Hafif HİGGS bozonlarının iki müona bozunması yoluyla CERN’deki çarpıştırıcılarda incelenmesi
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Date
2023-08-21
Authors
Çiçi, Ali
Journal Title
Journal ISSN
Volume Title
Publisher
Bursa Uludağ Üniversitesi
Abstract
İki Higgs Dubletli Model’in özel bir tipi olan Lepton-Spesifik İki Higgs Dubletli Model, hafif Higgs bozonları verebildiği için tezin teorik temellerinin üzerine kurulduğu model olarak ele alındı. ATLAS ve CMS çalışma grupları, müon çifti invaryant kütlesinin yaklaşık 28GeV olduğu bölgede Standart Model’in öngörülerinde sapma olduğunu yayımladığı yeni analizlerde gösterdi. Lepton-Spesifik İki Higgs Dubletli Model yaklaşık 28 GeV kütleye sahip, önerdiği yük-parite tek Higgs ile gözlemlenen bu sapmayı açıklamaya aday olabilir. Modelin kütle spektrumu tarandıktan sonra hafif Higgs bozonları elde edildi. Yük-parite tek Higgs 𝐴’nın (𝐴 → 𝜇±𝜇±) bozunum kanalı aracılığı ile 28 GeV müon çiftinde (𝑚𝜇𝜇 ∼ 28GeV) gözlemlenen bu sapmayı açıklayabilme ihtimali olduğu görüldü. Tezde yapılan analizin sonucunda 𝜎(𝑝 𝑝 → 𝑏𝑏𝐴 → 𝑏𝑏𝜇±𝜇±) olaylarında, tan 𝛽 ∼ 12 ve 𝑚𝐴 ∼ 28 GeV için 8TeV kütle merkezi enerjisinde 1, 5𝜎, 13 TeV kütle merkezi enerjisinde 2𝜎 kadarlık Standart Model öngörülerinden sapma olduğu ve tan 𝛽 arttıkça sapmanın değerinin azaldığı gösterildi. Son olarak, yapılan analizin CMS dedektöründe bırakacağı sinyal özellikleri incelendi. Sinyali baskılayabilecek, üst kuark çifti üretimi ve b jetleriyle birlikte lepton çifti üretimi ard alanları seçilerek CMS raporundaki sınırlandırlamaların sinyal ve ard alan üzerindeki etkisi incelendi. Yük-parite tek Higgs’in kütlesi yaklaşık 28 GeV olduğunda tezde yapılan analizde müon çifti sinyalinin CMS raporunda yapılan analizle benzer özelliklere sahip olduğu ve CMS’nin yayımladığı raporda Standart Model’in öngörülerinden gözlemlenen bu sapmanın Lepton-Spesifik İki Higgs Dubletli Model’in önerdiği yük-parite tek Higgs 𝐴tarafından sağlanabileceği gösterildi. Tez boyunca düşük tan 𝛽 ∼ 12 bölgesi incelenirken, büyük tan 𝛽 bölgesi için güncel dedektör hassasiyetin ve kütle merkezi enerjisinin yeterli olmadığı sonucuna ulaşıldı.
