Chala, M. (2017). Direct bounds on heavy toplike quarks with standard and exotic decays. Phys. Rev. D, 96(1), 015028–14pp.
Abstract: Heavy vectorlike quarks with electric charge Q = 2/3 (also called heavy tops) appear naturally in many extensions of the Standard Model. Although these typically predict the existence of further particles below the TeV scale, direct searches for heavy tops have been performed assuming that they decay only into SM particles. The aim of this paper is to overcome this situation. We consider the most constraining experimental LHC searches for vectorlike quarks, including analyses of the 36 fb(-1) of data collected in the latest run at 13 TeV of center of mass energy, as well as searches sensitive to heavy tops decaying into a new scalar, S. Combining all these, we derive bounds for arbitrary values of the heavy top branching ratios. A simple code that automatizes this process is also provided. At the physics level, we demonstrate that bounds on heavy tops are not inevitably weaker in the presence of new light scalars. We find that heavy tops with masses below similar to 900 GeV are excluded by direct searches, independently of whether they decay into Zt, Ht, Wb or St (with S giving either missing energy of bottom quarks) or into any combination of them.
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Debastiani, V. R., Dias, J. M., & Oset, E. (2017). Study of the DKK and DK(K)over-bar systems. Phys. Rev. D, 96(1), 016014–9pp.
Abstract: Using the fixed center approximation to Faddeev equations, we investigate the DKK and DK (K) over bar three-body systems, considering that the DK dynamically generates, through its I = 0 component, the D(so)(*()2317) molecule. According to our findings, for the DK (K) over bar interaction we find evidence of a state I(J(p)) = 1/2 (0(-)) just above the D-s0(*)(2317) (K) over bar threshold and around the Df(0)(980) threshold, with mass of about 2833-2858 MeV, made mostly of Df(0)(980). On the other hand, no evidence related to a state from the DKK interaction is found. The state found could be seen in the ppD invariant mass.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2017). Observation of the B+ -> D*K-(+) pi(+) decay. Phys. Rev. D, 96(1), 011101–10pp.
Abstract: The B+ -> D*K--(+)pi(+) decay potentially provides an excellent way to investigate charm meson spectroscopy. The decay is searched for in a sample of proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, corresponding to an integrated luminosity of 3 fb(-1). A clear signal is observed, and the ratio of its branching fraction to that of the B+ -> D*(-)pi(+)pi(+) normalization channel is measured to be beta(B+ -> D*K--(+)pi(+))/beta(B+ -> D*(-)pi(+)pi(+)) = (6.39 +/- 0.27 +/- 0.48) x 10(-2); where the first uncertainty is statistical and the second is systematic. This is the first observation of the B+ -> D*K--(+)pi(+) decay.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2017). Measurements of electroweak W j j production and constraints on anomalous gauge couplings with the ATLAS detector. Eur. Phys. J. C, 77(7), 474–74pp.
Abstract: Measurements of the electroweak production of a W boson in association with two jets at high dijet invariant mass are performed using root s = 7 and 8 TeV proton-proton collision data produced by the Large Hadron Collider, corresponding respectively to 4.7 and 20.2 fb(-1) of integrated luminosity collected by the ATLAS detector. The measurements are sensitive to the production of a W boson via a triple-gauge-boson vertex and include both the fiducial and differential cross sections of the electroweak process.
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Abramowicz, H. et al, Boronat, M., Fuster, J., Garcia, I., Ros, E., & Vos, M. (2017). Higgs physics at the CLIC electron-positron linear collider. Eur. Phys. J. C, 77(7), 475–41pp.
Abstract: The Compact Linear Collider (CLIC) is an option for a future e(+) e(-) collider operating at centre-of-mass energies up to 3 TeV, providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC operating at three energy stages: root s = 350 GeV, 1.4 and 3 TeV. The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung (e(+) e(-) -> ZH) and WW-fusion (e(+) e(-) -> H nu(e) (nu) over bar (e)), resulting in precise measurements of the production cross sections, the Higgs total decay width Gamma(H), and model-independent determinations of the Higgs couplings. Operation at root s > 1 TeV provides high-statistics samples of Higgs bosons produced through WW-fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes e(+) e(-) -> t (t) over barH and e(+) e(-) -> HH nu(e) (nu) over bar (e) allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of the precision achievable with Higgs measurements at CLIC and describes the interpretation of these measurements in a global fit.
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