NNLO contributions to inclusive-jet production in DIS and determination of \alpha_s

We present the first calculation of inclusive jet production in deep-inelastic scattering with approximate next-to-next-to-leading order (aNNLO) contributions, obtained from a unified threshold resummation formalism. The leading coefficients are computed analytically. We show that the aNNLO contributions reduce the theoretical prediction for jet production in deep-inelastic scattering, improve the description of the final HERA data in particular at high photon virtuality Q^2 and increase the central fit value of the strong coupling constant.Comment: 5 pages, 2 figures. arXiv admin note: text overlap with arXiv:1310.172

A 96 GeV Higgs boson in the N2HDM

We discuss a ∼3σ signal (local) in the light Higgs-boson search in the diphoton decay mode at ∼96GeV as reported by CMS, together with a ∼2σ excess (local) in the bb¯ final state at LEP in the same mass range. We interpret this possible signal as a Higgs boson in the 2 Higgs Doublet Model with an additional real Higgs singlet (N2HDM). We find that the lightest Higgs boson of the N2HDM can perfectly fit both excesses simultaneously, while the second lightest state is in full agreement with the Higgs-boson measurements at 125GeV, and the full Higgs-boson sector is in agreement with all Higgs exclusion bounds from LEP, the Tevatron and the LHC as well as other theoretical and experimental constraints. We show that only the N2HDM type II and IV can fit both the LEP excess and the CMS excess with a large ggF production component at ∼96GeV. We derive bounds on the N2HDM Higgs sector from a fit to both excesses and describe how this signal can be further analyzed at the LHC and at future e+e- colliders, such as the ILCThe work was supported in part by the MEINCOP (Spain) under contract FPA2016-78022-P and in part by the AEI through the grant IFT Centro de Excelencia Severo Ochoa SEV-2016-0597. The work of T.B. and S.H. was supported in part by the Spanish Agencia Estatal de Investigación (AEI), in part by the EU Fondo Europeo de Desarrollo Regional (FEDER) through the project FPA2016-78645-P, in part by the “Spanish Red Consolider MultiDark” FPA2017-90566-REDC. The work of T.B. was funded by Fundación La Caixa under ‘La Caixa-Severo Ochoa’ international predoctoral gran

Precise prediction for the Higgs-Boson Masses in the μν\mu\nuSSM

The $\mu\nu$SSM is a simple supersymmetric extension of the Standard Model (SM) capable of predicting neutrino physics in agreement with experiment. In this paper we perform the complete one-loop renormalization of the neutral scalar sector of the $\mu\nu$SSM with one generation of right-handed neutrinos in a mixed on-shell/$\overline{\mathrm{DR}}$ scheme. The renormalization procedure is discussed in detail, emphasizing conceptual differences to the minimal (MSSM) and next-to-minimal (NMSSM) supersymmetric standard model regarding the field renormalization and the treatment of non-flavor-diagonal soft mass parameters, which have their origin in the breaking of $R$-parity in the $\mu\nu$SSM. We calculate the full one-loop corrections to the neutral scalar masses of the $\mu\nu$SSM. The one-loop contributions are supplemented by available MSSM higher-order corrections. We obtain numerical results for a SM-like Higgs boson mass consistent with experimental bounds. We compare our results to predictions in the NMSSM to obtain a measure for the significance of genuine $\mu\nu$SSM-like contributions. We only find minor corrections due to the smallness of the neutrino Yukawa couplings, indicating that the Higgs boson mass calculations in the $\mu\nu$SSM are at the same level of accuracy as in the NMSSM. Finally we show that the $\mu\nu$SSM can accomodate a Higgs boson that could explain an excess of $\gamma\gamma$ events at $\sim 96\, \mathrm{GeV}$ as reported by CMS, as well as the $2\,\sigma$ excess of $b \bar{b}$ events observed at LEP at a similar mass scale.Comment: Version published in EPJC. Numerical analysis improved, numerical results for NMSSM comparison changed accordingly, overall conclusions unchanged. 56 pages, 12 figure

