Probing physics beyond the standard model through neutrino-electron scatterings

Bilmiş, Selçuk
Neutrino interactions are well explained with the electroweak theory. Hence, as an alternative to collider experiments, new physics can be searched in neutrino exper iments as well. Using the neutrino-electron scattering data taken by several experi ments (TEXONO, GEMMA, LSND, CHARM II, BOREXINO), which were chosen according to their incoming neutrino energy as well as recoil energy of the electron, possible effects on the neutrino scattering data originating from the presence of non commutativity in space as well as the existence of a hidden sector in the form of dark photon have been studied. Once QED is extended into non-commutative space, coupling of neutral particles to photons becomes possible at tree level. Using this new vertex, contribution to the cross section is calculated and bounds for the non-commutative energy scale ΛNC are set. We find that the results from CHARM II experiments give the stringent bounds as ΛNC > 3.3 TeV at 95% confidence level and improve the bounds over the colliderexperiments. In the second part of the thesis, as an alternative scenario, the effects of the hidden sector through a light gauge boson A0, associated with a group U(1)B−L is searched in the neutrino electron scattering experiments. This new gauge boson can interact with neutrinos at tree level even though it has no charge, hence named as dark photon. The bounds are set for the mass of the dark photon mA0 and the coupling constant gB−L. The exclusion plot at the 90% C.L. for the mA0− gB−L plane is plotted. It is shown that the interference term can not be neglected and improves the bounds. Our results provide more stringent bounds to some regions of the parameter space.


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Quantum Chromodynamics(QCD) is part of the Standard Model(SM) that describes the interaction of fundamental particles. In QCD, due to the fact that strong coupling constant is large at low energies, perturbative approaches do not work. For this reason, non-perturbative approaches have to be used for studying the properties of hadrons. Among several non-perturbative approaches, QCD sum rules is one of the reliable methods which is applied to understand the properties of hadrons and their interactions.\ In th...
Modified Superformula Contours Optimized via Genetic Algorithms for Exponentially Converging 2D Solutions of MFIE
Guler, Sadri; Onol, Can; Ergül, Özgür Salih; Sever, Emrah; Dikmen, Fatih; Tuchkin, Yury A. (2017-05-25)
An infinitely smooth parametrical representation with derivatives of all orders is used, resulting into exponentially converging solutions of magnetic field integral equation (MFIE) in 2D either for TM or TE polarized excitations. A version of superformula modified for this purpose has been subject to optimization of its parameters via genetic algorithms to provide smooth parameterization for a desired boundary in two-dimensional problems. The organization of the MFIE kernel and convergence of the solution ...
Fast-Multipole-Method Solutions of New Potential Integral Equations
Gür, Uğur Meriç; Karaosmanoglu, Bariscan; Ergül, Özgür Salih (2017-09-27)
A recently introduced potential integral equations for stable analysis of low-frequency problems involving dense discretizations with respect to wavelength are solved by using the fast multipole method (FMM). Two different implementations of FMM based on multipoles and an approximate diagonalization employing scaled plane waves are developed and used for rigorous solutions of low-frequency problems. Numerical results on canonical problems demonstrate excellent stability and solution capabilities of both imp...
DERELI, T; TUCKER, RW (IOP Publishing, 1994-10-01)
We discuss how theories of dilaton gravity can be constructed in terms of a torsionfree but non-metric-compatible connection and explore the nature of connection-induced dilaton couplings to gravity when the theory is reformulated in terms of the Levi-Civita connection. Exact classical solutions are presented in the context of a string-inspired dilaton model in two dimensions.
Studies of Charm Quark Diffusion inside Jets Using Pb-Pb and pp Collisions at root s(NN)=5.02 TeV
Sirunyan, A. M.; et. al. (American Physical Society (APS), 2020-09-01)
The first study of charm quark diffusion with respect to the jet axis in heavy ion collisions is presented. The measurement is performed using jets with p(T)(jet) > 60 GeV/c and D-0 mesons with p(T)(D) > 4 GeV/c in lead-lead (Pb-Pb) and proton-proton (pp) collisions at a nucleon-nucleon center-of-mass energy of root s(NN) = 5.02 TeV, recorded by the CMS detector at the LHC. The radial distribution of D-0 mesons with respect to the jet axis is sensitive to the production mechanisms of the meson, as well as t...
Citation Formats
S. Bilmiş, “Probing physics beyond the standard model through neutrino-electron scatterings,” Ph.D. - Doctoral Program, Middle East Technical University, 2016.