arXiv subjects

M. Köksal

Publications and source records attributed to M. Köksal.

At least 37 records · Page 2Linked to original sources

arXiv2021

Model-independent study on the anomalous $τ\barτγ$ couplings at the ILC

The potential of the process $γγ\rightarrow τ\barτγ$ is examined in a model-independent way using the effective Lagrangian approach for the ILC which is designed with standard configurations of 0.25 TeV/2000 fb$^{-1}$, 0.35 TeV/200 fb$^{-1}$ and 0.5 TeV/4000 fb$^{-1}$. The limits obtained for $\tilde{a}_τ$ and $\tilde{{d}_τ}$ parameters defining the anomalous $τ\barτγ$ couplings at $95\%$ confidence level and systematic uncertainties of $δ_{sys}=0,5,10 \%$ are compared with the experimental results. The best limits obtained without systematic error on the anomalous couplings are $-0.00082<\tilde{a}_τ<0.00050$ and $|\tilde{{d}_τ}|<3.5969 \times 10^{-18}$ $e\,cm$, respectively. Thus, our results show that $γγ$ collisions at the ILC lead to a remarkable improvement in the existing experimental limits on the anomalous magnetic and electric dipole moments of the tau lepton.

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arXiv2021

Study on the anomalous quartic $W^+W^-γγ$ couplings of electroweak bosons in $e^-p$ collisions at the LHeC and the FCC-he

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 anomalous $f_ {M,i}/Λ^4$ and $ f_ {T,i}/Λ^4$ couplings which are competitive with the limits obtained by the LHC, as well as with others limits reported in the literature. The production mode $e^-p \to e^-γ^* p \to p W^+γν_e $ in $e^-p$ collisions offers a window for study the quartic $W^+W^-γγ$ electroweak bosons couplings at the LHeC and the FCC-he, which provides a much cleaner collision environment than the LHC.

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arXiv2020

Model independent study for the anomalous $W^+W^-γ$ couplings at the future lepton-hadron colliders

The triple gauge couplings are completely defined by the non-Abelian gauge nature of the Standard Model, precision measurements of these couplings at the present and future colliders in this way provide a substantial opportunity to test the gauge structure of the Standard Model. Also, measurements of these couplings are sensitive to new physics beyond the Standard Model. In this context, these couplings can be described by an effective Lagrangian. Here, we have studied the potential of the future $μp$ colliders on the anomalous $WWγ$ interactions via the subprocess $γ^* p\,\rightarrow\,W^-ν_μ$. This subprocess has been generated through the main process $μp\,\rightarrow\,μγ^* p\,\rightarrow\,W^-ν_μp$ at the LHC-$μp$, the FCC-$μp$ and the SPPC-$μp$. For these reasons, the total cross sections have been obtained as a function of the anomalous $WWγ$ couplings. Also, we have been calculated the best constraints on $c_{WWW}$, $c_{W}$ and $c_{B}$ parameters that define the anomalous $WWγ$ interactions.

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arXiv2019

Probing the anomalous $tqγ$ couplings through single top production at the future lepton-hadron colliders

The measurements of the top quark flavor changing neutral current interactions are one of the most important goals of the top quark physics program in the present and the future collider experiments. These measurements provide direct information on non-standard interactions of the top quark. Within the framework of new physics beyond the Standard Model, these interactions can be defined by an effective Lagrangian. In this study, we have investigated the potential of the future $μp$ colliders on the top quark flavor changing neutral current interactions through the subprocesses $γq \rightarrow t \rightarrow W b$ where $q=u,c$. These subprocesses have been produced through the main reaction $μp \rightarrow μγp \rightarrow μW b X $ at the LHC$-μp$, the FCC$-μp$ and the SPPC-$μp$. For the main reaction, the total cross sections have been calculated as a function of the anomalous $ tqγ$ couplings. In addition, sensitivities on BR($t \rightarrow q γ$) at $95\%$ Confidence Level have been calculated. We obtain that the best constraints on BR($t \rightarrow q γ$) are at the order of 10$^{-7}$ which is four orders of magnitude better than the LHC's experimental results.

