The null results in dark matter direct detection experiments imply the present scalar dark matter (DM) annihilation cross section to bottom quark pairs through the Higgs boson exchange is smaller than about $10^{-31}$ cm$^3/$s for a wide DM mass range, which is much smaller than the required annihilation cross section for thermal relic DM. We propose models of a thermal relic DM with the present annihilation cross section being very suppressed. This property can be realized in an extra $U(1)$ gauge interacting complex scalar DM, where the thermal DM abundance is determined by coannihilation through the gauge interaction while the present annihilation is governed by Higgs bosons exchange processes. An interaction between DM and the extra $U(1)$ breaking Higgs field generates a small mass splitting between DM and its coannihilating partner so that coannihilation becomes possible and also the $Z'$-mediated scattering off with a nucleon in direct DM search becomes inelastic. We consider scalar dark matter in $U(1)_{B-L}, U(1)_{(B-L)_3}$ and $U(1)_{L_μ-L_τ}$ extended models and identify viable parameter regions. We also discuss various implications to future DM detection experiments, the DM interpretation of the gamma-ray excess in the globular cluster 47 Tucanae, the muon anomalous magnetic moment, the Hubble tension and others.
We calculate the fully differential Next-to-Leading Order (NLO) corrections to (longitudinally) polarized dijet production in deep inelastic scattering, featuring both neutral current and charged current processes. We also analyze their phenomenological impact in the Electron-Ion Collider (EIC) kinematics.
Main aim of this research consists in the description of Deep Inelastic Scattering (DIS) processes mediated by Charged Currents (CC), producing a massive quark in the final state. Formalism of DIS processes has been investigated in depth, including mass contributions for charged lepton. Semi-exclusive partonic coefficient functions for heavy quark production up to Next-to-Leading Order have been carried out in the context of perturbative QCD.
The production of jets in charged-current deep-inelastic scattering (CC DIS) probes simultaneously the strong and the electroweak sectors of the Standard Model; its measurement provides important information on the quark flavour structure of the proton. We compute third-order (N3LO) perturbative QCD corrections to this process, fully differential in the jet and lepton kinematics. We observe a substantial reduction in the theory uncertainty, to sub-percent level throughout the relevant kinematical range, thus enabling precision phenomenology with jet observables.
We perform the calculation of the fully differential single-jet production in longitudinally polarized deep inelastic scattering (DIS) at the next-to-next-to-leading order (NNLO) accuracy, featuring both neutral current and charged current processes. The computation is done with the projection-to-Born method (P2B), using the next-to-leading order (NLO) dijet calculation and the NNLO DIS structure functions as its main ingredients. We also analyze its phenomenological consequences in the kinematics of the future Electron-Ion Collider (EIC).
Charged current deep-inelastic scattering at three loops
本文导出了nu P - nubar P组合中中微子-质子深度非弹性散射的带电电流结构函数F_2、F_L和F_3对三个圈的微扰QCD修正。在首扭近似下，我们计算了F_2和F_L的前五个奇整数Mellin矩和F_3的前五个偶整数Mellin矩。作为一个新的结果，我们得到了O（α_s^3）的系数函数，而相应的反常维数与文献中的已知结果一致。
We present details on calculation of next-to-next-to-leading order QCD corrections to massive charged-current coefficient functions in deep-inelastic scattering. Especially we focus on the application to charm-quark production in neutrino scattering on fixed target that can be measured via the dimuon final state. We construct a fast interface to the calculation so for any parton distributions the cross sections can be evaluated within milliseconds by using the pre-generated interpolation grids. We discuss agreements of various theoretical predicitons with the NuTeV and CCFR dimuon data and the…
We present a systematic calculation of the charged current semi-inclusive deeply inelastic scattering process at leading order twist-3 level in the parton model. We consider the general form of the negatively charged beam scattering off the polarized target which has spin-1. The calculations are carried out by applying the collinear expansion where multiple gluon scattering is taken into account and gauge links are obtained automatically. We first present the general form of the differential cross section in terms of the structure functions by kinematic analysis and then present the structure …
The production of jets in charged current deep inelastic scattering (CC DIS) constitutes a class of observables that can be used to simultaneously test perturbative predictions for the strong and the electroweak sectors of the Standard Model. We compute both single jet and di-jet production in CC DIS for the first time at next-to-next-to-leading order (NNLO) in the strong coupling. Our computation is fully differential in the jet and lepton kinematics, and we observe a substantial reduction of scale variation uncertainties in the NNLO predictions compared to next-to-leading order (NLO). Our ca…
We study charged lepton flavor violation (CLFV) associated with heavy quark pair production in lepton-nucleon deep-inelastic scattering $\ell_i N \to \ell_j q\bar{q} X$. Here $\ell_i$ and $\ell_j$ denote the initial and final leptons; $N$ and $X$ are respectively the initial nucleon and arbitrary final hadronic system. We employ a model Lagrangian in which a scalar and pseudoscalar mediator generates the CLFV. We derive heavy quark structure functions for scalar and pseudoscalar currents and compute momentum distributions of the final lepton for the process. Our focus is on the heavy quark mas…
In this paper, we study charged current deep inelastic scattering of muon neutrinos off ^{56}Fe nuclei using Hirai, Kumano and Saito model. The LHA Parton Distribution Functions (PDFs) - CT10 are used to describe the partonic content of hadrons. Modification of PDFs inside the nuclei is done using EPPS16 parameterization at next-to-leading order. Target mass correction has also been incorporated in the calculations. We calculate the structure functions (F_{2}(x,Q^{2}) and xF_{3}(x,Q^{2})), the ratios (R_{2}(x,Q^{2}) = \frac{F^{^{56}Fe}_{2}}{F^{Nucleon}_{2}} and R_{3}(x,Q^{2}) = \frac{F^{^{56}F…
Heavy-quark initiated charged-current deep-inelastic scattering coefficient functions through $\mathcal{O}(α_s^2)$
School of Physics, Shandong University（山东大学物理学院）；Tif Lab, Dipartimento di Fisica, Universit‘a di Milano and INFN, Sezione di Milano（米兰大学物理系蒂夫实验室及意大利国家核物理研究所米兰分部）
We study the proposal by Kharzeev-Levin to determine entanglement entropy in Deep Inelastic Scattering (DIS) from parton distribution functions (PDFs) and to relate the former to the entropy of final state hadrons. We find several uncertainties in the current comparison to data, in particular the overall normalization, the relation between charged versus total hadron multiplicity in the comparison to experimental results as well as different methods to determine the number of partons in Deep Inelastic Scattering. We further provide a comparison to data based on leading order HERA PDF as well a…
Effects of charged Higgs bosons in the deep inelastic process ν_τ {\cal N} \to τ^- X and the possibility of detecting tau-neutrinos at cosmic neutrino detectors
