We explore the physics expected sensitivity at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he) to search for the anomalous quartic $WWγγ$ couplings in single $W$-boson production in association with a photon. We study the process $ep \to e^-γ^* p \to eWγq'X$ via the subprocess $γ^* q \to Wγq'$. The center-of-mass energies and luminosities of the LHeC are assumed to be $\sqrt{s}=1.30, 1.98$ TeV, ${\cal L}=10-100$ ${\rm fb^{-1} }$ and for the FCC-he $\sqrt{s}=3.46, 5.29$ TeV and ${\cal L}=100-1000$ ${\rm fb^{-1} }$. With these energies and luminosities, we estimate bounds on the anomalous quartic $WWγγ$ couplings at $95\%$ C.L., which can be an order of magnitude stringent than the experimental limits report by ATLAS and CMS Collaborations at the LHC.
The deep inelastic scattering mode of $t\overline{t}$ pair production at the proposed LHeC and FCC-eh is considered. We present a method to extract the top reduced cross section related to the transversal structure function $F_{2}(x,Q^{2})$ parameterization. Numerical calculations with known kinematics of the LHeC and FCC-eh colliders are demonstrated. The results obtained for charm and beauty pair production are comparable with the experimental data. We show that for a wide range of the momentum transfer into the top quark pair, the reduced cross section is well described by center-of-mass en…
We conducted a study on measuring $W^+W^-$ production and on the sensitivity limits at $95\%$ Confidence Level on thirteen anomalous couplings obtained by dimension-8 operators which are related to the anomalous quartic $WWγγ$ couplings. We consider the main $e^-p \to e^-γ^*γ^*p \to e^-W^+W^-p$ reaction with the sub-process $γ^*γ^* \to W^+W^-$ at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he). For the LHeC, energies of the $e^-$ beams are taken to be $E_e =60$ and 140 GeV and the energy of the $p$ beams is taken to be $E_p = 7$ TeV. For the …
Extensions of the Standard Model (SM) gauge group with a new $U(1)_X$ predict an additional gauge boson. Through kinetic mixing with the SM photons featured by a coupling $ε$, the ensuing so-called dark photons $γ'$, which acquire mass as a result of the breaking of the gauge group $U(1)_X$, can interact with the SM field content. These massive dark photons can therefore decay to pairs of leptons, hadrons, or quarks, depending on their mass $m_{γ'}$. In this work, we discuss searches for dark photons in the mass range around and below one GeV at the LHeC and FCC-he colliders. The signal is giv…
We study the anomalous $W^+W^-γ$ couplings in performing the production of the W-pair through the process $e^- p\,\rightarrow\,e^-γ^*γ^* p\,\rightarrow\,e^-W^+W^-p$ at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he). We examine the pure hadronic, the semi-leptonic and the pure leptonic decay channels of the produced W-pair. We assume the center-of-mass energies of $\sqrt{s}=1.30$ and $1.98$ TeV and the integrated luminosities of 10-100 fb$^{-1}$ for the LHeC and the center-of-mass energies of $\sqrt{s}=3.46$ and $5.29$ TeV and the integrated …
Electron-proton ($e^-p$) colliders are an ideal laboratory to study common features of electron and quarks with production via electroweak bosons, leptoquarks, multi-jet final states and very forward physics, due to their impressive pseudorapidity coverage. In addition to these physics cases, there exist a broad Beyond the Standard Model (BSM) program aimed at exploring the capabilities of the LHeC [1] and FCC-he [2] for several New Physics scenarios. Although their centre-of-mass energy is down with respect to a $pp$ collider by a factor of $\sqrt{E_p/E_e} \sim 10~(30)$ for the LHeC (FCC-he),…