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arXiv2019

Anomalous quartic $WWγγ$ couplings in $ep$ collisions at the LHeC and the FCC-he

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 FCC-he, 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 $E_p = 50$ TeV, respectively. It is interesting to notice that the LHeC and the FCC-he will lead to model-independent limits on the anomalous quartic $WWγγ$ couplings which are one order of magnitude stringent than the CMS Collaboration limits, in addition to being competitive with other limits reported in the literature.

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arXiv2019

Projections for model-independent sensitivity estimates on top-quark anomalous electromagnetic couplings at the FCC-he

The measurement of the top-quark anomalous electromagnetic couplings is one of the most important goals of the top-quark physics program in the present and future collider experiments. This would provide direct information on the non-standard interactions of the top-quark. We study a top-quark pair production scenario at the Future Circular Collider Hadron-Electron (FCC-he) through $e^-p \to e^-γ^*γ^*p \to e^-t\bar t p$ collisions, which will provide information about sensitivities on anomalous $\hat a_V$ and $\hat a_A$ couplings at $95\%\hspace{0.8mm}C.L.$, and the possibility of probing new physics. Energy of the $e^-$ beams is taken to be $E_e=250\hspace{0.8mm}GeV$ and $500\hspace{0.8mm}GeV$ and the energy of the $p$ beams is taken to be $E_p=50\hspace{0.8mm}TeV$, with these energies the FCC-he may sensitivity estimates on top-quark electromagnetic dipole moments $\hat a_V$ and $\hat a_A$ of the order ${\cal O}(10^{-2}-10^{-1})$.

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arXiv2019

Probing model-independent limits on $W^+W^-γ$ triple gauge boson vertex at the LHeC and the FCC-he

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 electron beam) identifying the $W^-$ boson through the hadronic decay channel. In addition, the $e^-γ^* \to ν_eW^-$ collision is one of the clean, pure and simple process to investigate the $W^+W^-γ$ coupling without the complications of QCD backgrounds.

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arXiv2019

Model-independent limits for anomalous triple gauge bosons $W^+W^-γ$ coupling at the CLIC

We investigate the potential of the Compact Linear Collider (CLIC) to probe the anomalous $W^+W^-γ$ coupling in $γγ$, $γγ^*$ and $γ^*γ^*$ collisions through the processes $γγ\rightarrow W^+ W^-$, $e^+ γ\rightarrow e^+ γ^{*} γ\rightarrow e^+ W^- W^+$ and $e^+ e^-\rightarrow e^+ γ^{*} γ^{*} e^- \rightarrow e^+ W^- W^+ e^-$. We perform leptonic, semi-leptonic and hadronic decays channels for $W^+W^-$ production in the final state. Taking ${\cal L}=1\hspace{0.8mm}{\rm ab^{-1}}@ \sqrt{s}=0.380\hspace{0.8mm}{\rm TeV}$, ${\cal L}=2.5\hspace{0.8mm}{\rm ab^{-1}}@ \sqrt{s}=1.5\hspace{0.8mm}{\rm TeV}$ and ${\cal L}=5\hspace{0.8mm}{\rm ab^{-1}}@ \sqrt{s}=3\hspace{0.8mm}{\rm TeV}$, based on future CLIC data, the limits for $Δκ_γ$ and $λ_γ$ might reach up to ${\cal O}(10^{-5}-10^{-4})$ level in the most ideal with 5\hspace{0.8mm}${\rm ab^{-1}}$ set data, which shows a potential advantage compared to those from LHC, Tevatron and LEP data. Thus, our results represent that the processes $γγ\rightarrow W^+ W^-$, $e^+ γ\rightarrow e^+ γ^{*} γ\rightarrow e^+ W^- W^+$ and $e^+ e^-\rightarrow e^+ γ^{*} γ^{*} e^- \rightarrow e^+ W^- W^+ e^-$ at the CLIC are a very good prospect for probing the anomalous $W^+W^-γ$ couplings.

