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Constraints On Anomalous Higgs Boson Couplings Using Production And Decay İnformation İn The Four-Lepton Final State
(ScienceDirect, 2017) Bilki, Burak; ., ve diğer
A search is performed for anomalous interactions of the recently discovered Higgs boson using matrix element techniques with the information from its decay to four leptons and from associated Higgs boson production with two quark jets in either vector boson fusion or associated production with a vector boson. The data were recorded by the CMS experiment at the LHC at a center-of-mass energy of and correspond to an integrated luminosity of . They are combined with the data collected at center-of-mass energies of 7 and , corresponding to integrated luminosities of 5.1 and , respectively. All observations are consistent with the expectations for the standard model Higgs boson.
DETERMINATION OF OCHRATOXIN A IN BABY FOODS BY ELISA AND HPLC
(AKADEMIAI KIADO RT, 2015) Hampikyan, Hamparsun; ., ve diğer
Ochratoxin A, is a well-known nephrotoxic, hepatotoxic and carcinogenic mycotoxin, produced by some species of mould genera such as Aspergillus spp. and Penicillium spp. under various environmental conditions, such as moisture and temperature. The main sources of Ochratoxin A intake for humans are cereals and cereal derived products, when they are consumed in large quantities, as in the case of breakfast cereals and cereal based baby foods principally consumed by babies. In this study, a total of 150 samples (50 infant formulas, 50 follow-on formulas, and 50 cereal based supplementary foods for infants and children) were obtained randomly from various supermarkets and pharmacies in Istanbul, and 52 out of 150 (34.7%) analysed samples were contaminated with Ochratoxin A. None of the examined baby food samples were above the Turkish Food Codex maximum limit of Ochratoxin A in baby, infant, and young children foods (0.5 ?g kg–1). These results reinforce the idea of strict and routine quality controls and good hygiene practices have to be performed in every step of production to minimize the potential risk of Ochratoxin A contamination.
The İmpact Of Pretreatment With Simvastatin On Kidney Tissue Of Rats With Acute Sepsis
(AKADEMIAI KIADO RT, 2017) Aydın, İrfan; ., ve diğer
It has been reported that changes in cytokine levels affect mitochondrial functions, levels of hypoxia-inducible factor ? (HIF-1?), and tissue damage during sepsis. We aimed to investigate the effects of simvastatin pretreatment on mitochondrial enzyme activities, and on levels of ghrelin, HIF-1?, and thiobarbituric acid reactive substances (TBARS) in kidney tissue during sepsis. Rats were separated into four groups, namely, control, lipopolysaccharides (LPS) (20 mg/kg), simvastatin (20 mg/kg), and simvastatin + LPS. We measured the levels of mitochondrial enzyme activities and TBARS in the kidney using spectrophotometry. The histological structure of the kidney sections was examined after staining with hematoxylin and eosin. Tumor necrosis factor ? (TNF-?), IL-10, HIF-1?, and ghrelin immunoreactivity were examined using proper antibodies. In tissue, TNF-? (p < 0.01) and HIF-1? (p < 0.05) levels were increased in the simvastatin + LPS and LPS groups. TBARS levels were higher in the LPS group than in the other groups (p < 0.01), but they were similar in the simvastatin + LPS and control groups (p > 0.05). Ghrelin immunoreactivity was lower in the LPS group (p < 0.05) and higher in the simvastatin + LPS group than in the LPS group (p < 0.01). We observed tubular damage in the sections of the LPS group. There were no differences in mitochondrial enzyme activities between the groups (p > 0.05). We observed that pretreatment of simvastatin caused favorable changes on ghrelin and TBARS levels in rats with sepsis.
Measurement Of Double-Differential Cross Sections For Top Quark Pair Production İn Pp Collisions At Root s=8 Tev And İmpact On Parton Distribution Functions
(Springer Link, 2017) Bilki, Burak; ., ve diğer
Normalized double-differential cross sections for top quark pair ( tt¯ ) production are measured in pp collisions at a centre-of-mass energy of 8 TeV with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 19.7 fb?1 . The measurement is performed in the dilepton e±?? final state. The tt¯ cross section is determined as a function of various pairs of observables characterizing the kinematics of the top quark and tt¯ system. The data are compared to calculations using perturbative quantum chromodynamics at next-to-leading and approximate next-to-next-to-leading orders. They are also compared to predictions of Monte Carlo event generators that complement fixed-order computations with parton showers, hadronization, and multiple-parton interactions. Overall agreement is observed with the predictions, which is improved when the latest global sets of proton parton distribution functions are used. The inclusion of the measured tt¯ cross sections in a fit of parametrized parton distribution functions is shown to have significant impact on the gluon distribution.