We examine the potential of the process $ep \rightarrow eγ^{*} γ^{*} p\rightarrow eτ\barτp$ at the Large Hadron Electron Collider (LHeC) and the Future Circular Hadron Electron Collider (FCC-he) to examine non-standard $τ\barτγ$ coupling in a model independent way by means of the effective Lagrangian approach. We perform pure leptonic and semileptonic decays for $τ^{-}τ^{+}$ production in the final state. Furthermore, we use $L = 10, 50, 100, 300, 500, 1000$ fb$^{-1}$ with at $\sqrt{s}=1.30, 1.98, 7.07, 10$ TeV and we consider systematic uncertainties of $δ_{sys}=0,5,10 \%$. The best sensitivi…
In this paper, a study is carried out on the $e^-p \to e^-γ^* p \to p W^+γν_e$ production to probe quartic $W^+W^-γγ$ couplings using 10, 100 ${\rm fb^{-1}}$ of $e^-p$ collisions data at $\sqrt{s}$= 1.30, 1.98 GeV at the Large Hadron electron Collider (LHeC) and 100, 1000 ${\rm fb^{-1}}$ with $\sqrt{s}$= 3.46, 5.29 GeV at the Future Circular Collider-hadron electron (FCC-he). Production cross-sections are determined for both at leptonic and hadronic decay channel of the $W$-boson. With the data from future $e^-p$ colliders, it is possible to obtain sensitivity measures at $95\%$ C.L. on the an…
Predictions of the top-pair production cross section in electron-proton (ep) collisions at the future circular collider hadron-electron (FCC-he) and the large hadron electron collider (LHeC) in the leading order (LO) and the next-to-leading order (NLO) approximations in perturbative quantum chromodynamics (QCD) are presented. Numerical results for the top structure functions and the ratio of structure functions are computed at the renormalization scale $μ^{2}=Q^{2}+4m^{2}_{t}$ in the collinear generalized double asymptotic scaling (DAS) approach. These results are presented in terms of the eff…
We examine the potential of the $e^-p \to e^-γ^*p \to e^-W^-q'X$ ($γ^*$ is Weizsacker-Willams photon) reaction to probe the non-standard $W^+W^-γ$ couplings at the Large Hadron electron Collider (LHeC) and the Future Circular Collider-hadron electron (FCC-he). We find $95\%$ confidence level bounds on the anomalous coupling $Δκ_γ$ and $λ_γ$ parameters in the view of effective Lagrangian approach with various values of the integrated luminosity. We assume center-of-mass energies of the electron-proton system $\sqrt{s}= 1.30, 1.98, 7.07, 10\hspace{0.8mm}{\rm TeV}$ and luminosities ${\cal L} = 10…
We study the cross-section of production of a single $W^-$ boson in association with a neutrino through the process $e^-p \to e^-γ^*p \to ν_eW^- p$. Additionally, we obtain the anomalous couplings $Δκ_γ$ and $λ_γ$ of the $W^+W^-γ$ vertex at the Large Hadron Electron Collider (LHeC) and the Future Circular Collider Hadron-Electron (FCC-he). The impact of the polarized beam due to the electron is also analyzed. Our best limits for $Δκ_γ$ and $λ_γ$ at the $95\%$ C.L. are: $Δκ_γ= \pm 0.0017$, $λ_γ= \pm 0.0053$ (unpolarized electron beam) and $Δκ_γ= \pm 0.0013$, $λ_γ= \pm 0.0046$ (polarized electro…
The LHeC and the FCC-he will open a new realm in our understanding of nuclear structure and the dynamics in processes involving nuclei, in an unexplored kinematic domain. We review some of the recent studies as shown in the update of the 2012 LHeC CDR, including the determination of nuclear parton densities in the framework of global fits and for a single nucleus, inclusive and exclusive diffraction and the unique capabilies of these high-energy colliders for probing QCD in the non-linear regime of phase space.
