Search

Abstract Vbfnlo is a flexible parton level Monte Carlo program for the simulation of vector boson fusion (VBF), QCD-induced single and double vector boson production plus two jets, and double and triple vector boson production (plus jet) in hadronic collisions at next-to-leading order (NLO) in the strong coupling constant, as well as Higgs boson plus two and three jet production via gluon fusion at the one-loop level. For the new version – Version 3.0 – several major enhancements have been included. An interface according to the Binoth Les Houches Accord (BLHA) has been added for all VBF and di/tri-boson processes including fully leptonic decays. For all dimension-8 operators affecting vector boson scattering (VBS) processes, a modified T-matrix unitarization procedure has been implemented. Several new production processes have been added, namely the VBS $$Z\gamma jj$$ Z γ j j and $$\gamma \gamma jj$$ γ γ j j processes at NLO, $$\gamma \gamma jj $$ γ γ j j , WWj and ZZj production at NLO including the loop-induced gluon-fusion contributions and the gluon-fusion one-loop induced $$\varPhi jjj$$ Φ j j j ( $$\varPhi $$ Φ is a CP-even or CP-odd scalar boson) process at LO, retaining the full top-mass dependence. Finally, the code has been parallelized using Openmpi.

Abstract We present new results of next-to-leading order (NLO) electroweak corrections to doubly-polarized cross sections of $$W^+W^-$$ W + W - production at the LHC. The calculation is performed for the leptonic final state of $$e^{+}\mu _{e} \mu ^{-} {\bar{\nu }}_{\mu }$$ e + μ e μ - ν ¯ μ using the double-pole approximation in the diboson center-of-mass frame. NLO QCD corrections and subleading contributions from the gg, $$b{\bar{b}}$$ b b ¯ , $$\gamma \gamma $$ γ γ induced processes are taken into account in the numerical results. We found that NLO EW corrections are small for angular distributions but can reach tens of percent for transverse momentum distributions at high energies, e.g. reaching $$-40\%$$ - 40 % at $$p_{T,e}\approx 300$$ p T , e ≈ 300 GeV. In these high $$p_T$$ p T regions, EW corrections are largest for the doubly-transverse mode.

Abstract We investigate possible effects of unparticles at the MUonE experiment by considering a general model for unparticle with broken scale invariance, characterized by the scaling dimension d and the energy scale $$\mu $$ μ at which the scale invariance is broken. Taking into account available relevant constraints on the couplings of the unparticles with the Standard Model (SM) leptons, we found that the MUonE experiment at the level of 10 ppm systematic accuracy is sensitive to such effects if $$1

Abstract The doubly-polarized production of $$W^\pm Z$$ W ± Z pairs at the Large Hadron Collider (LHC) is presented at next-to-leading order (NLO) accuracy both for the electroweak (EW) and QCD corrections, including a detailed description of the calculational method using the double-pole approximation. Numerical results at the 13 TeV LHC are presented in particular for the $$W^- Z$$ W - Z case in the $$e^-\bar{\nu }_e \mu ^+\mu ^-$$ e - ν ¯ e μ + μ - channel using ATLAS fiducial cuts and for polarized distributions defined in the WZ center-of-mass system. The NLO EW corrections relative to the NLO QCD predictions are found to be smaller than 5% in most kinematic distributions, but can reach the level of 10% in some distributions such as lepton transverse momentum distributions or rapidity separation between the electron and the Z boson. EW corrections are not uniform for different polarizations. A comparison between the new ATLAS measurement of polarization fractions to our theoretical prediction is presented.

Abstract We present new results for next-to-leading order (NLO) electroweak (EW) corrections to double polarization signals in the WZ production channel at the LHC using the $$e^+\nu _e \mu ^+ \mu ^-$$ e + ν e μ + μ - final state. It is found that the EW corrections are most sizable in the transverse momentum distributions of the doubly longitudinal polarization, being around $$-\,10$$ - 10 % compared to the NLO QCD prediction at $$p_{T,e}\approx 200$$ p T , e ≈ 200 GeV, which is in the accessible energy range of the current LHC data.

Abstract The new results on the muon anomalous magnetic moment (AMM) published by Fermilab in 2021 did not lead to a reduction of its long-pending deviation from the Standard Model (SM) value by more than 4 $$\sigma $$ σ . The explanation of this discrepancy by adding new particles to the theory puts many new physics models under tension when combined with the null results of the LHC direct searches for new particles. In this paper, we investigate the CP-violating Next-to-Minimal Supersymmetric extension of the SM (NMSSM) with and without an inverse seesaw mechanism. We compute the one-loop supersymmetric contributions to the AMM and the two-loop Barr–Zee-type diagrams with effective Higgs couplings to photons for the leptonic electric dipole moments (EDMs). The effects of the extended (s)neutrino sector on the muon AMM and on the mass of the SM-like Higgs boson can be significant. Complex phases can have an important impact on the AMM. On the other hand, the stringent limits from the EDMs on the complex phases have to be taken into account. Our calculations have been implemented in the Fortran codes NMSSMCALC and NMSSMCALC-nuSS which are publicly available. Besides the leptonic AMMs and EDMs, these programs can compute the Higgs boson masses and mixings, together with Higgs boson decay widths and branching ratios taking into account the most up-to-date higher-order corrections in the NMSSM with and without inverse seesaw mechanism.