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Title: Examining the identity of Yukawa with gauge couplings in supersymmetric QCD at LHC

Abstract

The identity of the quark-squark-gluino Yukawa coupling with the corresponding quark-quark-gluon QCD coupling in supersymmetric theories can be examined experimentally at the Large Hadron Collider (LHC). Extending earlier investigations of like-sign di-lepton final states, we include jets in the analysis of the minimal supersymmetric standard model, adding squark-gluino and gluino-pair production to squark-pair production. Moreover we expand the method towards model-independent analyses which cover more general scenarios. In all cases, squark decays to light charginos and neutralinos persist to play a dominant role.

Authors:
; ; ; ; ; ; ;
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
910195
Report Number(s):
FERMILAB-PUB-07-035-T
arXiv eprint number hep-ph/0703160; TRN: US0704114
DOE Contract Number:
AC02-07CH11359
Resource Type:
Journal Article
Resource Relation:
Journal Name: JHEP 0707:025,2007; Journal Volume: 07; Journal Issue: 07
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; HADRONS; PRODUCTION; QUANTUM CHROMODYNAMICS; STANDARD MODEL; Phenomenology-HEP

Citation Formats

Freitas, Ayres, /Zurich U., Skands, Peter Z., /Fermilab, Spira, M., /PSI, Villigen, Zerwas, P.M., and /DESY. Examining the identity of Yukawa with gauge couplings in supersymmetric QCD at LHC. United States: N. p., 2007. Web. doi:10.1088/1126-6708/2007/07/025.
Freitas, Ayres, /Zurich U., Skands, Peter Z., /Fermilab, Spira, M., /PSI, Villigen, Zerwas, P.M., & /DESY. Examining the identity of Yukawa with gauge couplings in supersymmetric QCD at LHC. United States. doi:10.1088/1126-6708/2007/07/025.
Freitas, Ayres, /Zurich U., Skands, Peter Z., /Fermilab, Spira, M., /PSI, Villigen, Zerwas, P.M., and /DESY. Thu . "Examining the identity of Yukawa with gauge couplings in supersymmetric QCD at LHC". United States. doi:10.1088/1126-6708/2007/07/025. https://www.osti.gov/servlets/purl/910195.
@article{osti_910195,
title = {Examining the identity of Yukawa with gauge couplings in supersymmetric QCD at LHC},
author = {Freitas, Ayres and /Zurich U. and Skands, Peter Z. and /Fermilab and Spira, M. and /PSI, Villigen and Zerwas, P.M. and /DESY},
abstractNote = {The identity of the quark-squark-gluino Yukawa coupling with the corresponding quark-quark-gluon QCD coupling in supersymmetric theories can be examined experimentally at the Large Hadron Collider (LHC). Extending earlier investigations of like-sign di-lepton final states, we include jets in the analysis of the minimal supersymmetric standard model, adding squark-gluino and gluino-pair production to squark-pair production. Moreover we expand the method towards model-independent analyses which cover more general scenarios. In all cases, squark decays to light charginos and neutralinos persist to play a dominant role.},
doi = {10.1088/1126-6708/2007/07/025},
journal = {JHEP 0707:025,2007},
number = 07,
volume = 07,
place = {United States},
year = {Thu Mar 01 00:00:00 EST 2007},
month = {Thu Mar 01 00:00:00 EST 2007}
}
  • We make a numerical study of guage and Yukawa unification in supersymmetric grand unified models and examine the quantitative implications of fermion mass [ital Ansa]$[ital iuml]---[ital tze] at the grand unified scale. Integrating the renormalization group equations with [alpha][sub 1]([ital M][sub [ital Z]]) and [alpha][sub 2]([ital M][sub [ital Z]]) as inputs, we find [alpha][sub 3]([ital M][sub [ital Z]])[congruent]0.111(0.122) for [ital M][sub SUSY]=[ital m][sub [ital t]] and [alpha][sub 3]([ital M][sub [ital Z]])[congruent]0.106(0.116) for [ital M][sub SUSY]=1 TeV at one-loop (two-loop) order. Including [ital b] and [tau] Yukawa couplings in the evolution, we find an upper limit of [ital m][sub [ital t]][approxmore » lt]200 GeV from Yukawa unification. For given [ital m][sub [ital t]][approx lt]175 GeV, there are two solutions for [beta]: one with tan[beta][gt][ital m][sub [ital t]]/[ital m][sub [ital b]], and one with sin[beta][congruent]0.78([ital m][sub [ital t]]/150 GeV). Taking a popular [ital Ansatz] for the mass matrices at the unified scale, we obtain a lower limit on the top-quark mass of [ital m][sub [ital t]][approx gt]150(115) GeV for [alpha][sub 3]([ital M][sub [ital Z]])=0.11(0.12) and an upper limit on the supersymmetry parameter tan[beta][approx lt]50 if [alpha][sub 3]([ital M][sub [ital Z]])=0.11. The evolution of the quark mixing elements is also evaluated.« less
