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ATLAS Collaboration(Aad, G. et al), Ahuja, S., Aikot, A., Cabrera Urban, S., Cantero, J., Carrion Martinez, C., et al. (2026). Calibration of the jet energy scale and resolution of small-radius jets using semileptonic t(t)over-bar events with the ATLAS detector. Eur. Phys. J. C, 86(8), 943–36pp.
Abstract: A measurement of correction factors for the hadronic jet energy scale and resolution in the ATLAS detector is presented. These correction factors account for differences between simulated and observed data. They are obtained by analysing a selection of top quark events collected in proton-proton collisions by ATLAS between the years 2015 and 2018 at a centre-of-mass energy root s = 13 TeV as well as in 2022 and 2023 at root s = 13.6 TeV. The impact of different jet energy scale or resolution corrections on the reconstructed mass of the hadronically decaying W boson from top-quark decays in simulation is quantified. The correction factors are extracted from a fit to the parameterised reconstructedW-boson mass distribution to data. The energy scale and resolution corrections are measured as a function of the jet transverse momentum between 20 and 200 GeV and absolute pseudorapidity less than 0.8. The uncertainties in the energy scale range from about 0.93% to about 1.7% for jets between 35 and 200 GeV, while for the energy resolution the uncertainties range from about 14 to 28%. The method presented will be used in conjunction with other techniques to further improve ATLAS jet energy scale and resolution precision.
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Cheng, H. Y., Guo, Z. H., He, X. G., Hou, Y. R., Kang, X. W., Kupsc, A., et al. (2027). CP violation studies at Super Tau-Charm Facility. Phys. Rep., 1210, 1–60.
Abstract: Charge-parity (CP) violation in the tau-charm energy region is a promising area for sensitive tests of Standard Model (SM) predictions and searches for new, beyond the SM physics. A future Tau-Charm Facility that operates at center-of-mass energies between 2.0 and 7.0 GeV, with a peak luminosity of 0.5 & times; 1035 cm-2 s-1, would provide huge numbers of hadrons and tau (tau) leptons that are produced in low-background environments and with well understood kinematic properties. In this report, prospects for unique studies of CP violation in the decay of charmed hadrons, and in the production and decay of hyperons and tau leptons at a next-generation tau-charm facility are discussed. In addition, opportunities for improved tests of CPT invariance test in K0-K & strns;0 mixing are presented. (c) 2026 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
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LHCb Collaboration(Aaij, R. et al), Fernandez Casani, A., Jaimes Elles, S. J., Libralon, S., Lucio Martinez, M., Martinez-Vidal, F., et al. (2026). CP Violation Analysis of Local and Nonlocal Amplitudes in the (B)over-bar0 → (K)over-bar*0μ+μ- Decay. Phys. Rev. Lett., 137(6), 061801–12pp.
Abstract: A search for CP violation in the (B) over bar (0) -> (K) over bar*(0)mu(+)mu(-) decay is performed using proton-proton collision data collected by the LHCb experiment during Run 1 and Run 2, corresponding to an integrated luminosity of 8.4 fb(-1). The analysis exploits the full angular distribution of the decay, providing sensitivity to CP-violating effects in both vector and axial-vector contributions to this flavor-changing neutral-current process. The complex Wilson coefficients are determined within the weak effective theory through an unbinned maximum-likelihood fit to the angular observables, incorporating nonlocal hadronic amplitudes across the full dimuon mass spectrum. The precision of the CP-violation observables is improved by an order of magnitude relative to previous measurements, with the imaginary parts of the Wilson coefficients now determined more precisely than the real parts. No significant CP violation is observed, and the results are consistent with the standard model.
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LHCb Collaboration(Aaij, R. et al), Fernandez Casani, A., Jaimes Elles, S. J., Jashal, B. K., Libralon, S., Lucio Martinez, M., et al. (2026). Evidence for the Rare Decay B+ → (Λ)over-barpμ+ μ-. Phys. Rev. Lett., 137(5), 051801–13pp.
Abstract: A search for the rare decay B+ -> (Lambda) over barp mu(+) mu(-) is performed using proton-proton collision data recorded by the LHCb experiment at a center-of-mass energy of root s = 13 TeV, corresponding to an integrated luminosity of 5.4 fb(-1). An excess of events is found with respect to the background-only expectation, with a signal significance of 3.5 standard deviations, in the low invariant-mass region of m((Lambda) over barp) < 2.8 GeV/c(2). The branching fraction is measured to be B-low(B+ -> <(Lambda)over bar>p mu(+) mu(-)) = (1.70(-0.56)(+0.65)(stat) +/- 0.17(syst)+/- 0.14(ext)) x 10(-8), where the last uncertainty is due to external inputs on B(B+ -> J/psi(Lambda) over barp) x B(J/psi -> mu(+) mu(-)). With no significant signal observed in the high m((Lambda) over barp) region above 2.8 GeV/c(2), an upper limit is set to be B-high(B+ -> (Lambda) over barp mu(+) mu(-)) < 2.8(3.7) x 10(-9) at the 90% (95%) confidence level.
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Wang, D. (2026). Possible evidences for cosmological massive neutrinos. Eur. Phys. J. Plus, 141(9), 1068–7pp.
Abstract: A key question in cosmology is whether massive neutrinos exist on cosmic scales. Current cosmological observations have severely compressed the viable range for neutrino masses and even prefer phenomenologically an effective negative mass. This poses a great challenge to the cosmological search for neutrinos. Based on current background and large scale structure data, taking a full red-shift and/or scale tomography method, we obtain one beyond 5 sigma , two 3 sigma , and two 2 sigma evidences of massive neutrinos, spanning both high and low red-shifts, as well as both small and intermediate scales. Specifically, for the case of red-shift tomography, we find the neutrino mass sum Sigma m nu 1=1.01-0.58+0.47 eV in z is an element of[0,1] using the data combination of CMB, BAO, and supernova, indicating a 2 sigma clue of nonzero neutrino mass, while the addition of WiggleZ galaxy power spectrum leads to Sigma m nu 1=0.65 +/- 0.25 eV, implying a 3 sigma evidence of massive neutrinos. For the case of scale tomography, we give Sigma m nu k1=0.75-0.27+0.20 eV in k is an element of[10-1,+infinity) h Mpc -1 using the combination of CMB and WiggleZ observations, revealing a beyond 5 sigma evidence of massive neutrinos at small scales, while combining CMB with DESY1 galaxy clustering, cosmic shear and galaxy-galaxy lensing data provides Sigma m nu k2=0.55 +/- 0.27 eV in k is an element of[10-2,10-1] h Mpc -1 , giving a 2 sigma hint at intermediate scales. For the case of red-shift and scale tomography, we obtain Sigma m nu 52=0.63-0.24+0.20 eV when z is an element of[100,1100] and k is an element of[10-2,10-1] h Mpc -1 , suggesting a similar to 3 sigma evidence of massive neutrinos. Interestingly, these five signals of nonzero neutrino masses are well consistent within 1 sigma confidence level, indicating a possible suppression of neutrino mass during the evolution of the universe. Using cosmic microwave background observations to constrain a red-shift and scale dependent neutrino mass, we make the first neutrino mass map through the cosmic history and full scales for future high-precision search. Our results could help understand the role massive neutrinos played in the evolution of the universe.
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