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M. Yilmaz

Publications and source records attributed to M. Yilmaz.

17 recordsLinked to original sources
arXiv2016

Photometric, Spectroscopic and Orbital Period Study of Three Early Type Semi-detached Systems: XZ Aql, UX Her and AT Peg

In this paper we present a combined photometric, spectroscopic and orbital period study of three early-type eclipsing binary systems: XZ Aql, UX Her, and AT Peg. As a result, we have derived the absolute parameters of their components and, on that basis, we discuss their evolutionary states. Furthermore, we compare their parameters with those of other binary systems and with the theoretical models. An analysis of all available up-to-date times of minima indicated that all three systems studied here show cyclic orbital changes, their origin is discussed in detail. Finally, we performed a frequency analysis for possible pulsational behavior and as a result we suggest that XZ Aql hosts a δ Scuti component.

astro-ph.SR↗
arXiv2014

Photometric analysis of overcontact binaries AK Her, HI Dra, V1128 Tau and V2612 Oph

We analyze new, high quality multicolor light curves of four overcontact binaries: AK Her, HI Dra, V1128 Tau and V2612 Oph, and determine their orbital and physical parameters using the modeling program of G. Djurasevic and recently published results of radial velocity studies. The achieved precision in absolute masses is between 10 and 20%, and in absolute radii between 5 and 10%. All four systems are W UMa type binaries with bright or dark spots indicative of mass and energy transfer or surface activity. We estimate the distances and the ages of the systems using the luminosities computed through our analysis, and perform an O-C study for V1128 Tau, which reveals a complex period variation that can be interpreted in terms of mass loss/exchange and either the presence of the third body, or the magnetic activity on one of the components. We conclude that further observations of these systems are needed to deepen our understanding of their nature and variability.

astro-ph.SR↗
arXiv2014

Beam Dynamical Evolutions in a Solenoid Channel: A Review

Today a linear particle accelerator (linac), in which electric and magnetic fields are of vital importance, is one of the popular energy generation sources like Accelerator Driven System (ADS). A multipurpose, including primarily ADS, proton linac with energy of ~2 GeV is planned to constitute within the Turkish Accelerator Center (TAC) project collaborated by more than 10 Turkish universities. A Low Energy Beam Transport (LEBT) channel with two solenoids is a subcomponent of this linac. This solenoid channel transports the proton beam ejected by a proton source, and matches it with the Radio Frequency Quadrupole (RFQ) that is a subcomponent just after the LEBT. These solenoid magnets are used as focusing element to get the beam divergence and emittance growth under control. This paper includes settings of the LEBT solenoids with regard to beam dynamics, which investigates the beam particles motion in particle accelerators, for TAC proton linac done by using a beam dynamics simulation code PATH MANAGER. Furthermore, the simulation results have been interpreted analytically.

physics.gen-ph↗
arXiv2014

Beam Dynamics Design and Electromagnetic Analysis of 3 MeV RFQ for TAC Proton Linac

A beam dynamics design of 352.2 MHz Radio-Frequency Quadrupole (RFQ) of Turkish Accelerator Center (TAC) project which accelerates continuous wave (CW) proton beam with 30 mA current from 50 keV to 3 MeV kinetic energy has been performed in this study. Also, it includes error analysis of the RFQ in which some fluctuations have been introduced to input beam parameters to see how the output beam parameters are affected, two-dimensional (2-D) and three-dimensional (3-D) electromagnetic structural design of the RFQ to obtain optimum cavity paramaters that agree with the ones of the beam dynamics. The beam dynamics and error analysis of the RFQ have been done by using LIDOS.RFQ. Electromagnetic design parameters have been obtained by using SUPERFISH for 2-D cavity geometry and CST Microwave Studio for 3-D cavity geometry.

