A Study on Flavor Changing Neutral Current tqγ Transitions via Photon-Photon Interactions at the FCC-µp

Abstract

In new physics research beyond the standard model, research on the decay channels of the top quark are very interesting due to its large mass and short lifetime at the electroweak interaction scale. One of the rare and almost completely suppressed decay channels of the top quark in the standard model is the flavor-changing neutral current transitions. However, these transitions are made to bepossible in effective field theory, a theory beyond the standard model. In the presented study, we focused on examining the interactions in which the top quark transforms from flavor-changing neutral current transitions into an up quark or charm quark via a photon, using effective field theory. We will carry out our analysis through the μp→μγγp→μWbq ̅p→μlv_l bq ̅p(l=e,μ ve v_l= v_e 〖,v〗_μ) and μp→μγγp→μwbq ̅p→μjj ̅bq ̅p(j=u d c s,( j) ̅=u ̅ d ̅( c) ̅ s ̅ ) processes for two different center of mass energy values of the muon proton collider FCC-µp, which is planned to be built in future. By applying the chi-square test, which is a statistical analysis method, we limited on the branching ratio of the top quark to a photon and the top quark or charm quark BR(t→qγ) at a 95% confidence level. It has been observed that the obtained results improve the current experimental results by approximately four times.

Keywords

• FCNC
• Top quark
• Photon-photon interactions
• Future circular collider
• Muon proton collider

FCC-µp ‘da Foton-Foton Etkileşmesi ile Anormal Çeşni Değiştiren Nötr Akımların tqγ Geçişleri Üzerine Bir Çalışma

Öz

Standart model ötesi yeni fizik araştırmalarında, elektro zayıf etkileşme ölçeğindeki büyük kütlesi ve kısa yaşam ömrü nedeniyle üst kuark’ın bozunma kanalları üzerine çalışmalar oldukça ilgi çekicidir. Üst kuarkın, standart modelde nadir görülen ve neredeyse tamamen bastırılmış bozunma kanallarından birisi de çeşni değiştiren nötr akım geçişleridir. Ancak, bu geçişler standart model ötesi bir teori olan etkin alan teorisinde mümkün kılınmıştır. Çalışmamızda üst kuarkın çeşni değiştiren nötr akım geçişlerinden, foton aracılığı ile bir yukarı kuark ya da cazibeli kuarka dönüştüğü etkileşmeleri etkin alan teorisi ile incelemeye odaklandık. İncelememizi gelecekte inşa edilmesi planlan müon proton çarpıştırıcısı FCC-µp’ nın iki farklı kütle merkezi enerjisi değeri için, μp→μγγp→μWbq ̅p→μlv_l bq ̅p(l=e,μ ve v_l= v_e 〖,v〗_μ) ve μwbq ̅p→μjj ̅bq ̅p(j=u d c s,( j) ̅=u ̅ d ̅( c) ̅ s ̅ ) süreçleri için gerçekleştirdik. Bir istatistiksel analiz metodu olan ki-kare testini uygulayarak % 95 güvenilirlik düzeyinde top kuarkın bir foton ve yukarı kuark yada cazibeli kuarka dallanma oranı BR(t→qγ) üzerine sınırlama getirdik. Elde edilen sonuçların güncel deneysel sonuçları yaklaşık dört kat geliştirdiği gözlemlenmiştir.

Anahtar Kelimeler

• FCNC
• Üst kuark
• Foton-foton etkileşmesi
• Gelecek dairesel çarpıştırıcı
• Müon proton çarpıştırıcısı

Kaynakça

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