The proposed electron-proton collider experiments LHeC and FCC-eh at CERN are the highest resolution microscopes that can be realised in the present century and they would represent a really unique research facility. We exploit simulated neutral-current and charged-current deep-inelastic scattering data of the LHeC and the FCC-eh and examine their sensitivity for precision physics in the Electroweak sector of the Standard Model (SM), like the effective weak mixing angle $\sin^2θ_{\textrm{W},\ell}^\textrm{eff}$, or the light-quark weak-neutral-current couplings. Unique measurements are further …
The exclusive vector meson production in electron-ion collisions for the energies of the future colliders is investigated. We present predictions for the coherent and incoherent $ϕ$ and $J/ψ$ production in $eAu$ collisions considering the possible states of nucleon configurations in the nuclear wave function and taking into account of the non-linear corrections to the QCD dynamics. The cross sections and transverse momentum distributions are estimated assuming the energies of the Electron-Ion Collider (EIC), Large Hadron Electron Collider (LHeC) and Future Circular Collider (FCC-$eh$). Our res…
We calculate cross sections for inclusive dijet photoproduction in electron-nucleus scattering in the kinematics of the future EIC and the possible LHeC, HE-LHeC, and the FCC using next-to-leading order (NLO) perturbative QCD and nCTEQ15 and EPPS16 nuclear parton density functions (nPDFs). We make predictions for distributions in the dijet average transverse momentum ${\bar p}_T$, the average rapidity $\barη$, the observed nuclear momentum fraction $x_A^{\rm obs}$, and the observed photon momentum fraction $x_γ^{\rm obs}$. Comparing the kinematic reaches of the four colliders, we find that an …
Lepton-hadron colliders that use a proton or nucleus beam of current and future hadron colliders and let it collide with an electron beam from a newly built electron accelerator bring attractive physics programs which are strong and complementary to the hadron collider physics. Machine development for Energy Recovery LINAC and physics performance studies of such electron-hadron colliders, specifically the LHeC that uses the existing LHC beam and FCC-eh that is an option of Future Circular Collider program, are ongoing and reviewed in this article.
We have analyzed the prospects of observing the lightest CP-even neutral Higgs boson ($h_1$) via decays into $b \bar b$ pairs in the neutral and charged current production processes $e^- q \to e^- h_1 q$ and $e^- q\to ν_e h_1 q'$, respectively, at the planneded large Hadron electron Collider (LHeC), with an $e^-$ beam energy of 60 GeV and a $p$ beam energy of 7 TeV. We also focus on observing a relatively light charged Higgs boson ($h^{-}$) via its production mode $e^- b \to ν_e h^{-} b$ followed by the decays $h^{-} \to s \bar c + s \bar u$ at the upcoming Future Circular Collider in hadron-e…
The quartic gauge boson couplings that identify the strengths of the gauge boson self-interactions are exactly determined by the non-Abelian gauge nature of the Standard Model. The examination of these couplings at $ep$ collisions with high center-of-mass energy and high integrated luminosity provides an important opportunity to test the validity of the Standard Model and the existence of new physics beyond the Standard Model. The quartic gauge boson couplings can contribute directly to multi-boson production at colliders. Therefore, we examine the potential of the process $ep \rightarrow ν_{e…
The measurement of the Higgs quartic coupling modifier between a Higgs boson pair and a vector boson pair, $κ_{2V}$, is expected to be achieved from vector-boson fusion (VBF) production of a Higgs boson pair. However, this process involves another unmeasured parameter, the trilinear Higgs self-coupling modifier $κ_{λ}$. A sensitivity analysis should target both parameters. Since the LHC cannot avoid the gluon fusion pollution, which becomes severe for non-SM $κ_{λ}$, an electron-proton collider is more appropriate for the comprehensive measurement. In this regard, we study the VBF production o…
