arXiv subjects

Mehmet Demirci

Publications and source records attributed to Mehmet Demirci.

10 recordsLinked to original sources

arXiv2026

Solar Neutrino Probes of Light New Physics: Updated Limits from LUX-ZEPLIN Experiment

The recent low-energy electron recoil (ER) results reported by the LUX-ZEPLIN (LZ) experiment have established the most stringent constraints to date on new physics scenarios, specifically for solar axion-like particles with keV-scale masses and mirror dark matter. Motivated by this enhanced sensitivity and the resulting restrictive limits, our present work focuses on probing light mediator models via elastic neutrino-electron scattering induced by solar neutrinos. We specifically consider two broad classes of new physics scenarios: (i) universal light mediator models consistent with Lorentz invariance, including scalar, vector, and tensor interactions, and (ii) anomaly-free leptophilic $U(1)'$ gauge extensions featuring a new vector mediator associated with the $L_e-L_μ$, $L_e-L_τ$, $L_μ-L_τ$, and $L_e+2L_μ+2L_τ$ symmetries. By incorporating contributions from these interactions into the neutrino-electron scattering cross-section and utilizing the most precise solar neutrino flux predictions, we analyze the latest LZ ER datasets. We report novel constraints on the coupling-mass parameter space for these models. Furthermore, we contextualize our findings by comparing them with established bounds from various laboratory, cosmological, and astrophysical sources. Our analysis demonstrates that LZ data provide significantly improved limits in previously unconstrained regions of the parameter space.

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arXiv2025

Reinterpretation and preservation of data and analyses in HEP

Data from particle physics experiments are unique and are often the result of a very large investment of resources. Given the potential scientific impact of these data, which goes far beyond the immediate priorities of the experimental collaborations that obtain them, it is imperative that the collaborations and the wider particle physics community publish and preserve sufficient information to ensure that this impact can be realised, now and into the future. The information to be published and preserved includes the algorithms, statistical information, simulations and the recorded data. This publication and preservation requires significant resources, and should be a strategic priority with commensurate planning and resource allocation from the earliest stages of future facilities and experiments.

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arXiv2025

Probing light mediators with recent PandaX-4T low energy electron recoil data

Neutrinos elastically scattered off atomic electrons offer a unique opportunity to probe the Standard Model (SM) and beyond SM physics. In this work, we examine the new physics effects of light mediators through elastic neutrino-electron scattering using solar neutrinos at the low energy range of PandaX-4T. These mediators, with a mass less than $1$ GeV, are common properties of extensions to the SM. Accordingly, we consider universal light mediator models involving scalar, vector, and tensor interactions allowed by Lorentz invariance, and the anomaly-free $U(1)'$ extensions of the SM with a new vector mediator such as the $L_e-L_μ$, $L_e-L_τ$ and $L_μ-L_τ$ gauge models in which the charges are exclusively leptonic. The new physics effects are analyzed by embedding each model into the SM process using solar neutrino flux. We obtain novel constraints on the coupling-mass plane of these models from the latest Run0 and Run1 datasets of the PandaX-4T experiment. We also compare our results with other limits derived from various terrestrial and astrophysical experiments. Our analysis results reveal more stringent limits in some regions of parameter space.

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arXiv2024

Probing active-sterile neutrino transition magnetic moment on coherent elastic solar neutrino-nucleus scattering

In the presence of a transition magnetic moment between active and sterile neutrinos, sterile neutrinos could be produced by neutrino beams electromagnetically upscattering on nuclei. We study the active-sterile neutrino transition magnetic moment through this upscattering in the coherent elastic neutrino-nucleus scattering process induced by solar neutrinos. We place new limits on the transition magnetic moment-sterile neutrino mass plane using the latest data from the CDEX-10 experiment. We also provide projected sensitivities for future measurements. We observe that the projected sensitivities could cover some regions of the parameter space which were previously unexplored for the sterile neutrino mass up to $\sim$10 MeV.

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arXiv2023

Solar neutrino constraints on light mediators through coherent elastic neutrino-nucleus scattering

We investigate new physics with light-neutral mediators through coherent elastic neutrino-nucleus scattering (CE$ν$NS) at low energies. These mediators, with a mass of less than $1$ GeV, are common properties for extensions of the Standard Model (SM). We consider general scalar, vector, and tensor interactions allowed by Lorentz invariance and involve universal light mediators accordingly. In addition, we study an additional vector gauge boson with an associated $U(1)'$ gauge group for a variety of models including $U(1)_{B-L}$, $U(1)_{B-3L_e}$, $U(1)_{B-3L_μ}$, and $U(1)_{B-3L_τ}$. These models differ in the fermion charges, which determine their contributions within the CE$ν$NS process. The effects of each model are investigated by embedding them in the SM process using solar neutrino flux. We derive new limits on the coupling-mass plane of these models from the latest CDEX-10 data. We also present projected sensitivities involving the future experimental developments for each model. Our results provide more stringent constraints in some regions, compared to previous works. Furthermore, the projected sensitivities yield an improvement of up to one order of magnitude.