Measurement of the B-+/- Meson Nuclear Modification Factor in Pb-Pb Collisions at root s(NN)=5.02 TeV
(American Physical Society Sites, 2017) Bilki, Burak; ., ve diğer
The differential production cross sections of B± mesons are measured via the exclusive decay channels B± ? J/? K± ? µ +µ ?K± as a function of transverse momentum in pp and PbPb collisions at a center-of-mass energy ? sNN = 5.02 TeV per nucleon pair with the CMS detector at the LHC. The pp (PbPb) dataset used for this analysis corresponds to an integrated luminosity of 28.0 pb?1 (351 µb ?1 ). The measurement is performed in the B± meson transverse momentum range of 7 to 50 GeV/c, in the rapidity interval |y| < 2.4. In this kinematic range, a strong suppression of the production cross section by about a factor of two is observed in the PbPb system in comparison to the expectation from pp reference data. These results are found to be roughly compatible with theoretical calculations incorporating beauty quark diffusion and energy loss in a quark-gluon plasma.
Measurement Of The Differential Cross Sections For The Associated Production Of A W Boson And Jets İn Proton-Proton Collisions At Root S=13 TeV
(American Physical Society Sites, 2017) Bilki, Burak; ., ve diğer
A measurement of the differential cross sections for a Wboson produced in association with jets in the muon decay channel is presented. The measurement is based on 13 TeV proton-proton collision data corresponding to an integrated luminosity of 2.2 fb?1 , recorded by the CMS detector at the LHC. The cross sections are reported as functions of jet multiplicity, jet transverse momentum pT, jet rapidity, the scalar pT sum of the jets, and angular correlations between the muon and each jet for different jet multiplicities. The measured cross sections are in agreement with predictions that include multileg leading-order (LO) and next-to-LO matrix element calculations interfaced with parton showers, as well as a next-to-next-to-LO calculation for the Wboson and one jet production.
Measurement of the Top Quark Mass İn The Dileptonic t(t)over-bar Decay Channel Using The Mass Observables M-bl, M-T2, and M-blv in pp Collisions at Root=8 TeV
(American Physical Society Sites, 2017) Bilki, Burak; ., ve diğer
A measurement of the top quark mass (Mt) in the dileptonic tt decay channel is performed using data from proton-proton collisions at a center-of-mass energy of 8 TeV. The data was recorded by the CMS experiment at the LHC and corresponds to an integrated luminosity of 19.7 ± 0.5 fb?1 . Events are selected with two oppositely charged leptons (` = e, µ) and two jets identified as originating from b quarks. The analysis is based on three kinematic observables whose distributions are sensitive to the value of Mt . An invariant mass observable, Mb` , and a ‘stransverse mass’ observable, MT2, are employed in a simultaneous fit to determine the value of Mt and an overall jet energy scale factor (JSF). A complementary approach is used to construct an invariant mass observable, Mb`? , that is combined with MT2 to measure Mt . The shapes of the observables, along with their evolutions in Mt and JSF, are modeled by a nonparametric Gaussian process regression technique. The sensitivity of the observables to the value of Mt is investigated using a Fisher information density method. The top quark mass is measured to be 172.22 ± 0.18 (stat) +0.89 ?0.93 (syst) GeV.
Measurement Of The Triple-Differential Dijet Cross Section İn Proton-Proton Collisions At Root s=8 TeV And Constraints On Parton Distribution Functions
(Springer Link, 2017) Bilki, Burak; ., ve diğer
A measurement is presented of the triple-differential dijet cross section at a centre-of-mass energy of 8 TeV using 19.7 fb-1 of data collected with the CMS detector in proton-proton collisions at the LHC. The cross section is measured as a function of the average transverse momentum, half the rapidity separation, and the boost of the two leading jets in the event. The cross section is corrected for detector effects and compared to calculations in perturbative quantum chromodynamics at next-to-leading order accuracy, complemented with electroweak and nonperturbative corrections. New constraints on parton distribution functions are obtained and the inferred value of the strong coupling constant is ?S(MZ)=0.1199±0.0015(exp)+0.0031?0.0020(theo) , where MZ is the mass of the Z boson.