In this article, we consider the ratio of structure functions for heavy quark pair production at low values of $x$. The importance of this ratio for charm and beauty pair production is examined according to the Hadron Electron Ring Accelerator (HERA) data. The behavior of these ratios considers due to the hard-pomeron behavior of the gluon distribution function. The results are in good agreement with respect to the HERA data. Expanding this data to the range of new energies underscore the importance of these measurements for heavy quarks. The ratio of charm and beauty structure functions at th…
Considering the theoretical constraints on the charged-current (CC) non-standard neutrino interaction (NSI) parameters in a simplified $W'$ model, we study the sensitivities of the Large Hadron electron Collider (LHeC) and Future Circular Collider-hadron electron (FCC-he) to the CC NSI parameters through the subprocess $e^{-}q \to W' \to v_{e}q'$. Our results show that the LHeC with $\mathcal{L} = 100\;{\rm fb}^{-1}$ is a little more sensitive to the CC NSI parameters than that of the high-luminosity (HL) LHC, and the absolute values of the lower limits on the CC NSI parameters at the FCC-he a…
In this paper we study the electroproduction of open heavy flavor $D$- and $B$-mesons in the kinematics of future $ep$ colliders, such as the Electron Ion Collider (EIC), the Large Hadron electron Collider (LHeC) and the Future Circular Collider (FCC-he). We study in detail the dependence of the cross-sections on multiplicity of co-produced hadrons, in view of its possible sensitivity to contributions from multipomeron contributions, and discuss different observables which might be used for its study. According to our theoretical expectations, in $ep$ collisions the multipomeron contributions …
Though various extensions of the Standard Model with higher gauge group predict the existence of leptoquarks, none of them has been observed yet at any of the colliders. In this paper, we study the prospect of several past and future $e$-$p$ colliders like HERA, LHeC and FCC-he to detect them through radiation amplitude zero. We find that the leptoquarks showing zeros in the tree-level single-photon amplitudes at $e$-$p$ collider lie within the complementary set of those exhibiting zeros at $e$-$γ$ collider. We present a PYTHIA-based analysis for HERA, LHeC and FCC-he (run II) to detect the le…
We perform a search for beyond the standard model dimension-six operators relevant to the Higgs boson at the Large Hadron Electron Collider (LHeC) and the Future Circular Hadron Electron Collider (FCC-he). With a large amount of data (few ab$^{-1}$) and collisions at TeV scale, both LHeC and FCC-he provide excellent opportunities to search for the BSM effects. The study is done through the process $e^-p \to h j ν_e$ where the Higgs boson decays into a pair of $b \bar{b}$ and we consider the main sources of background processes including a realistic simulation of detector effects. For the FCC-h…
We summarize the quantitative results of our analysis [1] of top-pair photoproduction in semileptonic mode in $pe$ collisions at the LHeC and FCC-he. We define three photoproduction regions, based on the rapidity acceptance range of the electron tagger, that provide different degrees of sensitivity to top-quark effective couplings. We focus on the $t\bar{t}γ$ dipole couplings and the left-handed vector $tbW$ coupling, for which we determine limits at both energies in the different photoproduction regions. We find that the LHeC and FCC-he will yield tight direct bounds on top dipole moments, gr…
An approximately analysis study of the collinear approach for $t\overline{t}$ production at the Future Circular Collider hadron-electron (FCC-he) and the Large Hadron electron Collider (LHeC) is performed. To study heavy quark production processes, the collinear generalized double asymptotic scaling (DAS) approach in a wide rang of $Q^{2}$ is used. The reduced cross sections for top quark pair production at the FCC-he (for $Q^{2}{\geq}m^{2}_{t}$) and LHeC (for $Q^{2}{\leq}m^{2}_{t}$) center-of-mass energies at the high inelasticity are derived. These results may be considering for both the fut…