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arXiv2019

Sensitivity measuring expected on the electromagnetic anomalous couplings in the $t\bar tγ$ vertex at the FCC-he

In this paper, we consider the electroweak production cross-section of a single anti-top-quark, a neutrino and a photon via charged current through the $e^-p \to e^-\bar b \to \bar t ν_e γ\to \bar t(\to W^- \to (qq', l^- \barν_l)+b) ν_eγ$ signal. Further, we derived the sensitivity expected to the magnetic dipole moment $(\hat a_V)$ and the electric dipole moment $(\hat a_A)$ of the top-quark at the Future Circular Collider Hadron Electron (FCC-he). We present our study for $\sqrt{s}=7.07, 10\hspace{0.8mm}TeV$, ${\cal L}=50, 100, 300, 500, 1000\hspace{0.8mm}fb^{-1}$, $δ_{sys}=0, 3, 5\hspace{0.8mm}\%$ and $P_{e^-}=0\%, 80\%, -80\%$, respectively. We find that the sensitivity estimated on dipole moments of the top-quark is of the order of magnitude ${\cal O}(10^{-1})$ for both hadronic and leptonic decay modes of $W^-$: $\hat a_V=[-0.2308, 0.2204]$, $|\hat a_A|=0.2259$ at $95\%$ C.L. in the hadronic channel with unpolarized electron beam $P_{e^-}=0\%$. Our results with polarized electron beam for $P_{e^-}=80\%$ and $P_{e^-}=-80\%$ are $\hat a_V=[-0.3428, 0.3321]$, $|\hat a_A|=0.3371$ and $\hat a_V=[-0.2041, 0.1858]$, $|\hat a_A|=0.1939$ at $95\%$ C.L. in the hadronic channel. The corresponding results for the leptonic channel with $P_{e^-}=0\%, 80\% -80\%$ are $\hat a_V=[-0.3067, 0.2963]$, $|\hat a_A|=0.3019$, $\hat a_V=[-0.4563, 0.4456]$, $|\hat a_A|=0.4505$ and $\hat a_V=[-0.2695, 0.2512]$, $|\hat a_A|=0.2592$, respectively. The results for $\hat a_V$ and $\hat a_A$ in the leptonic channel are weaker by a factor of 0.75 than those corresponding to the hadronic channel. Given these prospective sensitivities we highlight that the FCC-he is potential top-quark factory that is particularly well suited to sensitivity study on its dipole moments and with cleaner environments.

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arXiv2019

Search for the electromagnetic moments of the $τ$ lepton in photon-photon collisions at the LHeC and the 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 sensitivity bounds obtained from the process $ep \rightarrow eγ^{*} γ^{*} p\rightarrow eτ\barτp$ on the anomalous couplings are $-0.0025<\tilde{a}_τ<0.0009$ and $|\tilde{{d}_τ}|<8.85 \times 10^{-18}\, e\,cm$, respectively. Therefore, our results show that the process $ep \rightarrow eγ^{*} γ^{*} p\rightarrow eτ\barτp$ at the LHeC and FCC-he are a very good prospect for probing the anomalous magnetic and electric dipole moments of the $τ$ lepton at $γ^{*} γ^{*}$ mode of the future $ep$ collider.

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arXiv2019

FCC-he sensitivity estimates on the anomalous electromagnetic dipole moments of the top-quark

In this paper, we study the production of a top-quark in association with a bottom-quark and a electron-neutrino at the Future Circular Collider Hadron Electron (FCC-he) to probe the sensitivity on its magnetic moment $(\hat a_V)$ and its electromagnetic dipole moment $(\hat a_A)$ through the process $e^-p \to e^-γp \to \bar t ν_e b p$. Assuming a large amount of collisions, as well as of data with cleaner environments, the FCC-he is an excellent option to study new physics, such as the $\hat a_V$ and $\hat a_A$. For our sensitivity study on $\hat a_V$ and $\hat a_A$, we consider center-of-mass energies $\sqrt{s}= 7.07, 10\hspace{0.8mm}TeV$ and luminosities ${\cal L}=50, 100, 300, 500, 1000\hspace{0.8mm}fb^{-1}$. In addition, we apply systematic uncertainties $δ_{sys}=0\%, 3\%, 5\%$ and we consider unpolarized and polarized electron beam. Our results show that the FCC-he is a very good perspective to probe the $\hat a_V$ and $\hat a_A$ at high-energy and high-luminosity frontier.

