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Title: Phenomenology of TeV-scale scalar leptoquarks in the EFT

Abstract

We examine new aspects of leptoquark (LQ) phenomenology using effective field theory (EFT). We construct a complete set of leading effective operators involving SU(2) singlets scalar LQ and the Standard Model fields up to dimension six. We show that, while the renormalizable LQ-lepton-quark interaction Lagrangian can address the persistent hints for physics beyond the Standard Model in the B-decays $$\bar{B}$$ → $$D^{(*)}$$$_{τ{\bar{v}}}$$ → $$\bar{B}$$ → $$\bar{K}$$ $$\ell^{+}\ell^{-}$$ and in the measured anomalous magnetic moment of the muon, the LQ higher dimensional effective operators may lead to new interesting effects associated with lepton number violation. These include the generation of one-loop and two-loops sub-eV Majorana neutrino masses, mediation of neutrinoless $$\textbf{double-}β$$ decay and novel LQ collider signals. For the latter, we focus on third generation LQ ($$Φ_3$$) in a framework with an approximate $$Z_3$$ generation symmetry and show that one class of the dimension five LQ operators may give rise to a striking asymmetric same-charge $$Φ_3Φ_3$$ pair-production signal, which leads to low background same-sign leptons signals at the LHC. For example, with $$M_{Φ_3} ~ 1 TeV$$ and a new physics scale of $Λ ~ 5 TeV$, we expect at the 13 TeV LHC with an integrated luminosity of 300 fb -1, about 5000 positively charged $τ^+τ^+$ events via $$pp → Φ_3Φ_3 → τ^+ τ^+ + 2 · j_b$$ ($$j_b = b-jet$$), about 500 negatively charged $τ^-τ^-$ events with a signature $$pp → Φ_3Φ_3 → τ^-τ^- + 4 · j + 2 · j_b$$ ($j$ = light jet) and about 50 positively charged $ℓ^+ ℓ^+$ events via $$pp → ℓ^+ ℓ^+ + 2 · j_ b +$$ $$\not{E}_T$$ for any of the three charged leptons, $ℓ^+ ℓ^+ = e^+ e^+, μ^+ μ^+, τ^+ τ^+$. It is interesting to note that, in the LQ EFT framework, the expected same-sign lepton signals have a rate which is several times larger than the QCD LQ-mediated opposite-sign leptons signals, $$gg, {\bar{qq}} → Φ_3Φ^*_3$$ → $ℓ^+ℓ^- + X$. We also consider the same-sign charged lepton signals in the LQ EFT framework at higher energy hadron colliders such as a 27 TeV HE-LHC and a 100 TeV FCC-hh.

Authors:
 [1];  [1];  [2];  [3]
  1. Technion-Israel Inst. of Tech., Haifa (Israel). Physics Dept.
  2. Brookhaven National Lab. (BNL), Upton, NY (United States). Dept. of Physics
  3. Univ. of California, Riverside, CA (United States). Dept. of Physics
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1562168
Alternate Identifier(s):
OSTI ID: 1569539
Report Number(s):
BNL-212189-2019-JAAM
Journal ID: ISSN 2470-0010; PRVDAQ
Grant/Contract Number:  
SC0012704
Resource Type:
Published Article
Journal Name:
Physical Review D
Additional Journal Information:
Journal Volume: 100; Journal Issue: 5; Journal ID: ISSN 2470-0010
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; phenomenology; TeV; leptoquark; EFT; scalar; lepton

Citation Formats

Bar-Shalom, Shaouly, Cohen, Jonathan, Soni, Amarjit, and Wudka, Jose. Phenomenology of TeV-scale scalar leptoquarks in the EFT. United States: N. p., 2019. Web. doi:10.1103/PhysRevD.100.055020.
Bar-Shalom, Shaouly, Cohen, Jonathan, Soni, Amarjit, & Wudka, Jose. Phenomenology of TeV-scale scalar leptoquarks in the EFT. United States. doi:10.1103/PhysRevD.100.055020.
Bar-Shalom, Shaouly, Cohen, Jonathan, Soni, Amarjit, and Wudka, Jose. Sun . "Phenomenology of TeV-scale scalar leptoquarks in the EFT". United States. doi:10.1103/PhysRevD.100.055020.
@article{osti_1562168,
title = {Phenomenology of TeV-scale scalar leptoquarks in the EFT},
author = {Bar-Shalom, Shaouly and Cohen, Jonathan and Soni, Amarjit and Wudka, Jose},
abstractNote = {We examine new aspects of leptoquark (LQ) phenomenology using effective field theory (EFT). We construct a complete set of leading effective operators involving SU(2) singlets scalar LQ and the Standard Model fields up to dimension six. We show that, while the renormalizable LQ-lepton-quark interaction Lagrangian can address the persistent hints for physics beyond the Standard Model in the B-decays $\bar{B}$ → $D^{(*)}$$_{τ{\bar{v}}}$ → $\bar{B}$ → $\bar{K}$ $\ell^{+}\ell^{-}$ and in the measured anomalous magnetic moment of the muon, the LQ higher dimensional effective operators may lead to new interesting effects associated with lepton number violation. These include the generation of one-loop and two-loops sub-eV Majorana neutrino masses, mediation of neutrinoless $\textbf{double-}β$ decay and novel LQ collider signals. For the latter, we focus on third generation LQ ($Φ_3$) in a framework with an approximate $Z_3$ generation symmetry and show that one class of the dimension five LQ operators may give rise to a striking asymmetric same-charge $Φ_3Φ_3$ pair-production signal, which leads to low background same-sign leptons signals at the LHC. For example, with $M_{Φ_3} ~ 1 TeV$ and a new physics scale of $Λ ~ 5 TeV$, we expect at the 13 TeV LHC with an integrated luminosity of 300 fb-1, about 5000 positively charged $τ^+τ^+$ events via $pp → Φ_3Φ_3 → τ^+ τ^+ + 2 · j_b$ ($j_b = b-jet$), about 500 negatively charged $τ^-τ^-$ events with a signature $pp → Φ_3Φ_3 → τ^-τ^- + 4 · j + 2 · j_b$ ($j$ = light jet) and about 50 positively charged $ℓ^+ ℓ^+$ events via $pp → ℓ^+ ℓ^+ + 2 · j_ b +$ $\not{E}_T$ for any of the three charged leptons, $ℓ^+ ℓ^+ = e^+ e^+, μ^+ μ^+, τ^+ τ^+$. It is interesting to note that, in the LQ EFT framework, the expected same-sign lepton signals have a rate which is several times larger than the QCD LQ-mediated opposite-sign leptons signals, $gg, {\bar{qq}} → Φ_3Φ^*_3$ → $ℓ^+ℓ^- + X$. We also consider the same-sign charged lepton signals in the LQ EFT framework at higher energy hadron colliders such as a 27 TeV HE-LHC and a 100 TeV FCC-hh.},
doi = {10.1103/PhysRevD.100.055020},
journal = {Physical Review D},
number = 5,
volume = 100,
place = {United States},
year = {2019},
month = {9}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1103/PhysRevD.100.055020

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