physics.acc-ph↗
arXiv2014

Design and Optimization of Low Energy Beam Transport for TAC Proton Facility

In this study, a low energy beam transport (LEBT) channel for the proton linac section of the Turkish Accelerator Center (TAC) has been designed by using TRAVEL code. Commonly used LEBT including two focusing solenoid magnets will transport and match the H- beam from a volume source to RFQ. In the beam dynamics simulations of such a LEBT line, 95% space-charge compensation (SCC) has been considered in this study. We aimed to find out the determination of our RFQ input parameters that gives the best possible beam quality at the entrance of the RFQ using beam collimator in the LEBT line as an alternative way. In this way, we have acquired the best possible beam quality on RFQ input plane as well as optimizing the LEBT line.

physics.acc-ph↗
arXiv2012

A Low Energy Beam Transport Design with high SCC for TAC Proton Accelerator

In this study, a low energy beam transport (LEBT) channel for the proton linac section of the Turkic Accelerator Complex (TAC) has been designed by using TRACE 2D and TRAVEL codes. The LEBT channel is located between an ion source and a radio frequency quadrupole (RFQ) structure. The aims of the design studies are perfect matching between input and output beams with two solenoid magnets, small emittance growth and sufficient space for beam diagnostics. Total length of such LEBT channel is about 1.3 m. The current of H- ion beam from ion source is 80 mA. In the beam dynamical simulations, we have taken into account some space charge compensation (SCC) factors between %93.75 and %100. The results of both codes have been compared for the selected SCC factors. Additionally, beam aperture study for % 95 SCC factor has been done to discard unwanted particles and increase the beam brightness.

physics.acc-ph↗
arXiv2012

A Search for pair production of the LSP $\tilde{ν_τ}$ at the CLIC via RPV Decays

In this work we consider pair production of LSP tau-sneutrinos at the Compact Lineer Collider. We assume that tau-sneutrinos decays in to e\textmu pair via RPV interactions. Backgroundless subprocess $e{}^{-}e^{+}\rightarrow\tildeν\bar{\tildeν}\rightarrowμ^{+}μ^{+}e^{-}e^{-}(μ^{-}μ^{-}e^{+}e^{+})$ is analyzed in details. Achievable limits on $Br\,(\tildeν_τ\rightarrowμe)$ at $3σ$ and $5σ$ CL are obtained depending on $\tilde{ν_τ}$ mass.

hep-ph↗
arXiv2010

Physical parameters of close binaries QX Andromedae, RW Comae Berenices, MR Delphini, and BD +07{\circ} 3142

Aims. We analyze new multicolor light curves and recently published radial velocity curves for close binaries QX And, RW Com, MR Del, and BD +07{\circ} 3142 to determine the physical parameters of the components. Methods. The light curves are analyzed using a binary star model based on Roche geometry to fit the photometric observations. Spectroscopic parameters, such as the mass ratios and spectral types, were taken from recent spectroscopic studies of the systems in question. Results. Our findings provide consistent and reliable sets of stellar parameters for the four studied binary systems. Of particular interest is the BD +07{\circ} 3142 system, since this is the first analysis of its light curves. We find that it is an overcontact binary of W UMa type and W subtype, and that each component has a large cool spot in the polar region. QX And is an A subtype, and RW Com a W subtype W UMa binary, and in both systems we find a bright spot in the neck region between the components. MR Del is a detached binary with a complex light curve that we could model with two cool spots on the hotter component.

astro-ph.SR↗
arXiv2007

Photoproduction at collider energies: from RHIC and HERA to the LHC

We present the mini-proceedings of the workshop on ``Photoproduction at collider energies: from RHIC and HERA to the LHC'' held at the European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*, Trento) from January 15 to 19, 2007. The workshop gathered both theorists and experimentalists to discuss the current status of investigations of high-energy photon-induced processes at different colliders (HERA, RHIC, and Tevatron) as well as preparations for extension of these studies at the LHC. The main physics topics covered were: (i) small-$x$ QCD in photoproduction studies with protons and in electromagnetic (aka. ultraperipheral) nucleus-nucleus collisions, (ii) hard diffraction physics at hadron colliders, and (iii) photon-photon collisions at very high energies: electroweak and beyond the Standard Model processes. These mini-proceedings consist of an introduction and short summaries of the talks presented at the meeting.