Non-Abelian structure of the Standard Model predicts the self-interactions of gauge bosons triple gauge couplings (TGC) and quartic gauge couplings (QGC). On the other hand, it is also important to determine the deviations from Standard Model (SM) via anomalous triple gauge couplings (aTGC) and anomalous quartic gauge couplings (aQGC) to test the nature of the Standard Model (SM) and to see the effects of new physics arising from the beyond standard model (BSM). In this study, we focus on the $e^-p \to j Zγν_e \to j (l^{+} l^{-})γν_e$ process to examine the $WWZγ$ anomalous quartic gauge coupl…
In this proceedings some studies on the prospects of single top production at the Large Hadron Electron Collider (LHeC) and double Higgs production at the Future Circular Hadron Electron Collider (FCC-he) shall be presented. In particular, we investigated the $tbW$ couplings via single top quark production with the introduction of possible anomalous Lorentz structures, and measured the sensitivity of the Higgs self coupling ($λ$) through double Higgs production. The studies are performed with 60 GeV electrons colliding with 7 (50) TeV protons for the LHeC (FCC-he). For the single top studies a…
In the present work, $k_T$-factorization formalism is applied to compute the exclusive dilepton production by timelike Compton scattering (TCS) in $eA$, $pA$ and $AA$ collisions. The nuclear effects are investigated considering heavy and light ions. The production cross section in terms of invariant mass and rapidity distribution of the lepton pair is shown. The analysis is done for electron-ion collisions at the Large Hadron-Electron Collider (LHeC), its high-energy upgrade (HE-LHeC) and at the Future Circular Collider (FCC) in lepton-hadron mode. Additionally, ultraperipheral heavy ion colli…
The future electron-proton collider proposals, LHeC and FCC-he, can deliver $\mathcal{O}$(TeV) center-of-mass energy collisions, higher than most of the proposed lepton accelerators, with $\mathcal{O}$(ab$^{-1}$) luminosity, while maintaining a much cleaner experimental environment as compared to the hadron machines. This unique capability of $e^- p$ colliders can be harnessed in probing BSM scenarios giving final states that look like hadronic noise at $pp$ machines. In the present study, we explore the prospects of detecting such a prompt signal having multiple soft jets at the LHeC. Such a …
In this work the $k_{\perp}$-factorization formalism is applied to compute the exclusive $Z^0$ boson photoproduction in $ep$ and $eA$ collisions. The study is also extended to $pp$ and $AA$ processes. The nuclear effects are investigated considering heavy and light ions. Analytical models for the unintegrated gluon distribution are taken into account and the corresponding theoretical uncertainty is quantified. The analysis is done for electron-ion collisions at the Large Hadron-Electron Collider (LHeC), its high-energy upgrade (HE-LHeC) and at the Future Circular Collider (FCC) in lepton-hadro…
We carry out a study in the approach of a dimension-8 effective field theory on the anomalous quartic $WWγγ$ couplings that arise from the process $pp \to Wγγ$ at the Future Circular Collider-hadron hadron (FCC-hh). The process is sensitive to the $WWγγ$ vertex, and future projections on the anomalous $f_ {M,i}/Λ^4$ and $ f_ {T,j}/Λ^4$ couplings can be put by measurements of $Wγγ$ production. We illustrate the physics opportunities and reach of the FCC-hh operating for a high integrated luminosity scenario of ${\cal L}=1, 5, 10, 30$ ${\rm ab}^{-1}$ of proton-proton collisions at a center-of-ma…
Construction of future electron-positron colliders (or dedicated electron linac) and muon colliders (or dedicated muon ring) tangential to Future Circular Collider (FCC) will give opportunity to utilize highest energy proton and nucleus beams for lepton-hadron and photon-hadron collisions. Luminosity values of FCC based ep, \mup, eA, \muA, \gammap and \gammaA colliders are estimated. Multi-TeV center of mass energy ep colliders based on the FCC and linear colliders (LC) are considered in detail. Parameters of upgraded versions of the FCC proton beam are determined to optimize luminosity of ele…
We perform an updated analysis on the searches for the anomalous FCNC Yukawa interactions between the top quark, the Higgs boson, and either an up or charm quark ($\rm tqh,\ q=u,\ c$). We probe the observability of the FCNC top-Higgs couplings through the processes $\rm e^- p\rightarrow ν_e \bar{t} \rightarrow ν_e h \bar{q}$ (signal.I) and $\rm \ e^- p \to ν_e h b$ (singal.II) at the proposed electron proton (ep) colliders, where the Higgs boson decays to a $\rm b\bar{b}$ pair. We find that at the high luminosity (1 $\rm ab^{-1}$) ep colliders where the electrons have a polarisation of $\rm 80…