Measurement Of Vector Boson Scattering And Constraints On Anomalous Quartic Couplings From Events With Four Leptons And Two Jets İn Proton-Proton Collisions At Root S=13 TeV
(ScienceDirect, 2017) Bilki, Burak; ., ve diğer
A measurement of vector boson scattering and constraints on anomalous quartic gauge couplings from events with two Z bosons and two jets are presented. The analysis is based on a data sample of proton–proton collisions at collected with the CMS detector and corresponding to an integrated luminosity of 35.9. The search is performed in the fully leptonic final state , where or ?. The electroweak production of two Z bosons in association with two jets is measured with an observed (expected) significance of 2.7 (1.6) standard deviations. A fiducial cross section for the electroweak production is measured to be , which is consistent with the standard model prediction. Limits on anomalous quartic gauge couplings are determined in terms of the effective field theory operators T0, T1, T2, T8, and T9. This is the first measurement of vector boson scattering in the channel at the LHC.
Measurements Of The pp -> W Gamma Gamma and pp -> Z Gamma Gamma Cross Sections and Limits On Anomalous Quartic Gauge Couplings at Root S=8 TeV
(Springer Link, 2017) Bilki, Burak; ., ve diğer
Measurements are presented of W?? and Z?? production in proton-proton collisions. Fiducial cross sections are reported based on a data sample corresponding to an integrated luminosity of 19.4 fb?1 collected with the CMS detector at a center-of-mass energy of 8 TeV. Signal is identified through the W ? `? and Z ? `` decay modes, where ` is a muon or an electron. The production of W?? and Z??, measured with significances of 2.6 and 5.9 standard deviations, respectively, is consistent with standard model predictions. In addition, limits on anomalous quartic gauge couplings in W?? production are determined in the context of a dimension-8 effective field theory.
Methodology For Analysis And Reporting Patterns Of Failure İn The Era Of IMRT: Head And Neck Cancer Applications
(BMC, 2016) Koçak Uzel, Esengül; ., ve diğer
Background: The aim of this study is to develop a methodology to standardize the analysis and reporting of the patterns of loco-regional failure after IMRT of head and neck cancer. Material and Methods: Twenty-one patients with evidence of local and/or regional failure following IMRT for head-and-neck cancer were retrospectively reviewed under approved IRB protocol. Manually delineated recurrent gross disease (rGTV) on the diagnostic CT documenting recurrence (rCT) was co-registered with the original planning CT (pCT) using both deformable (DIR) and rigid (RIR) image registration software. Subsequently, mapped rGTVs were compared relative to original planning target volumes (TVs) and dose using a centroid-based approaches. Failures were then classified into five types based on combined spatial and dosimetric criteria; A (central high dose), B (peripheral high dose), C (central elective dose), D (peripheral elective dose), and E (extraneous dose). Results: A total of 26 recurrences were identified. Using DIR, recurrences were assigned to more central TVs compared to RIR as detected using the spatial centroid-based method (p = 0.0002). rGTVs mapped using DIR had statistically significant higher mean doses when compared to rGTVs mapped rigidly (mean dose 70 vs. 69 Gy, p = 0. 03). According to the proposed classification 22 out of 26 failures were of type A (central high dose) as assessed by DIR method compared to 18 out of 26 for the RIR because of the tendencey of RIR to assign failures more peripherally. Conclusions: RIR tends to assigns failures more peripherally. DIR-based methods showed that the vast majority of failures originated in the high dose target volumes and received full prescribed doses suggesting biological rather than technology-related causes of failure. Validated DIR-based registration is recommended for accurate failure characterization and a novel typology-indicative taxonomy is recommended for failure reporting in the IMRT era.
