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ATLAS Collaboration(Aad, G. et al), Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Cardillo, F., Castillo, F. L., et al. (2021). Search for charged Higgs bosons decaying into a top quark and a bottom quark at root s=13 TeV with the ATLAS detector. J. High Energy Phys., 06(6), 145–47pp.
Abstract: A search for charged Higgs bosons decaying into a top quark and a bottom quark is presented. The data analysed correspond to 139 fb(-1) of proton-proton collisions at root s = 13TeV, recorded with the ATLAS detector at the LHC. The production of a heavy charged Higgs boson in association with a top quark and a bottom quark, pp -> tbH(+) -> tbtb, is explored in the H+ mass range from 200 to 2000 GeV using final states with jets and one electron or muon. Events are categorised according to the multiplicity of jets and b-tagged jets, and multivariate analysis techniques are used to discriminate between signal and background events. No significant excess above the background-only hypothesis is observed and exclusion limits are derived for the production cross-section times branching ratio of a charged Higgs boson as a function of its mass; they range from 3.6 pb at 200 GeV to 0.036 pb at 2000 GeV at 95% confidence level. The results are interpreted in the hMSSM and M-h(125) scenarios.
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Pich, A., & Rodriguez-Sanchez, A. (2022). Violations of quark-hadron duality in low-energy determinations of alpha(s). J. High Energy Phys., 07(7), 145–42pp.
Abstract: Using the spectral functions measured in tau decays, we investigate the actual numerical impact of duality violations on the extraction of the strong coupling. These effects are tiny in the standard alpha(s)(m(tau)(2)) determinations from integrated distributions of the hadronic spectrum with pinched weights, or from the total tau hadronic width. The pinched-weight factors suppress very efficiently the violations of duality, making their numerical effects negligible in comparison with the larger perturbative uncertainties. However, combined fits of alpha(s) and duality-violation parameters, performed with non-protected weights, are subject to large systematic errors associated with the assumed modelling of duality-violation effects. These uncertainties have not been taken into account in the published analyses, based on specific models of quark-hadron duality.
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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Aparisi Pozo, J. A., Bailey, A. J., Barranco Navarro, L., Cabrera Urban, S., et al. (2019). Searches for third-generation scalar leptoquarks in s=13 TeV pp collisions with the ATLAS detector. J. High Energy Phys., 06(6), 144–48pp.
Abstract: Limits are set on the pair production of scalar leptoquarks, where all possible decays of the leptoquark into a quark (t, b) and a lepton (, ) of the third generation are considered. The limits are presented as a function of the leptoquark mass and the branching ratio into charged leptons for up-type (LQ<sub ) and down-type (/t) leptoquarks. Many results are reinterpretations of previously published ATLAS searches. In all cases, LHC proton-proton collision data at a centre-of-mass energy of = 13 TeV recorded by the ATLAS detector in 2015 and 2016 are used, corresponding to an integrated luminosity of 36.1 fb(-1). Masses below 800 GeV are excluded for both LQu and LQd independently of the branching ratio, with masses below about 1 TeV being excluded for the limiting cases of branching ratios equal to zero or unity.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., et al. (2020). Measurement of the shape of the B-s(0) -> D-s*(-) mu(+) nu(mu) differential decay rate. J. High Energy Phys., 12(12), 144–32pp.
Abstract: The shape of the B-s(0) -> D-s*mu(+)nu(mu) differential decay rate is obtained as a function of the hadron recoil parameter using proton-proton collision data at a centreof-mass energy of 13TeV, corresponding to an integrated luminosity of 1.7 fb(-1) collected by the LHCb detector. The B-s(0) -> D-s*(-)mu(+)nu(mu) decay is reconstructed through the decays D-s*(-) up arrow D-s(-) gamma and D-s(-) -> K-K+pi(-). The differential decay rate is fitted with the CapriniLellouch-Neubert (CLN) and Boyd-Grinstein-Lebed (BGL) parametrisations of the form factors, and the relevant quantities for both are extracted.
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Akhmedov, E., & Martinez-Mirave, P. (2022). Solar (v(e))over-bar flux: revisiting bounds on neutrino magnetic moments and solar magnetic field. J. High Energy Phys., 10(10), 144–35pp.
Abstract: The interaction of neutrino transition magnetic dipole moments with magnetic fields can give rise to the phenomenon of neutrino spin-flavour precession (SFP). For Majorana neutrinos, the combined action of SFP of solar neutrinos and flavour oscillations would manifest itself as a small, yet potentially detectable, flux of electron antineutrinos coming from the Sun. Non-observation of such a flux constrains the product of the neutrino magnetic moment μand the strength of the solar magnetic field B. We derive a simple analytical expression for the expected (v(e)) over bar appearance probability in the three-flavour framework and we use it to revisit the existing experimental bounds on μB. A full numerical calculation has also been performed to check the validity of the analytical result. We also present our numerical results in energy-binned form, convenient for analyses of the data of the current and future experiments searching for the solar (v(e)) over bar flux. In addition, we give a comprehensive compilation of other existing limits on neutrino magnetic moments and of the expressions for the probed effective magnetic moments in terms of the fundamental neutrino magnetic moments and leptonic mixing parameters.
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