Search for electromagnetic properties of the neutrino in γe\gamma e and γγ\gamma\gamma collisions at CLIC

We have examined nonstandard $\gamma\nu\bar\nu$ and $\gamma\gamma\nu\bar\nu$ couplings via $\nu\bar\nu$ production in a $e\gamma$ and $\gamma\gamma$ collisions at the CLIC. We obtain 95% confidence level bounds on $\gamma\nu\bar\nu$ and $\gamma\gamma\nu\bar\nu$ couplings by considering the backscattered photon distribution function for incoming photons and Initial State Radiation (ISR) and Beamstrahlung (BS) effect for initial state electrons in the $e\gamma$ and $\gamma\gamma$ collider modes of linear collider. We indicate that the reaction $\gamma\gamma\to\nu\bar\nu$ provides more than 15 orders of magnitude improvement in neutrino-two photon couplings compared to LEP limits.Comment: 14 pages, 11 figures, to appear in Phys. Rev.

Probe of anomalous quartic WWZγWWZ\gamma couplings in the photon-photon collisions

In this paper, we examine the potentials of the processes $\gamma \gamma\rightarrow W^{+} W^{-}Z$ and $e^{+}e^{-} \rightarrow e^{+}\gamma^{*} \gamma^{*} e^{-} \rightarrow e^{+} W^{+} W^{-} Z e^{-}$ at the CLIC with $\sqrt{s}=0.5,1.5$ and $3$ TeV to investigate anomalous quartic $WWZ\gamma$ couplings by two different CP-violating and CP-conserving effective Lagrangians. We find $95\%$ confidence level limits on the anomalous coupling parameters at the three CLIC energies and various integrated luminosities. The best limits obtained from the process $\gamma \gamma\rightarrow W^{+} W^{-}Z$ on the anomalous $\frac{k_{0}^{W}}{\Lambda^{2}}$, $\frac{k_{c}^{W}}{\Lambda^{2}}$ and $\frac{k_{2}^{m}}{\Lambda^{2}}$ couplings defined by CP-conserving effective Lagrangians are $[-1.73;\, 1.73]\times 10^{-7}$ GeV$^{-2}$, $[-2.44;\, 2.44]\times 10^{-7}$ and $[-1.89; \, 1.89]\times 10^{-7}$ GeV$^{-2}$, while $\frac{a_{n}}{\Lambda^{2}}$ coupling determined by CP-violating effective Lagrangians is obtained as $[-1.74;\, 1.74]\times 10^{-7}$ GeV$^{-2}$. In addition, the best limits derived on $\frac{k_{0}^{W}}{\Lambda^{2}}$, $\frac{k_{c}^{W}}{\Lambda^{2}}$ and $\frac{k_{2}^{m}}{\Lambda^{2}}$ and $\frac{a_{n}}{\Lambda^{2}}$ from the process $e^{+}e^{-} \rightarrow e^{+}\gamma^{*} \gamma^{*} e^{-} \rightarrow e^{+} W^{+} W^{-} Z e^{-}$ are obtained as $[-1.09;\, 1.09]\times 10^{-6}$ GeV$^{-2}$, $[-1.54;\, 1.54]\times 10^{-6}$ GeV$^{-2}$, $[-1.18;\, 1.18]\times 10^{-6}$ and $[-1.04;\, 1.04]\times 10^{-6}$ GeV$^{-2}$, respectively.Comment: 33 pages, 27 figures, 4 tables, version to appear in JHE

Constraints on Higgs effective couplings in HννˉH\nu \bar{\nu} production of CLIC at 380 GeV

The potential of the $e^+e^-\to\nu \bar{\nu} H$ process in the first stage of CLIC considering center of mass energy of 380 GeV and assuming the baseline integrated luminosity of 500 fb$^{-1}$ is examined to probe CP conserving dimension-six operators in a model-independent Standard Model effective field theory framework. In the analysis, a detailed fast simulation on $e^+e^-\to\nu \bar{\nu} H$ signal processes and dominant backgrounds are performed including parton showering with PYTHIA and detector simulation based on ILD type detector with DELPHES in MadGraph. The obtained best limits on the $\bar{c}_{HB}$, $\bar{c}_{W}=- \bar{c}_{B}$ and $\bar{c}_{HW}$ are $[-4.82;1.53]\times10^{-2}$, $[-5.11;4.13]\times10^{-3}$ and $[-6.58;5.55]\times10^{-3}$, respectively.Comment: 13 pages, 6 figures, published versio

Analyzing the anomalous dipole moment type couplings of heavy quarks with FCNC interactions at the CLIC

In this study we examine both anomalous magnetic and dipole moment type couplings of a heavy quark via its single production with subsequent dominant Standard Model decay modes at the Compact Linear Collider (CLIC). The signal and background cross sections are analyzed for heavy quark masses 600 and 700 GeV. We make the analysis to delimitate these couplings as well as to find the attainable integrated luminosities or 3$\sigma$ observation limit.Comment: 13 pages, 10 figure