Naslov
The role of the S3 GUT leptoquark in flavor universality and collider searches

Autori
Doršner, Ilja ; Fajfer, Svjetlana ; Faroughy, Darius A. ; Košnik, Nejc

Izvornik
Journal of high energy physics (1029-8479) 2017 (2017), 188; 1-31

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Leptoquarks ; Flavor Physics ; Grand Unified Theories

Sažetak
We investigate the ability of the S3 scalar leptoquark to address the recent hints of lepton universality violation in B meson decays. The S3 leptoquark with quantum numbers (3, 3, 1/3) naturally emerges in the context of an SU(5) GUT model without any conflict with the stringent limits from observed nucleon stability. Scalar leptoquark S3 with left-handed couplings to 2nd and 3rd generations of charged leptons and down-type quarks seems well-suited to address both RK(∗) and RD(∗). We quantify this suitability with numerical fits to a plethora of relevant flavor observables. The proposed SU(5) model calls for a second leptoquark state, i.e., R ̃2 with quantum numbers (3, 2, 1/6), if one is to generate gauge coupling unification and neutrino mass. We accordingly include it in our study to investigate R ̃2’s ability to offset adverse effects of S3 and thus improve a quality of numerical fits. A global fit of the leptoquark Yukawa couplings shows that large couplings of light S3 to τ leptons are preferred. We furthermore identify B → K(∗)ν ̄ν as the most sensitive channel to probe the preferred region of parameter space. Large couplings of S3 to τ leptons are finally confronted with the experimental searches for τ final states at the Large Hadron Collider. These searches comprise a study of decay products of the leptoquark pair production, as well as, and more importantly, an analysis of the high-mass ττ final states.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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