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ATLAS Collaboration(Aad, G. et al), Amos, K. R., Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Cardillo, F., et al. (2022). Search for single production of a vectorlike T quark decaying into a Higgs boson and top quark with fully hadronic final states using the ATLAS detector. Phys. Rev. D, 105(9), 092012–34pp.
Abstract: A search is made for a vectorlike T quark decaying into a Higgs boson and a top quark in 13 TeV protonproton collisions using the ATLAS detector at the Large Hadron Collider with a data sample corresponding to an integrated luminosity of 139 fb???1. The Higgs-boson and top-quark candidates are identified in the all-hadronic decay mode, where H – bb ?? and t – bW – bqq??0 are reconstructed as large-radius jets. The candidate Higgs boson, top quark, and associated B hadrons are identified using tagging algorithms. No significant excess is observed above the background, so limits are set on the production cross section of a singlet T quark at 95% confidence level, depending on the mass mT and coupling ??T of the vectorlike T quark to Standard Model particles. In the considered mass range between 1.0 and 2.3 TeV, the upper limit on the allowed coupling values increases with mT from a minimum value of 0.35 for 1.07 < mT < 1.4 TeV to 1.6 for mT 1/4 2.3 TeV.
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LHCb Collaboration(Aaij, R. et al), Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., Ruiz Vidal, J., et al. (2022). Measurement of the charm mixing parameter y(CP)-y(CP)(K pi) using two-body D-0 meson decays. Phys. Rev. D, 105(9), 092013–17pp.
Abstract: A measurement of the ratios of the effective decay widths of D-0 -> pi(-)pi(+) and D-0 -> K- K+ decays over that of D-0 -> K-pi(+) decays is performed with the LHCb experiment using proton-proton collisions at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb(-1). These observables give access to the charm mixing parameters y(CP)(pi pi) – y(CP)(K pi )and y(CP)(KK) -y(CP)(K pi), and are measured as y(CP)(pi pi) – y(CP)(K pi) = (6.57 +/- 0.53 +/- 0.16) x 10(-3), y(CP)(KK) – y(CP)(K pi) = (7.08 +/- 0.30 +/- 0.14) x 10(-3), where the first uncertainties are statistical and the second systematic. The combination of the two measurements is Y-CP – y(CP)(K pi) = (6.96 +/- 0.26 +/- 0.13) x 10(-3), which is four times more precise than the previous world average.
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Majumdar, A., Papoulias, D. K., Srivastava, R., & Valle, J. W. F. (2022). Physics implications of recent Dresden-II reactor data. Phys. Rev. D, 106(9), 093010–14pp.
Abstract: Prompted by the recent Dresden-II reactor data, we examine its implications for the determination of the weak mixing angle, paying attention to the effect of the quenching function. We also determine the resulting constraints on the unitarity of the neutrino mixing matrix, as well as on the most general type of nonstandard neutral-current neutrino interactions.
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Ji, T., Dong, X. K., Albaladejo, M., Du, M. L., Guo, F. K., & Nieves, J. (2022). Establishing the heavy quark spin and light flavor molecular multiplets of the X(3872), Z(c)(3900), and X(3960) br. Phys. Rev. D, 106(9), 094002–13pp.
Abstract: Recently, the LHCb Collaboration reported a near-threshold enhancement X(3960) in the D+sD-s invariant mass distribution. We show that the data can be well described by either a bound or a virtual state below the D+sD-s threshold. The mass given by the pole position is (3928 +/- 3) MeV. Using this mass and the existing information on the X(3872) and Zc(3900) resonances, a complete spectrum of the S-wave hadronic molecules formed by a pair of ground state charmed and anticharmed mesons is established. Thus, pole positions of the partners of the X(3872) , Zc(3900) , and the newly observed D+sD-s state are predicted. Calculations have been carried out at the leading order of nonrelativistic effective field theory and considering both heavy quark spin and light flavor SU(3) symmetries, though conservative errors from the breaking of these symmetries are provided.
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Winney, D., Pilloni, A., Mathieu, V., Hiller Blin, A. N., Albaladejo, M., Smith, W. A., et al. (2022). XYZ spectroscopy at electron-hadron facilities. II. Semi-inclusive processes with pion exchange. Phys. Rev. D, 106(9), 094009–13pp.
Abstract: Semi-inclusive processes arc very promising to investigate XYZ hadrons at the next generation of electron-hadron facilities, because they generally boast higher cross sections. We extend our formalism of exclusive photoproduction to semi-inclusive final states. The inclusive production cross sections for charged axial-vector Z states from pion exchange are predicted. We isolate the contribution of Delta resonances at small missing mass. Production near threshold is shown to be enhanced roughly by a factor of two compared to the exclusive reaction. We benchmark the model with data of semi-inclusive b(1)(+/-) production.
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