hep-ph↗
arXiv2006

The single production of the lightest E6 isosinglet quark at the LHC

We study the jet associated production of the new quarks predicted by the $E_{6}$ GUT model at the LHC. Generator level considerations are made for different mass values of the lightest of the new quarks to investigate its discovery potential and the prospects for obtaining its mixing angle to the Standard Model quarks. We find that after 100 fb$^{-1}$ of data taking, it is possible to discover the new quark with a significance more than 5$σ$ up to a mass of 1500 GeV. If no discovery is made, it is possible to constrain the mass vs quark mixing angle plane.

hep-ex↗
arXiv2006

Prospects to search for E6 isosinglet quarks in ATLAS

We consider pair production of new down-type isosinglet quarks originating from E_{6}, which is the favorite gauge symmetry group in superstring inspired GUT models. The study concentrates on the possibility of observing the pair production of the lightest of the new quarks, D, in the ATLAS detector at the forthcoming LHC accelerator, in the channel D\bar{D}\to ZjZj . Both signal and background events are studied using tree level event generators based on Monte Carlo techniques. The detector effects are taken into account using the ATLAS fast simulation tool, ATLFAST. It is shown that ATLAS can observe the D quark within the first year of low luminosity LHC operation if its mass is less than 650 GeV. For the case of two years of full luminosity running, 1 TeV can be reached with about three sigma significance.

hep-ex↗
arXiv2005

The Status of Turkic Accelerator Complex Proposal

Recently, the Turkic Accelerator Complex (TAC) is proposed as a regional facility for accelerator based fundamental and applied research. The complex will include linac on ring type electron-positron collider as a phi, charm and tau factory, linac based free electron laser (FEL), ring based third generation synchrotron radiation (SR) source and a few GeV proton accelerator. Preliminary estimations show that integral luminosity of hundred inverse femto-barns per year can be achieved for factory options. The FEL facility is planned to obtain laser beam between IR and soft X-ray region. In addition, SR facility will produce photon beams in UV and X-ray region. The proton accelerator will give opportunity to produce muon and neutron beams for applied research. The current status of the conceptual study of the complex is presented.

physics.acc-ph↗
arXiv2003

The Potential of the Linac-Ring Type Colliders for Particle and Nuclear Physics

Linac-ring type colliders will open new windows for both energy frontier and particle factories. Concerning the first direction, these machines seem to be a sole way to TeV scale in lepton-hadron collisison at constituent level. An essential advantage of the linac-ring type lepton-hadron colliders is the possibility of the construction of gamma-p, gamma-A and FELgamma-A colliders based on them. Today, eRHIC, THERA (TESLA on HERA)and Linac*LHC can be considered as realistic candidates for future lepton-hadron and photon hadron colliders. When it comes to factories, one can reach essentially higher luminosities comparing to standard ring-ring type machines. For example, L=10^34 cm^-2 s^-1 can be achieved for phi and charm-tau factories. In this presentation we briefly discuss the parameters and physics search potential of the linac-ring type machines.

physics.acc-ph↗
arXiv1999

Linac-Ring Type phi Factory for Basic and Applied Researches

In this paper, main parameters for linac-ring type collider desinged for producing $ϕ$ particles copiously are estimated and potential of this machine in particle physics researches is investigated. Moreover, parameters for free electron laser and synchrotron radiation obtained from electron linac and positron ring, respectively, are determined and applications of these radiations are summarized.

physics.acc-ph↗
arXiv1997

Linac-Ring Type Colliders: Fourth Way To TeV Scale

The present status of suggested linac-ring type ep and gamma-p colliders is reviewed. The main parameters of these machines as well as e-nucleus and gamma-nucleus colliders are considered. It is shown that sufficiently high luminosities may be achieved with a reasonable improvement of proton and electron beam parameters.

physics.acc-ph↗