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arXiv2019

Feasibility at the LHC, FCC-he and CLIC for sensitivity estimates on anomalous $τ$-lepton couplings

In this paper, we present detailed studies on the feasibility at $pp$, $e^-p$ and $e^+e^-$ colliders for model-independent sensitivity estimates on the total cross-section and on the anomalous $τ^+τ^-γ$ interaction through the tau pair production channels $pp \to pτ\bar τγp$, $e^-p \to e^- τ\bar τγp$ and $e^+e^- \to e^+ τ\bar τγe^-$ at the $γ^*γ^* \to τ^+τ^-γ$ mode. Measurements of the anomalous couplings of the $τ$-lepton $\tilde{a}_τ$ and $\tilde{d}_τ$ provide an excellent opportunity to probing extensions of the Standard Model. We estimate the sensitivity at the $95\%$ Confidence Level, and we consider that the $τ$-lepton decays leptonically or semi-leptonically. We found that of the three considered colliders, the future CLIC at high energy and high luminosity should provide the best sensitivity on the dipole moments of the $τ$-lepton $\tilde a_τ= [-0.00128, 0.00105]$ and $ |\tilde{d}_τ({\rm ecm})|= 6.4394\times 10^{-18}$, which show a potential advantage compared to those from LHC and FCC-he.

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arXiv2018

The $μ^+μ^-$ collider to sensitivity estimates on the magnetic and electric dipole moments of the tau-lepton

Using the effective Lagrangian formalism, the anomalous magnetic and electric dipole moments of the tau-lepton in the $μ^{+}μ^{-} \rightarrow μ^{+}γ^{*} γ^{*} μ^{-}\rightarrow μ^{+}τ\barτμ^{-}$ process at the future muon colliders at the $\sqrt{s}=1.5, 3$ and $6$ TeV are investigated. In addition, the bounds at the $95\%$ confidence level on the dipole moments of the tau-lepton using different integrated luminosities are estimated. It is shown that the $μ^{+}μ^{-} \rightarrow μ^{+}γ^{*} γ^{*} μ^{-}\rightarrow μ^{+}τ\barτμ^{-}$ process leads to a remarkable improvement in the existing experimental bounds on the anomalous magnetic and electric dipole moments of the tau-lepton.

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arXiv2018

Analysis of the anomalous electromagnetic moments of the tau lepton in $γp$ collisions at the LHC

In this study, we investigate the potential of the process $pp\rightarrow pγ^{*} p\rightarrow p τ\barν_τq^{\prime} X$ at the LHC to examine the anomalous electromagnetic moments of the tau lepton. We obtain $95\%$ confidence level bounds on the anomalous coupling parameters with various values of the integrated luminosity and center-of-mass energy. The improved bounds have been obtained on the anomalous coupling parameters of electric and magnetic moments of the tau lepton $a_τ$ and $\vert$$d_τ$$\vert$ compared to the current experimental sensitivity bounds. The $γp$ mode of photon reactions at the LHC have shown that it has great potential for the electromagnetic dipole moments studies of the tau lepton.

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arXiv2018

Model-independent sensibility studies for the anomalous dipole moments of the $ν_τ$ at the CLIC based $γe^-$ colliders

To improve the theoretical prediction of the anomalous dipole moments of the $τ$-neutrino, we have carried out a study through the process $γe^- \to τ\barν_τν_e$, which represents an excellent and useful option in determination of these anomalous parameters. To study the potential of the process $γe^- \to τ\barν_τν_e$, we apply a future high-energy and high-luminosity linear electron-positron collider, such as the CLIC, with $\sqrt{s}=380, 1500, 3000\hspace{0.8mm}GeV$ and ${\cal L}=10, 50, 100, 200, 500, 1000, 1500, 2000, 3000\hspace{0.8mm}fb^{-1}$, and we consider systematic uncertainties of $δ_{sys}=0, 5, 10\%$. With these elements, we present a comprehensive and detailed sensitivity study on the total cross-section of the process $γe^- \to τ\barν_τν_e$, as well as on the dipole moments $μ_{ν_τ}$ and $d_{ν_τ}$ at the $95\%$ C.L., showing the feasibility of such process at the CLIC at the $γe^-$ mode with unpolarized and polarized electron beams.

