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M. Köksal

Publications and source records attributed to M. Köksal.

44 records · Page 3Linked to original sources
arXiv2016

Anomalous $WWγ$ couplings with beam polarization at the Compact Linear Collider

We study the anomalous $WWγ$ couplings at the Compact Linear Collider through the processes $e^{+}e^{-}\to W^+W^-$, $e^{-}e^{+} \to e^{-} γ^{*} e^{+} \to e^{+} ν_{e} W^-$ and $e^{-}e^{+}\to e^{-} γ^{*} γ^{*} e^{+} \to e^{-} W^+ W^- e^{+} $ $ (γ^{*}$ is the Weizsacker-Williams photon). We give the 95\% confidence level limits for unpolarized and polarized electron (positron) beam on the anomalous couplings for various values of the integrated luminosities and center-of-mass energies. We show that the obtained limits on the anomalous couplings through these processes can highly improve the current experimental limits. In addition, our limits with beam polarization are approximately two times better than the unpolarized case.

hep-ph↗
arXiv2015

Search for anomalous quartic $WWZγ$ couplings at the future linear $e^{+}e^{-}$ collider

In this paper, the potentials of two different processes $e^{+}e^{-}\rightarrow W^{-} W^{+}γ$ and $e^{+}e^{-} \rightarrow e^{+}γ^{*} e^{-} \rightarrow e^{+} W^{-} Z ν_{e}$ at the Compact Linear Collider (CLIC) are examined to probe the anomalous quartic $WWZγ$ gauge couplings. For $\sqrt{s}=0.5, 1.5$ and 3 TeV energies at the CLIC, $95\%$ confidence level limits on the anomalous coupling parameters defining the dimension-six operators are found via the effective Lagrangian approach in a model independent way. The best limits on the anomalous couplings $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$, $\frac{k_{2}^{m}}{Λ^{2}}$ and $\frac{a_{n}}{Λ^{2}}$ which can be achieved with the integrated luminosity of $L_{int}=590$ fb$^{-1}$ at the CLIC with $\sqrt{s}=3$ TeV are $[-8.80;\, 8.73]\times 10^{-8}$ GeV$^{-2}$, $[-1.53; \, 1.51]\times 10^{-7}$ GeV$^{-2}$, $[-3.75; \, 3.74]\times 10^{-7}$ GeV$^{-2}$ and $[-9.13;\,9.09]\times 10^{-7}$ GeV$^{-2}$, respectively.

hep-ph↗
arXiv2015

Anomalous quartic $ZZγγ$ couplings at the CLIC

We study the sensitivity to anomalous quartic $ZZγγ$ couplings through the processes $e^{+}e^{-}\rightarrow Z\, Z\, γ$, $e^{+}e^{-} \rightarrow e^{+}γ^{*} e^{-} \rightarrow e^{+} Z\, Z\, e^{-}$ and $e^{+}e^{-} \rightarrow e^{+}γ^{*} γ^{*} e^{-} \rightarrow e^{+}\, Z\, Z\, e^{-}$ at the CLIC. We find $95\%$ confidence level bounds on these coupling parameters defining by the dimension-six operators. The best bounds on the anomalous $ZZγγ$ couplings among the three processes are obtained from $e^{+}e^{-}\rightarrow Z\, Z\, γ$ at a center of mass energy of $3$ TeV and an integrated luminosity of $590$ fb$^{-1}$. We show that the best bounds obtained on both the anomalous coupling parameters are of the order of $10^{-8}$ GeV$^{-2}$, significantly improving the current bounds.