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arXiv2023

Arbitrary $\ell$-state solutions of the Klein-Gordon equation with the Eckart plus a class of Yukawa potential and its non-relativistic thermal properties

We report bound state solutions of the Klein Gordon equation with a novel combined potential, the Eckart plus a class of Yukawa potential, by means of the parametric Nikiforov-Uvarov method. To deal the centrifugal and the coulombic behavior terms, we apply the Greene-Aldrich approximation scheme. We present any $\ell$-state energy eigenvalues and the corresponding normalized wave functions of a mentioned system in a closed form. We discuss various special cases related to our considered potential which are utility for other physical systems and show that these are consistent with previous reports in literature. Moreover, we calculate the non-relativistic thermodynamic quantities (partition function, mean energy, free energy, specific heat and entropy) for the potential model in question, and investigate them for a few diatomic molecules. We find that the energy eigenvalues are sensitive with regard to the quantum numbers $n_r$ and $\ell$ as well as the parameter $δ$. Our results show that energy eigenvalues are more bounded at either smaller quantum number $\ell$ or smaller parameter $δ$.

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arXiv2022

Beam polarization effects on Z-boson pair production at electron-positron colliders: a full one-loop analysis

We present high-precision predictions for Z boson-pair production via electron-positron collisions by taking into account a full set of one-loop order scattering amplitudes, i.e., electroweak (EW) corrections together with soft and hard QED radiation. We provide a detailed numerical evaluation, from full EW corrections to pure QED corrections, specifically focusing on the effect of initial beam polarization on production rate. The left-right asymmetry and angular distributions are also presented. The radiative corrections are largely affected by initial beam polarizations. We get an improvement as around three times with completely polarized beams of $e^-_L$ and $e^+_R$. We find that the radiative corrections can sizably modify the production rate, typically yielding a total relative correction up to a few tens of a percent. This imply that the full EW corrections are required for $e^- e^+ \to ZZ$ to match with percent level accuracy.

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arXiv2021

One-loop electroweak radiative corrections to charged lepton pair production in photon-photon collisions

We provide high-precision predictions for muon-pair and tau-pair productions in a photon-photon collision by considering a complete set of one-loop-level scattering amplitudes, i.e., electroweak (EW) corrections together with soft and hard QED radiation. Accordingly, we present a detailed numerical discussion with particular emphasis on the pure QED corrections as well as genuinely weak corrections. The effects of angular and initial beam polarisation distributions on production rates are also discussed. An improvement is observed by a factor of two with oppositely polarized photons. Our results indicate that the one-loop EW radiative corrections enhance the Born cross section and the total relative correction is typically about ten percent for both production channels. It appears that the full EW corrections to $γγ\to \ell^- \ell^+$ are required to match a percent level accuracy.

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arXiv2020

Precise predictions for charged Higgs boson pair production in photon-photon collisions

The charged Higgs pair production via photon-photon collisions is investigated in the framework of two Higgs doublet model (2HDM), taking into account a full set of one-loop-level scattering amplitudes, i.e., including electroweak (EW) corrections together with soft and hard QED radiation. The numerical evaluation is carried out for three different scenarios, so-called non-alignment, low-$m_H$ and short-cascade, defined in the presence of the up-to-date experimental constraints and consistent with theoretical constraints as well. The total cross sections of $γγ\rightarrow H^{-}H^{+}$ are scanned over the plane ($m_{ϕ^0},\sqrt{s}$), where $ϕ^0$ is $h^0$ for low-$m_{H^0}$ scenario and $H^0$ for other two scenarios. The regions of the parameter space in which the production rates are sufficiently large are highlighted for each scenario. The production rates in different polarization collision modes of initial beams are also discussed. It can be enhanced up to two-times by oppositely polarized photons at high energies and right-handed polarized photons at low energies. Furthermore, decay channels of the charged Higgs boson are examined for each scenario. It is observed that the one-loop EW corrections, i.e., the virtual plus real radiation corrections, reduce the tree-level cross sections and the relative correction is typically in the range of $-10\%$ to $-30\%$, depending on model parameters.

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arXiv2019

Associated production of Higgs boson with a photon at electron-positron colliders

A complete one-loop prediction for the single production of the neutral Higgs bosons in association with a photon in electron-positron collisions is presented in the framework the minimal supersymmetric standard model (MSSM), paying special attention to the individual contribution from each type of diagram. This process has no amplitude at tree level and is hence directly sensitive to one-loop impacts and the underlying dynamics of Higgs. To investigate the effect of the new physics, four different scenarios, which include a Higgs boson with mass and couplings consistent with those of the discovered Higgs boson and a considerable part of parameter space allowed by the bounds from the searches for additional Higgs bosons and sparticles, are chosen in the MSSM. The dependence of the cross section in both the standard model(SM) and MSSM on the center-of-mass energy is examined by considering the polarizations of the initial electron and positron beams. The effect of individual contributions from each type of one-loop diagram on the total cross section is also investigated in detail. Furthermore, the total cross sections of $e^- e^+ \rightarrow γh^0$ as well as $e^- e^+ \rightarrow γA^0$ are scanned over the plane $m_A-\tanβ$ for each scenario. The full one-loop contributions are crucial for the analysis of beyond the SM physics at a future electron-positron collider.

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