The 95.4 GeV di-photon excess at ATLAS and CMS

The ATLAS collaboration has recently reported the results of a low-mass Higgs-boson search in the di-photon final state based on the full Run 2 data set. The results are based on an improved analysis w.r.t. the previous analysis, which included a part of the Run 2 data, with a substantially better sensitivity. The ``model-dependent'' search carried out by ATLAS shows an excess of events at a mass of about 95.4 GeV with a local significance of $1.7\,\sigma$. The results are compatible with a previously reported excess at the same mass, but somewhat higher significance of $2.9\,\sigma$, from the CMS collaboration, also based on the full Run 2 data set. Combining the two results (neglecting possible correlations) we find a signal strength of $\mu_{\gamma\gamma}^{\rm ATLAS+CMS} = 0.27^{+0.10}_{-0.09}$, corresponding to an excess of $3.2\,\sigma$. In this work, we investigate the implications of this result, updating a previous analysis based solely on the CMS Run 2 data. We demonstrate that the ATLAS/CMS combined di-photon excess can be interpreted as the lightest Higgs boson in a Two-Higgs doublet model that is extended by a complex singlet (S2HDM) of Yukawa types II and IV, while being in agreement with all other experimental and theoretical constraints.Comment: v.1: 9 pages, 2 figures. arXiv admin note: substantial text overlap with arXiv:2303.1201

The "96 GeV excess" at the LHC

The CMS collaboration reported an intriguing \sim 3 sigma (local) excess at 96 GeV in the light Higgs-boson search in the diphoton decay mode. This mass coincides with a \sim 2 sigma (local) excess in the bb final state at LEP. We briefly review the proposed combined interpretations for the two excesses. In more detail we review the interpretation of this possible signal as the lightest Higgs boson in the 2 Higgs Doublet Model with an additional real Higgs singlet (N2HDM). We show which channels have the best prospects for the discovery of additional Higgs bosons at the upcoming Run 3 of the LHC.Comment: 7 pages, 1 figure. Talk presented at the IAS Program on High Energy Physics (HEP) 2020. These proceedings complement with new material the original paper, arXiv:1903.11661, and the subsequent arXiv:1910.06858, arXiv:2002.06904. On popular demand we have included again a list of models explaining the excesse

The Universal One-Loop Effective Action

We present the universal one-loop effective action for all operators of dimension up to six obtained by integrating out massive, non-degenerate multiplets. Our general expression may be applied to loops of heavy fermions or bosons, and has been checked against partial results available in the literature. The broad applicability of this approach simplifies one-loop matching from an ultraviolet model to a lower-energy effective field theory (EFT), a procedure which is now reduced to the evaluation of a combination of matrices in our universal expression, without any loop integrals to evaluate. We illustrate the relationship of our results to the Standard Model (SM) EFT, using as an example the supersymmetric stop and sbottom squark Lagrangian and extracting from our universal expression the Wilson coefficients of dimension-six operators composed of SM fields.Comment: 30 pages, v2 contains additional comments and corrects typos, version accepted for publication in JHE

Dimension-6 operator analysis of the CLIC sensitivity to new physics

We estimate the possible accuracies of measurements at the proposed CLICe+ e− collider of Higgs and W+W− production at centre-of-mass energies up to 3 TeV, incorporating also Higgsstrahlung projections at higher energies that had not been considered previously, and use them to explore the prospective CLIC sensitivities to decoupled new physics. We present the resulting constraints on the Wilson coefficients of dimension6 operators in a model-independent approach based on the Standard Model effective field theory (SM EFT). The higher centre-of-mass energy of CLIC, compared to other projects such as the ILC and CEPC, gives it greater sensitivity to the coefficients of some of the operators we study. We find that CLIC Higgs measurements may be sensitive to new physics scales Λ = O(10) TeV for individual operators, reduced to O(1) TeV sensitivity for a global fit marginalising over the coefficients of all contributing operators. We give some examples of the corresponding prospective constraints on specific scenarios for physics beyond the SM, including stop quarks and the dilaton/radion

Higgs-mass predictions in the MSSM and beyond

Predictions for the Higgs masses are a distinctive feature of supersymmetric extensions of the Standard Model, where they play a crucial role in constraining the parameter space. The discovery of a Higgs boson and the remarkably precise measurement of its mass at the LHC have spurred new efforts aimed at improving the accuracy of the theoretical predictions for the Higgs masses in supersymmetric models. The "Precision SUSY Higgs Mass Calculation Initiative" (KUTS) was launched in 2014 to provide a forum for discussions between the different groups involved in these efforts. This report aims to present a comprehensive overview of the current status of Higgs-mass calculations in supersymmetric models, to document the many advances that were achieved in recent years and were discussed during the KUTS meetings, and to outline the prospects for future improvements in these calculations