In this talk we present a short overview of top physics at the electron-proton (ep) colliders. Currently, the proposed ep collider is the Large Hadron Electron Collider (LHeC), which is a combination of 60 GeV electron beam and 7 TeV proton beam of the LHC tunnel. This may be extended to Future Circular electron-hadron Collider (FCC-eh), which features a 60 GeV (or higher) electron beam with the 50 TeV proton beam from the Future Circular hadron Collider (FCC-hh). Selected topics include but not limited to top structure function, top parton distribution functions, top spin polarization, top el…
We present a sensitivity study on the cubic and quartic self couplings in double Higgs production via gluon fusion at hadron colliders. Considering the relevant operators in the Standard Model Effective Field Theory up to dimension eight, we calculate the dominant contributions up to two-loop level, where the first dependence on the quartic interaction appears. Our approach allows to study the independent variations of the two self couplings and to clearly identify the terms necessary to satisfy gauge invariance and to obtain UV-finite results order by order in perturbation theory. We focus on…
Triple gauge boson production provides a promising opportunity to probe the anomalous quartic gauge couplings in understanding the details of electroweak symmetry breaking at future hadron-hadron collider facilities with increasing center of mass energy and luminosity. In this paper, we investigate the sensitivities of dimension-8 anomalous couplings related to the $ZZγγ$ and $Zγγγ$ quartic vertices, defined in the effective field theory framework, via $pp\to Zγγ$ signal process with Z-boson decaying to charged leptons at the high luminosity phase of LHC (HL-LHC) and future facilities, namely …
We study the diffractive jet production in electron-ion collisions in the kinematical region where the mass $M_X$ of the diffractive final state is larger than $Q^2$. Based on parton saturation framework predictions are done for the kinematics of future or possible $eA$ machines as the EIC, LHeC, HE-LHeC and FCC-eA. We analyze the differential cross section as a function of jet (gluon) transverse momentum and from the experimental point of view this observable could be used to extract the saturation scale as a function of $x_{I\!\!P}$.
A popular framework for exploring Lorentz violation is the Standard Model Extension. This extension contains a large number of parameters that can be bounded in various experiments. Most studies, however, focus on the fermion or photon sector. Here, we consider Lorentz violation in the weak vector boson sector. The strongest bounds come from measurements of the asymmetry in Moller scattering. We study the bounds that can be obtained from future measurements of the parity violating asymmetry in deep inelastic electron-proton scattering at the EIC, the LHeC and the FCC-eh. For the FCC-eh, the bo…
The top quark flavor changing neutral current (FCNC) processes are extremely suppressed within the Standard Model (SM) of particle physics. However, they could be enhanced in a new physics model Beyond the Standard Model (BSM). The top quark FCNC interactions would be a good test of new physics at present and future colliders. Within the framework of the BSM models, these interactions can be described by an effective Lagrangian. In this work, we study tqgamma and tqZ effective FCNC interaction vertices through the process e-p->e-Wq+X at future electron proton colliders, projected as Large Hadr…
Future electron-proton collider proposals like the LHeC or the FCC-eh can supply 1/ab of collisions with a center-of-mass energy in the TeV range, while maintaining a clean experimental environment more commonly associated with lepton colliders. We point out that this makes electron-proton colliders ideally suited to probe BSM signatures with final states that look like "hadronic noise" in the high-energy, pile-up-rich environment of hadron colliders. We focus on the generic vector boson fusion production mechanism, which is available for all BSM particles with electroweak charges at mass scal…
