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A toolkit of the stop search via the chargino decay

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Abstract

The top squark (stop) may dominantly decay to a bottom quark and a chargino if the mass difference between the stop and the lightest neutralino is comparable or less than the top quark mass. Such a moderately compressed spectrum is a challenging scenario for the stop search at the Large Hadron Collider, because it is difficult to separate the signals from the top and anti-top background. In this paper we focus on the di-leptonic decay channel, and consider many kinematic variables as possible discriminators. These include several M T2 variables and new “compatible-masses” variables which fully utilize all kinematic information of the background. We use several sample spectra with different characteristics to study the efficiencies of these variables in distinguishing the signal from the background. The finding is that different combinations of variables or strategies should be used for different spectra to maximally enhance the signal significance and expand the reach of the stop search in this scenario. The new variables that we proposed in this paper are also useful for other new physics searches with di-leptonic top and anti-top events as the dominant background.

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Authors and Affiliations

  1. Department of Physics, University of Wisconsin, Madison, WI, 53706, U.S.A.

    Yang Bai

  2. Department of Physics, University of California, Davis, CA, 95616, U.S.A.

    Hsin-Chia Cheng, Jason Gallicchio & Jiayin Gu

  3. South Pole Station, PSC 468, Box 400, APO AP, 96598, Antarctica

    Jason Gallicchio

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  1. Yang Bai
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  2. Hsin-Chia Cheng
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  3. Jason Gallicchio
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  4. Jiayin Gu
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Correspondence to Jiayin Gu.

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ArXiv ePrint: 1304.3148

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Bai, Y., Cheng, HC., Gallicchio, J. et al. A toolkit of the stop search via the chargino decay. J. High Energ. Phys. 2013, 85 (2013). https://doi.org/10.1007/JHEP08(2013)085

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  • DOI: https://doi.org/10.1007/JHEP08(2013)085

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