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arXiv2017

Search for the anomalous electromagnetic moments of the tau lepton through electron-photon scattering at the CLIC

We have examined the anomalous electromagnetic moments of the tau lepton in the processes $e^{-}γ\to ν_eτ\barν_τ$ ($γ$ is the Compton backscattering photon) and $e^{-}e^{+} \to e^{-}γ^* e^{+} \to ν_{e}τ\barν_τe^+$ ($γ^*$ is the Weizsacker-Williams photon) with unpolarized and polarized electron beams at the CLIC. We have obtained 95$\%$ confidence level bounds on the anomalous magnetic and electric dipole moments for various values of the integrated luminosity and center-of-mass energy. Improved constraints of the anomalous magnetic and electric dipole moments have been obtained compared to the LEP sensitivity.

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arXiv2017

Improved sensitivity on the electromagnetic dipole moments of the top quark in $γγ$, $γγ^$ and $γ^γ^*$ collisions at the CLIC

We realize a phenomenological study to examine the sensitivity on the magnetic moment and electric dipole moment of the top quark through the processes $γγ\rightarrow t \bar{t}$, $e γ\rightarrow e γ^{*} γ\rightarrow e t \bar{t}$ and $e^{-} e^{+}\rightarrow e^{-} γ^{*} γ^{*} e^{+} \rightarrow e^{-} t \bar{t}e^{+}$ at the CLIC. We find that with a center-of-mass energy of the CLIC-1.4$\hspace{0.8mm}TeV$, integrated luminosity of ${\cal L}=1500\hspace{0.8mm}fb^{-1}$ and CLIC-3$\hspace{1mm}TeV$, integrated luminosity of ${\cal L}=2000\hspace{0.8mm}fb^{-1}$ with systematic uncertainties of $δ_{sys}=0, 5, 10\hspace{1mm}\%$ at the $95\%\hspace{1mm}C. L.$, it is possible the CLIC may put limits on the electromagnetic dipole moments of the top quark $\hat a_V$ and $\hat a_A$ with a sensitivity of ${\cal O}(10^{-3}-10^{-2})$. Therefore, we show that the sensitivity with the CLIC data is much greater than that for the LHC data.

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arXiv2017

Probe of the Anomalous Quartic Couplings with Beam Polarization at the CLIC

We have investigated the anomalous quartic couplings defined by the dimension-8 operators in semileptonic decay channel of the $e^{+}e^{-}\rightarrow ν_{e} W^{-} W^{+} \barν_{e}$ process for unpolarized and polarized electron (positron) beam at the Compact Linear Collider. We give the $95\%$ confidence level bounds on anomalous $\frac{f_{S0}}{Λ^{4}}$, $\frac{f_{S1}}{Λ^{4}}$ and $\frac{f_{T0}}{Λ^{4}}$ couplings for various values of the integrated luminosities and center-of-mass energies. The best sensitivities obtained on anomalous $\frac{f_{S0}}{Λ^{4}}$, $\frac{f_{S1}}{Λ^{4}}$ and $\frac{f_{T0}}{Λ^{4}}$ couplings through the process $e^{+}e^{-}\rightarrow ν_{e} W^{-} W^{+} \barν_{e}$ with beam polarization at $\sqrt{s}=3$ TeV and an integrated luminosity of $L_{int}=2000$ fb$^{-1}$ are $[-4.05;\, 3.67]\times 10^{-12}$ GeV$^{-4}$, $[-3.08; \, 2.12]\times 10^{-12}$ GeV$^{-4}$, $[-1.98; \, 0.64]\times 10^{-13}$ GeV$^{-4}$, which show improvement over the current bounds.

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