advances in Geo-Energy Research, 2023, 7(2): 136-140. https://doi.org/10.46690/ager.2023.02.0

    Exploring the total Galactic extinction with SDSS BHB stars

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    Aims: We used 12,530 photometrically-selected blue horizontal branch (BHB) stars from the Sloan Digital Sky Survey (SDSS) to estimate the total extinction of the Milky Way at the high Galactic latitudes, RVR_V and AVA_V in each line of sight. Methods: A Bayesian method was developed to estimate the reddening values in the given lines of sight. Based on the most likely values of reddening in multiple colors, we were able to derive the values of RVR_V and AVA_V. Results: We selected 94 zero-reddened BHB stars from seven globular clusters as the template. The reddening in the four SDSS colors for the northern Galactic cap were estimated by comparing the field BHB stars with the template stars. The accuracy of this estimation is around 0.01\,mag for most lines of sight. We also obtained to be around 2.40±1.05\pm1.05 and AVA_V map within an uncertainty of 0.1\,mag. The results, including reddening values in the four SDSS colors, AVA_V, and RVR_V in each line of sight, are released on line. In this work, we employ an up-to-date parallel technique on GPU card to overcome time-consuming computations. We plan to release online the C++ CUDA code used for this analysis. Conclusions: The extinction map derived from BHB stars is highly consistent with that from Schlegel, Finkbeiner & Davis(1998). The derived RVR_V is around 2.40±1.05\pm1.05. The contamination probably makes the RVR_V be larger.Comment: 16 pages, 13 figures, 4 tables, accepted for publication in A&
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