Observation of Top Quark Production in Proton-Nucleus Collisions
(American Physical Society Sites, 2017) Bilki, Burak; ., ve diğer
The first observation of top quark production in proton-nucleus collisions is reported using proton-lead data collected by the CMS experiment at the CERN LHC at a nucleon-nucleon center-of-mass energy of ? sNN = 8.16 TeV. The measurement is performed using events with exactly one isolated electron or muon candidate and at least four jets. The data sample corresponds to an integrated luminosity of 174 nb?1 . The significance of the tt signal against the background-only hypothesis is above five standard deviations. The measured cross section is ?tt = 45 ± 8 nb, consistent with predictions from perturbative quantum chromodynamics.
Principal-Component Analysis Of Two-Particle Azimuthal Correlations İn PbPb And Ppb Collisions At CMS
(American Physical Society Sites, 2017) Bilki, Burak; ., ve diğer
For the first time a principle-component analysis is used to separate out different orthogonal modes of the two-particle correlation matrix from heavy ion collisions. The analysis uses data from ? sNN = 2.76 TeV PbPb and ? sNN = 5.02 TeV pPb collisions collected by the CMS experiment at the LHC. Two-particle azimuthal correlations have been extensively used to study hydrodynamic flow in heavy ion collisions. Recently it has been shown that the expected factorization of two-particle results into a product of the constituent single-particle anisotropies is broken. The new information provided by these modes may shed light on the breakdown of flow factorization in heavy ion collisions. The first two modes (“leading” and “subleading”) of two-particle correlations are presented for elliptical and triangular anisotropies in PbPb and pPb collisions as a function of pT over a wide range of event activity. The leading mode is found to be essentially equivalent to the anisotropy harmonic previously extracted from two-particle correlation methods. The subleading mode represents a new experimental observable and is shown to account for a large fraction of the factorization breaking recently observed at high transverse momentum. The principle-component analysis technique has also been applied to multiplicity fluctuations. These also show a subleading mode. The connection of these new results to previous studies of factorization is discussed.
Search for a Heavy Composite Majorana Neutrino in the Final State With Two Leptons and Two Quarks at Root s=13 TeV
(Springer Link, 2017) Bilki, Burak; ., ve diğer
A search for physics beyond the standard model in the final state with two sameflavour leptons (electrons or muons) and two quarks produced in proton-proton collisions at ? s = 13 TeV is presented. The data were recorded by the CMS experiment at the CERN LHC and correspond to an integrated luminosity of 2.3 fb?1 . The observed data are in good agreement with the standard model background prediction. The results of the measurement are interpreted in the framework of a recently proposed model in which a heavy Majorana neutrino, N` , stems from a composite-fermion scenario. Exclusion limits are set for the first time on the mass of the heavy composite Majorana neutrino, mN` , and the compositeness scale ?. For the case mN` = ?, the existence of Ne (Nµ) is excluded for masses up to 4.60 (4.70) TeV at 95% confidence level
Search For A Light Pseudoscalar Higgs Boson Produced İn Association With Bottom Quarks İn Pp Collisions At Root S=8 TeV
(Springer Link, 2017) Bilki, Burak; ., ve diğer
A search for a light pseudoscalar Higgs boson (A) produced in association with bottom quarks and decaying into a muon pair is reported. The search uses 19.7 fb?1 of proton-proton collisions at a center-of-mass energy of 8 TeV, collected by the CMS experiment. No signal is observed in the dimuon mass range from 25 to 60 GeV. Upper limits on the cross section times branching fraction, ?(pp?bb¯¯¯A)B(A???) , are set.
Search For Associated Production Of Dark Matter With A Higgs Boson Decaying To B(B)Over-Bar Or Gamma Gamma At Root S=13 TeV
(Springer Link, 2017) Bilki, Burak; ., ve diğer
A search for dark matter is performed looking for events with large missing transverse momentum and a Higgs boson decaying either to a pair of bottom quarks or to a pair of photons. The data from proton-proton collisions at a center-of-mass energy of 13 TeV, collected in 2015 with the CMS detector at the LHC, correspond to an integrated luminosity of 2.3 fb?1 . Results are interpreted in the context of a Z0 -twoHiggs-doublet model, where the gauge symmetry of the standard model is extended by a U(1)Z0 group, with a new massive Z0 gauge boson, and the Higgs sector is extended with four additional Higgs bosons. In this model, a high-mass resonance Z0 decays into a pseudoscalar boson A and a light SM-like scalar Higgs boson, and the A decays to a pair of dark matter particles. No significant excesses are observed over the background prediction. Combining results from the two decay channels yields exclusion limits in the signal cross section in the mZ0- mA phase space. For example, the observed data exclude the Z0 mass range from 600 to 1860 GeV, for Z0 coupling strength gZ0 = 0.8, the coupling of A with dark matter particles g? = 1, the ratio of the vacuum expectation values tan ? = 1, and mA = 300 GeV. The results of this analysis are valid for any dark matter particle mass below 100 GeV.
