337 research outputs found

    Determination of the charged hadron fractions for different jet triggers in cms experiment.

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    TEZ11461Tez (YĂŒksek Lisans) -- Çukurova Üniversitesi, Adana, 2019.Kaynakça (s. 63-64) var.xvi, 65 s. : res. (bzs. rnk.), tablo ; 29 cm.Jetler, yĂŒksek enerji deneylerinde ortaya çıkan kuark ve gluonların deneysel imzalarıdır ve BHÇ gibi çarpÄ±ĆŸtırıcılarda bĂŒyĂŒk bir tesir kesiti ile ĂŒretilirler. Jetler birçok parçacık fiziği çalÄ±ĆŸmalarının araƟtırılmasında önemli bir rol oynadıklarından belirlenip yeniden yapılandırılması oldukça önemlidir. Bu tez çalÄ±ĆŸmasında CMS deneyi 2016 çarpÄ±ĆŸma ve Monte Carlo (MC) verilerinin kalite kontrol çalÄ±ĆŸmaları sırasında yĂŒklĂŒ hadron oranında beklenmedik bir ek katkı (ikinci bir tepe noktası) gözlenmiƟtir. Bu katkının araƟtırılması için farklı jet tetikleyicilerinde yĂŒklĂŒ hadron oranı belirlenmiƟtir. ÇalÄ±ĆŸma sırasında temel fizik objesi olarak PF jetleri seçilmiƟtir. Bu jetler AK4 olarak adlandırılan ve koni yarıçapı R = 0.4 olan anti-kT algoritması ile yeniden yapılandırılmÄ±ĆŸtır. Aynı çarpÄ±ĆŸma verisinden gelen yeniden oluƟturulmuƟ jetlerdeki pile-up katkısını azaltmak için CHS tekniği kullanılmÄ±ĆŸtır. Bu tez çalÄ±ĆŸmasında yĂŒklĂŒ hadron oranında görĂŒlen ek katkının araƟtırılması için yapılan analizlerin sonuçları sunulmuƟtur.Jets are the experimental signatures of quarks and gluons that occur in high energy experiments and are produced with a large cross-section in colliders such as LHC. Since jets play an important role in explaining many particle physics studies, it is very important to determine and reconstruct them. In this thesis, during the quality control studies carried out with the 2016 collision data collected by CMS and MC data, an unexpected additional contribution (a second peak) was observed in the charged hadron energy fraction. In order to investigate this undesired contribution, charged hadron energy fraction on different jet triggers was determined. PF jets were chosen as a physics object for the study. These jets were reconstructed with the anti-kT algorithm where the cone radius R is 0.4. The CHS technique used to reduce the pile-up contribution in reconstructed jets from the same collision data. In this thesis, the results of the analysis performed to investigate the additional contribution in the charged hadron energy fraction are presented.Bu çalÄ±ĆŸma Ç.Ü. Bilimsel AraƟtırma Projeleri Birimi tarafından desteklenmiƟtir. Proje No: FYL201810140

    Measurement of the double-differential inclusive jet cross section in proton-proton collisions at s\sqrt{s} = 5.02 TeV

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    International audienceThe inclusive jet cross section is measured as a function of jet transverse momentum pTp_\mathrm{T} and rapidity yy. The measurement is performed using proton-proton collision data at s\sqrt{s} = 5.02 TeV, recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 27.4 pb−1^{-1}. The jets are reconstructed with the anti-kTk_\mathrm{T} algorithm using a distance parameter of RR = 0.4, within the rapidity interval ∣y∣\lvert y\rvert<\lt 2, and across the kinematic range 0.06 <\ltpTp_\mathrm{T}<\lt 1 TeV. The jet cross section is unfolded from detector to particle level using the determined jet response and resolution. The results are compared to predictions of perturbative quantum chromodynamics, calculated at both next-to-leading order and next-to-next-to-leading order. The predictions are corrected for nonperturbative effects, and presented for a variety of parton distribution functions and choices of the renormalization/factorization scales and the strong coupling αS\alpha_\mathrm{S}

    Observation of four top quark production in proton-proton collisions at s\sqrt{s} = 13 TeV