hep-ph↗
arXiv2015

Probe of anomalous quartic $WWZγ$ couplings in the photon-photon collisions

In this paper, we examine the potentials of the processes $γγ\rightarrow W^{+} W^{-}Z $ and $e^{+}e^{-} \rightarrow e^{+}γ^{*} γ^{*} e^{-} \rightarrow e^{+} W^{+} W^{-} Z e^{-}$ at the CLIC with $\sqrt{s}=0.5,1.5$ and $3$ TeV to investigate anomalous quartic $WWZγ$ 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 $γγ\rightarrow W^{+} W^{-}Z $ on the anomalous $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$ and $\frac{k_{2}^{m}}{Λ^{2}}$ 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 $\frac{a_{n}}{Λ^{2}}$ 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 $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$ and $\frac{k_{2}^{m}}{Λ^{2}}$ and $\frac{a_{n}}{Λ^{2}}$ from the process $e^{+}e^{-} \rightarrow e^{+}γ^{*} γ^{*} e^{-} \rightarrow e^{+} W^{+} W^{-} Z e^{-}$ 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.

hep-ph↗
arXiv2015

Analysis of anomalous quartic $WWZγ$ couplings in $γp$ collision at the LHC

Gauge boson self-couplings are exactly determined by the non-Abelian gauge nature of the Standard Model (SM), thus precision measurements of these couplings at the LHC provide an important opportunity to test the gauge structure of the SM and the spontaneous symmetry breaking mechanism. It is a common way to examine the physics of anomalous quartic gauge boson couplings via effective Lagrangian method. In this work, we investigate the potential of the process $pp\rightarrow pγp\rightarrow p W Z q X$ to analyze anomalous quartic $WWZγ$ couplings by two different CP-violating and CP-conserving effective Lagrangians at the LHC. We calculate $95\%$ confidence level limits on the anomalous coupling parameters with various values of the integrated luminosity. Our numerical results show that the best limits obtained on the anomalous couplings $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$, $\frac{k_{2}^{m}}{Λ^{2}}$ and $\frac{a_{n}}{Λ^{2}}$ at $\sqrt{s}=14$ TeV and an integrated luminosity of $L_{int}=100$ fb$^{-1}$ are $[-1.37;\, 1.37]\times 10^{-6}$ GeV$^{-2}$, $[-1.88; \, 1.88]\times 10^{-6}$ GeV$^{-2}$, $[-6.55; \, 6.55]\times 10^{-7}$ GeV$^{-2}$ and $[-2.21;\,2.21]\times 10^{-6}$ GeV$^{-2}$, respectively. Thus, $γp$ mode of photon-induced reactions at the LHC highly improves the sensitivity limits of the anomalous coupling parameters $\frac{k_{0}^{W}}{Λ^{2}}$, $\frac{k_{c}^{W}}{Λ^{2}}$, $\frac{k_{2}^{m}}{Λ^{2}}$ and $\frac{a_{n}}{Λ^{2}}$.

hep-ph↗
arXiv2014

Analysis of excited neutrinos at the CLIC

We analyze the single and pair production of excited neutrinos at the CLIC through the processes $e^{+}e^{-}\rightarrow ν^{*} \barν$, $e^{+}e^{-} \rightarrow e^{+}γ^{*} e^{-} \rightarrow e^{+} ν^{*} W^{-}$, and $e^{+}e^{-} \rightarrow e^{+}γ^{*} γ^{*} e^{-} \rightarrow e^{+} ν^{*} \barν^{*} e^{-}$ ($γ^{*}$ is the Weizsacker-Williams photon). We examine comprehensively the excited neutrino signal and corresponding backgrounds to obtain limits on excited neutrino mass for various values of the integrated luminosity and center-of-mass energy. We show that the obtained bounds are more restricted than current experimental bounds.

hep-ph↗
arXiv2014

Anomalous $tqγ$ couplings in $γp$ collision at the LHC

We have examined the constraints on the anomalous $tqγ$ ($q=u,c$) couplings through the process $pp\to pγp\to pWbX$ at the LHC by considering three forward detector acceptances: $0.0015< ξ< 0.5$, $0.0015< ξ<0.15$ and $0.1< ξ< 0.5$. The sensitivity bounds on the anomalous couplings have been obtained at the $95%$ confidence level in a model independent effective lagrangian approach. We have found that the bounds on these couplings can be highly improved compared to current experimental bounds.

hep-ph↗