ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2025). Search for a heavy charged Higgs boson decaying into a W boson and a Higgs boson in final states with leptons and b-jets in √s=13 TeV pp collisions with the ATLAS detector. J. High Energy Phys., 02(2), 143–69pp.
Abstract: This article presents a search for a heavy charged Higgs boson produced in association with a top quark and a bottom quark, and decaying into a W boson and a 125 GeV Higgs boson h. The search is performed in final states with one charged lepton, missing transverse momentum, and jets using proton-proton collision data at root s = 13 TeV recorded with the ATLAS detector during Run 2 of the LHC at CERN. This data set corresponds to a total integrated luminosity of 140 fb(-1). The search is conducted by examining the reconstructed invariant mass distribution of the Wh candidates for evidence of a localised excess in the charged Higgs boson mass range from 250 GeV to 3 TeV. No significant excess of data over the expected background is observed and 95% confidence-level upper limits between 2.8 pb and 1.2 fb are placed on the production cross-section times branching ratio for charged Higgs bosons decaying into Wh.
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LHCb Collaboration(Aaij, R. et al), Fernandez Casani, A., Jaimes Elles, S. J., Jashal, B. K., Libralon, S., Martinez-Vidal, F., et al. (2025). Measurement of the multiplicity dependence of Γ production ratios in pp collisions at √s=13 Tev. J. High Energy Phys., 05(5), 011–24pp.
Abstract: The Gamma(2S) and Gamma(3S) production cross-sections are measured relative to that of the Gamma(1S) meson, as a function of charged-particle multiplicity in proton-proton collisions at a centre-of-mass energy of 13TeV. The measurement uses data collected by the LHCb experiment in 2018 corresponding to an integrated luminosity of 2 fb(-1). Both the Gamma(2S)to-Gamma(1S) and Gamma(3S)-to-Gamma(1S) cross-section ratios are found to decrease significantly as a function of event multiplicity, with the Gamma(3S)-to-Gamma(1S) ratio showing a steeper decline towards high multiplicity. This hierarchy is qualitatively consistent with the comover model predictions, indicating that final-state interactions play an important role in bottomonia production in high-multiplicity events.
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LHCb Collaboration(Aaij, R. et al), Fernandez Casani, A., Jaimes Elles, S. J., Jashal, B. K., Libralon, S., Martinez-Vidal, F., et al. (2025). Measurement of the CKM angle γ in B± → DK*(892)± decays. J. High Energy Phys., 02(2), 113–37pp.
Abstract: Measurements of CP observables and the CKM angle gamma are performed in B-+/- -> DK*(892)(+/-) decays, where D represents a superposition of D-0 and (D) over bar (0) states, using the LHCb dataset collected during Run 1 (2011-2012) and Run 2 (2015-2018). A study of this channel is presented with the D meson reconstructed in two-body final states K-+/- pi(+/-), K+ K- and pi(+)pi(-); four-body final states K-+/-pi(-/+) pi(+/-) pi(-/+) and pi(+) pi(-) pi(+)pi(-); and threebody final states K-S(0)pi(+) pi(-) and K-S(0) K+ K-. This analysis includes the first observation of the suppressed B +/-. [pi(+/-) K-+/-](D)K*(+/-) and B +/-. [pi(+/-) K--/+ pi(+/-)pi(-/+)](D)K*(+/-) decays. The combined result gives gamma = (63 +/- 13)degrees.
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ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2025). Search for the associated production of charm quarks and a Higgs boson decaying into a photon pair with the ATLAS detector. J. High Energy Phys., 02(2), 045–36pp.
Abstract: A search for the production of a Higgs boson and one or more charm quarks, in which the Higgs boson decays into a photon pair, is presented. This search uses proton-proton collision data with a centre-of-mass energy of root s = 13TeV and an integrated luminosity of 140 fb(-1) recorded by the ATLAS detector at the Large Hadron Collider. The analysis relies on the identification of charm-quark-containing jets, and adopts an approach based on Gaussian process regression to model the non-resonant di-photon background. The observed (expected, assuming the Standard Model signal) upper limit at the 95% confidence level on the cross-section for producing a Higgs boson and at least one charm-quark-containing jet that passes a fiducial selection is found to be 10.6 pb (8.8 pb). The observed (expected) measured cross-section for this process is 5.3 +/- 3.2 pb (2.9 +/- 3.1 pb).
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ATLAS Collaboration(Aad, G. et al), Aikot, A., Amos, K. R., Bouchhar, N., Cabrera Urban, S., Cantero, J., et al. (2025). Search for single-production of vector-like quarks decaying into Wb in the fully hadronic final state in pp collisions at √s=13 TeV with the ATLAS detector. J. High Energy Phys., 02(2), 075–44pp.
Abstract: A search for T and Y vector-like quarks produced in proton-proton collisions at a centre-of-mass energy of 13 TeV and decaying into Wb in the fully hadronic final state is presented. The search uses 139 fb(-1) of data collected by the ATLAS detector at the LHC from 2015 to 2018. The final state is characterised by a hadronically decaying W boson with large Lorentz boost and a b-tagged jet, which are used to reconstruct the invariant mass of the vector-like quark candidate. The main background is QCD multijet production, which is estimated using a data-driven method. Upon finding no significant excess in data, mass limits at 95% confidence level are obtained as a function of the global coupling parameter, kappa. The observed lower limits on the masses of Y quarks with kappa = 0.5 and kappa = 0.7 are 2.0 TeV and 2.4 TeV, respectively. For T quarks, the observed mass limits are 1.4 TeV for kappa = 0.5 and 1.9 TeV for kappa = 0.7.
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