The Lepton-Specific Two-Higgs Doublet Model, which is a special type of the Two-Higgs Doublet Models, was considered as the model on which the theoretical basis of the thesis were built, since it can yield light Higgs bosons. The ATLAS and CMS collaborations have reported in their new published analyses that the experimental results deviate from the SM predictions in the region where the muon pair invariant mass is about 28 GeV. The Lepton-Specific Two-Higgs Doublet Model can be a candidate to explain this deviation observed with its proposed charge-parity odd Higgs with a mass about 28 GeV. After the mass spectrum of the model was calculated, light Higgs bosons were obtained. It was seen that charge-parity odd Higgs "𝐴" could explain this deviation observed in 28 GeV muon pairs (𝑚𝜇𝜇 ∼ 28 GeV) via the charge-parity odd Higgs 𝐴 muon pair decay channel (𝐴 → 𝜇±𝜇±). As a result of the analysis of 𝜎(𝑝 𝑝 → 𝑏𝑏𝐴 → 𝑏𝑏𝜇±𝜇±) events made in the thesis, it was shown that there was a deviation from the Standard Model predictions of 1, 5𝜎 at 8 TeV center of mass energy and 2𝜎 at 13 TeV center of mass energy for tan 𝛽 ∼ 12 and 𝑚𝐴 ∼ 28 GeV, and the value of the deviation decreases when tan 𝛽 increases. Finally, the signal characteristics that the analysis will leave on the CMS detector were considered. The effect of the limitations in the CMS report on the signal and the background was considered by selecting the top quark pair production and lepton pair production as backgrounds with b jets that could suppress the signal. When the mass of the charge-parity odd Higgs is about 28 GeV, the analysis performed in the thesis showed that the muon pair signal has similar properties to the analysis made in the CMS report and that deviation from the predictions of the Standard Model can be obtained by the charge-parity odd Higgs 𝐴 suggested by Lepton-Specific Two Higgs Doublet Model. While considering the low tan 𝛽 ∼ 12 region throughout the thesis, it was concluded that the current detector sensitivity and center of mass energy are not sufficient for the large tan 𝛽 region.
The Lepton-Specific Two-Higgs Doublet Model, which is a special type of the Two-Higgs Doublet Models, was considered as the model on which the theoretical basis of the thesis were built, since it can yield light Higgs bosons. The ATLAS and CMS collaborations have reported in their new published analyses that the experimental results deviate from the SM predictions in the region where the muon pair invariant mass is about 28 GeV. The Lepton-Specific Two-Higgs Doublet Model can be a candidate to explain this deviation observed with its proposed charge-parity odd Higgs with a mass about 28 GeV. After the mass spectrum of the model was calculated, light Higgs bosons were obtained. It was seen that charge-parity odd Higgs "𝐴" could explain this deviation observed in 28 GeV muon pairs (𝑚𝜇𝜇 ∼ 28 GeV) via the charge-parity odd Higgs 𝐴 muon pair decay channel (𝐴 → 𝜇±𝜇±). As a result of the analysis of 𝜎(𝑝 𝑝 → 𝑏𝑏𝐴 → 𝑏𝑏𝜇±𝜇±) events made in the thesis, it was shown that there was a deviation from the Standard Model predictions of 1, 5𝜎 at 8 TeV center of mass energy and 2𝜎 at 13 TeV center of mass energy for tan 𝛽 ∼ 12 and 𝑚𝐴 ∼ 28 GeV, and the value of the deviation decreases when tan 𝛽 increases. Finally, the signal characteristics that the analysis will leave on the CMS detector were considered. The effect of the limitations in the CMS report on the signal and the background was considered by selecting the top quark pair production and lepton pair production as backgrounds with b jets that could suppress the signal. When the mass of the charge-parity odd Higgs is about 28 GeV, the analysis performed in the thesis showed that the muon pair signal has similar properties to the analysis made in the CMS report and that deviation from the predictions of the Standard Model can be obtained by the charge-parity odd Higgs 𝐴 suggested by Lepton-Specific Two Higgs Doublet Model. While considering the low tan 𝛽 ∼ 12 region throughout the thesis, it was concluded that the current detector sensitivity and center of mass energy are not sufficient for the large tan 𝛽 region.
Description
Keywords
CERN, Dedektör, Hafif higgs, Kütle, Lepton, Olay, Simülasyon, THDM, Detector, Event, Higgs, Mass, Light, Simulation
Citation
Çiçi, A. (2023). Hafif HİGGS bozonlarının iki müona bozunması yoluyla CERN’deki çarpıştırıcılarda incelenmesi. Yayınlanmamış doktora tezi. Bursa Uludağ Üniversitesi Fen Bilimleri Enstitüsü.