  • The one-loop evolution of couplings in the minimal supersymmetric standard model, extended to include baryon nonconserving ([ital ];sB) operators through explicit [ital R]-parity violation, is considered keeping only [ital ];sB superpotential terms involving the maximum possible number of third generation superfields. If all retained Yukawa couplings [ital Y][sub [ital i]] are required to remain in the perturbative domain ([ital Y][sub [ital i]][lt]1) up to the scale of gauge group unification, upper bounds ensue on the magnitudes of the [ital ];sB coupling strengths at the supersymmetry-breaking scale, independent of the model of unification. They turn out to be similar to themore » corresponding fixed point values reached from a wide range of [ital Y][sub [ital i]] (including all [ital Y][sub [ital i]] greater than unity) at the unification scale. The coupled evolution of the top quark and [ital ];sB Yukawa couplings results in a reduction of the fixed point value of the former.« less
  • The consequences of assuming the third-generation Yukawa couplings are all large and comparable are studied in the context of the minimal sypersymmetric extension of the standard model. General aspects of the RG evolution of the parameters, theoretical constraints needed to ensure proper electroweak symmetry breaking, and experimental and cosmological bounds on low-energy parameters are presented. We also present complete and exact semianalytic solutions to the one-loop RG equations. Focusing on SU(5) or SO(10) unification, we analyze the relationship between the top and bottom masses and the superspectrum, and the phenomenological implications of the GUT conditions on scalar masses. Future experimentalmore » measurements of the superspectrum and of the strong coupling will distinguish between various GUT-scale scenarios. And if present experimental knowledge is to be accounted for most naturally, a particular set of predictions is singled out. {copyright} {ital 1996 The American Physical Society.}« less
  • Various lepton-flavor-violating (LFV) processes in the supersymmetric standard model with right-handed neutrino supermultiplets are investigated in detail. It is shown that large LFV rates are obtained when tan{beta} is large. In the case where the mixing matrix in the lepton sector has a similar structure as the Kobayashi-Maskawa matrix and the third-generation Yukawa coupling is as large as that of the top quark, the branching ratios can be as large as {ital B}({mu}{r_arrow}{ital e}{gamma}){approx_equal}10{sup {minus}11} and {ital B}({tau}{r_arrow}{mu}{gamma}){approx_equal}10{sup {minus}7}, which are within the reach of future experiments. If we assume a large mixing angle solution to the atmospheric neutrino problem,more » the rate for the process {tau}{r_arrow}{mu}{gamma} becomes larger. We also discuss the difference between our case and the case of the minimal SU(5) grand unified theory. {copyright} {ital 1996 The American Physical Society.}« less
  • Renormalization effects of large baryon-nonconserving Yukawa couplings {lambda}{sub ijk}{sup {double_prime}}{ovr D{sub i}D{sub j}U{sub k}} lower the right-handed squark masses keeping the left-handed squark masses virtually untouched at the lowest order. At low energy they enhance the mass splitting between left- and right-handed squarks of the same generation as well as intergenerational mass splitting among squarks, potentially detectable in future colliders or in rare decays. The predicted mass of the lightest top squark becomes lower than the experimental bound for larger ranges of parameter space than that of the baryon-conserving case, hence, further constraining the parameter space of a supersymmetric theorymore » when baryon violation is included. {copyright} {ital 1997} {ital The American Physical Society}« less