arXiv subjects

Burak Dagli

Publications and source records attributed to Burak Dagli.

9 recordsLinked to original sources

arXiv2026

Flavor Democracy Calls for Vector Like Leptons and Quarks

There are strong arguments favoring the Flavor Democracy hypothesis (or the Democratic Mass Matrix approach) within the Standard Model framework. However, the large mass of the top quark ($m_t >> m_b, m_\tau$) poses an obstacle to the functioning of Flavor Democracy in the three SM family scenario. While a fourth Standard Model generation could have provided a natural resolution, this possibility is now almost entirely excluded by precision data on Higgs boson production and decay rates. The Flavor Democracy hypothesis can be elegantly resurrected through the introduction of Vector-Like Leptons (VLLs) and Vector-Like Quarks (VLQs), which naturally accommodate the observed fermion mass hierarchies while remaining consistent with current experimental constraints. Currently, experimental searches for VLLs conducted by the ATLAS and CMS collaborations rely on a highly constrained Restricted Model. This model imposes a mass degeneracy between charged and neutral VLLs within a doublet and assumes the absence of right-handed neutrinos. Consequently, current results are valid only for the restricted model and do not cover a more realistic, general scenario. Therefore, to accurately reflect the physical reality, it is imperative to conduct a comprehensive re-evaluation that incorporates all viable decay channels.

hep-ph↗

arXiv2024

μTRISTAN and LHC/Tevatron/FCC/SppC Based Antimuon-Hadron Colliders

Recently, the construction of {μ^+}{e^-} and {μ^+}{μ^+} colliders, μTRISTAN, at KEK has been proposed. We argue that the construction of a similar {μ^+} ring tangential to LHC/Tevatron/FCC/SppC will give an opportunity to realize {μ^+}p and {μ^+}A collisions at multi-TeV scale center-of-mass energies. In this paper the main parameters of proposed colliders have been studied. It is shown that sufficiently high luminosities can be achieved for all proposals under consideration: L exceeds {10^{33} cm^{-2}s^{-1}} for {μ^+}p colliders and {10^{30} cm^{-2}s^{-1}} for {μ^+}A colliders. Certainly, proposed colliders will provide huge potential for both SM (especially QCD basics) and BSM physics searches.

hep-ph↗

arXiv2024

Muon Ring and FCC-ee / CEPC Based Antimuon-Electron Colliders

Recently, the construction of an antimuon-electron collider, μTRISTAN, at KEK has been proposed. We argue that the construction of a similar muon ring tangential to FCC-ee and CEPC will give an opportunity to realize antimuon-electron collisions at higher center-of-mass energies. Moreover, the same ring may be used later to realize energy-frontier antimuon-proton colliders based on FCC-pp and SppC. Similarly, changing of electron ring in μTRISTAN project into proton ring will give opportunity to investigate lepton-hadron collisions at ~2 TeV center-of-mass energies. In this paper the main parameters of proposed colliders have been studied. It is shown that sufficiently high luminosities can be achieved for all proposals under consideration.

physics.acc-ph↗

arXiv2024

Two options for muon-proton collider at FNAL

We discuss a possibility to construct multi-TeV scale μp collider at FNAL. Main advantage of this project is existence of two ring tunnels tangential to each other. There are two possible options, namely, muons in main injector with protons in Tevatron ring and vice versa. Two choices are considered for center-of-mass energy values: 2.57 TeV using 8 T bending magnets and 5.10 TeV with 16 T magnets. It is shown that luminosity values exceeding 1033 cm-2s-1 can be achieved. It is obvious that μ-FNAL will provide unique potential for both SM (especially QCD basics) and BSM searches, far beyond the eRHIC and LHeC capacities.

physics.acc-ph↗

arXiv2023

The incompleteness of the experimental searches for vector-like leptons at CERN

There are strong phenomenological arguments favoring the existence of vector-like leptons and quarks in nature. In spite of extensive studies conducted in search of vector-like quarks, there are only a limited number of experimental studies on vector-like leptons. Moreover, these searches do not include all possible decay modes of vector-like leptons. Therefore, the analyses done so far are incomplete. In this letter, we highlight decay channels that are not covered by different experimental analyses, with a focus on L3, ATLAS, and CMS results. We argue that experimental analyses should be redone considering these shortcomings.

hep-ex↗

arXiv2022

Comment on $μp$ and $μA$ Luminosities of Muon-Ion Collider at BNL

Luminosities of muon-proton and muon-nucleus collisions at a recently proposed muon-ion collider (MuIC) at Brookhaven National Laboratory (BNL) in the USA have been estimated using A Luminosity Optimizer for High Energy Physics (AloHEP) software keeping in mind beam-beam tune-shift values. It is shown that L$_{μp}$ = 3.6x10$^{31}$ cm$^{-2}$s$^{-1}$ and L$_{μ{\rm -Au}}$ = 2.84x10$^{27}$ cm$^{-2}$s$^{-1}$ values can be achieved at MuIC. The physics search potential of the collider is superior to HERA. However, LHeC will provide 2 orders of higher luminosities at approximately same center-of-mass (CoM) energies.

physics.acc-ph↗

arXiv2022

Why should we search for vector-like leptons?

There are two strong arguments in favor of vector-like leptons and quarks: Flavor Democracy call for them, and E6 GUT predicts existence of iso-singlet quarks and iso-doublet leptons. Vector-like quarks (VLQ) are extensively searched by ATLAS and CMS collaborations, but this is not the case for vector-like leptons (VLL), while they have actually similar status from phenomenology viewpoint. In this study we argue that vector-like leptons should be included into the new physics search programs of energy-frontier colliders. We consider production of vector-like partners of the first SM family leptons at the HL-LHC, HE-LHC, FCC, ILC, CLIC, Muon Collider, as well as, at ep and μ-p colliders. As for decays of vector-like leptons, we present branching ratios formulas to different channels for the most general case. Since there are many different production and decay channels for charged and neutral vector-like leptons, relevant studies should be done systematically. We invite the High Energy Physics community (both experimenters and phenomenologists) to actively participate in research on this topic.

hep-ph↗

arXiv2022

Main Parameters of the MC and FCC/SppC/LHC/RHIC based Muon-Nucleus Colliders

Construction of future Muon Collider (or dedicated mu-ring) tangential to nucleus colliders will give opportunity to realize mu-A collisions at multi-TeV center of mass energies at a luminosity of order of 10^29-10^30 cm^-2s^-1. Obviously, such colliders will essentially enlighten fundamentals of strong interactions from quark to nucleus levels as well as clarify QCD basics. This paper is devoted to estimation of main parameters of the FCC, SppC, HL-LHC, HE-LHC and RHIC based muon-nucleus collider proposals by the software AloHEP.

physics.acc-ph↗

arXiv2022

Review of Muon-Proton Collider Proposals: Main Parameters

Construction of future Muon Collider (or dedicated mu-ring) tangential to the energy frontier pp colliders will give opportunity to realize mu-p collisions at multi-TeV center of mass energies at a luminosity of order of $10^{33}$ cm$^{-2}$s$^{-1}$ ($10^{34}$ cm$^{-2}$s$^{-1}$). Obviously, such colliders will essentially enlarge the physics search potential of corresponding muon and hadron colliders for both the SM (especially for clarifying QCD basics) and BSM phenomena. This paper is devoted to review of main parameters of mu-p colliders proposed until now.

physics.acc-ph↗