Search for Charged Higgs Bosons Produced via Vector Boson Fusion and Decaying into a Pair of W and Z Bosons Using pp Collisions at root s=13 TeV
(American Physical Society Sites, 2017) Bilki, Burak; ., ve diğer
A search for charged Higgs bosons produced via vector boson fusion and decaying into W and Z bosons using proton-proton collisions at ? s = 13 ? ? TeV is presented. The data sample corresponds to an integrated luminosity of 15.2 ? ? fb ? 1 collected with the CMS detector in 2015 and 2016. The event selection requires three leptons (electrons or muons), two jets with large pseudorapidity separation and high dijet mass, and missing transverse momentum. The observation agrees with the standard model prediction. Limits on the vector boson fusion production cross section times branching fraction for new charged physical states are reported as a function of mass from 200 to 2000 GeV and interpreted in the context of Higgs triplet models.
Search For Dark Matter Produced İn Association With Heavy-Flavor Quark Pairs İn Proton-Proton Collisions At Root S=13 TeV
(Springer Link, 2017) Bilki, Burak; ., ve diğer
A search is presented for an excess of events with heavy-flavor quark pairs (tt and bb) and a large imbalance in transverse momentum in data from proton–proton collisions at a center-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 2.2 fb?1 collected with the CMS detector at the CERN LHC. No deviations are observed with respect to standard model predictions. The results are used in the first interpretation of dark matter production in tt and bb final states in a simplified model. This analysis is also the first to perform a statistical combination of searches for dark matter produced with different heavy-flavor final states. The combination provides exclusions that are stronger than those achieved with individual heavy-flavor final states
Search For Direct Production Of Super Symmetric Partners Of The Top Quark İn The All-Jets Final State İn Proton-Proton Collisions At Root S=13 TeV
(Springer Link, 2017) Bilki, Burak; ., ve diğer
A search for direct production of top squark pairs in events with jets and large transverse momentum imbalance is presented. The data are based on proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector in 2016 at the CERN LHC, and correspond to an integrated luminosity of 35.9 fb?1 . The search considers a variety of R-parity conserving supersymmetric models, including ones for which the top squark and neutralino masses are nearly degenerate. Specialized jet reconstruction tools are developed to exploit the unique characteristics of the signal topologies. With no significant excess of events observed above the standard model expectations, upper limits are set on the direct top squark pair production cross section in the context of simplified supersymmetric models for various decay hypotheses. Models with larger differences in mass between the top squark and neutralino are probed for masses up to 1040 and 500 GeV, respectively, whereas models with a more compressed mass hierarchy are probed up to 660 and 610 GeV, respectively. The smallest mass difference probed is for masses near to 550 and 540 GeV, respectively
Search For Electroweak Production Of Charginos And Neutralinos İn WH Events İn Proton-Proton Collisions At Root S=13 TeV
(Springer Link, 2017) Bilki, Burak; ., ve diğer
Results are reported from a search for physics beyond the standard model in proton-proton collision events with a charged lepton (electron or muon), two jets identified as originating from a bottom quark decay, and significant imbalance in the transverse momentum. The search was performed using a data sample corresponding to 35.9 fb?1, collected by the CMS experiment in 2016 at s?=13 TeV. Events with this signature can arise, for example, from the electroweak production of gauginos, which are predicted in models based on supersymmetry. The event yields observed in data are consistent with the estimated standard model backgrounds. Limits are obtained on the cross sections for chargino-neutralino (?~±1?~02) production in a simplified model of supersymmetry with the decays ?±1?W±?~01and?~02?H?01 . Values of m?~±1 between 220 and 490 GeV are excluded at 95% confidence level by this search when the ?~01 is massless, and values of m?~01 are 1 excluded up to 110 GeV for m?~±1?450 GeV. Open image in new window