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Title: Estimating scalar-leptoquark masses from the muon anomalous magnetic moment within the four-color symmetry model

Abstract

The contributions to the muon anomalous magnetic moment from the doublets of scalar leptoquarks having a four-color origin are studied. It is shown that experimental data on the muon anomalous magnetic moment are compatible with the existence of relatively light scalar leptoquarks (of mass about 1 TeV or below)

Authors:
 [1]
  1. Yaroslavl State University (Russian Federation), E-mail: povarov@univ.uniyar.ac.ru
Publication Date:
OSTI Identifier:
21076063
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Atomic Nuclei; Journal Volume: 69; Journal Issue: 5; Other Information: DOI: 10.1134/S1063778806050115; Copyright (c) 2006 Nauka/Interperiodica; Article Copyright (c) 2006 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; COLOR MODEL; GEV RANGE; LEPTONS; MAGNETIC MOMENTS; MASS; MUONS; SCALARS; SYMMETRY

Citation Formats

Povarov, A. V.. Estimating scalar-leptoquark masses from the muon anomalous magnetic moment within the four-color symmetry model. United States: N. p., 2006. Web. doi:10.1134/S1063778806050115.
Povarov, A. V.. Estimating scalar-leptoquark masses from the muon anomalous magnetic moment within the four-color symmetry model. United States. doi:10.1134/S1063778806050115.
Povarov, A. V.. Mon . "Estimating scalar-leptoquark masses from the muon anomalous magnetic moment within the four-color symmetry model". United States. doi:10.1134/S1063778806050115.
@article{osti_21076063,
title = {Estimating scalar-leptoquark masses from the muon anomalous magnetic moment within the four-color symmetry model},
author = {Povarov, A. V.},
abstractNote = {The contributions to the muon anomalous magnetic moment from the doublets of scalar leptoquarks having a four-color origin are studied. It is shown that experimental data on the muon anomalous magnetic moment are compatible with the existence of relatively light scalar leptoquarks (of mass about 1 TeV or below)},
doi = {10.1134/S1063778806050115},
journal = {Physics of Atomic Nuclei},
number = 5,
volume = 69,
place = {United States},
year = {Mon May 15 00:00:00 EDT 2006},
month = {Mon May 15 00:00:00 EDT 2006}
}
  • Extensions of the supersymmetric standard model to SU(2){sub {ital L}}{times}U(1){sub {ital I}3}{ital R}{times}U(1){sub {ital B}{minus}{ital L}} and to SU(2){sub {ital L}}{times}SU(2){sub {ital R}}{times}U(1){sub {ital B}{minus}{ital L}} with Higgs triplets are considered. Calculations of all possible contributions to the anomalous magnetic moment of the muon are made and the resulting constraints on the masses of supersymmetric partners are examined in detail.
  • The rare t-quark decays t {sup {yields}} cl{sub j}{sup +}l{sub k}{sup -} and t {sup {yields}} cv-tilde {sub j}k{sub k} induced by scalar-leptoquark doublets are considered within the minimal model involving four-color quark-lepton symmetry and the Higgs mechanism of quark and lepton mass splitting. The partial widths with respect to the decays being considered and the total widths {gamma}(t {sup {yields}} cl{sup +}'l{sup -}) {sigma}{sub j,k} {gamma}(t {sup {yields}} cl{sub j}{sup +}l{sub k}{sup -}) and {gamma}(t {sup {yields}} cl{sup +}'l{sup -}) {sigma}{sub j,k}{gamma}(t {sup {yields}} cv-tilde {sub j}v{sub k}) with respect to, respectively, the charged leptonic and neutrino modes aremore » calculated. It is shown that, at scalar-leptoquark masses higher than the t-quark mass (m{sub S} > m{sub t}), the branching ratios for these modes are Br(t {sup {yields}} cl{sup +}'l{sup -}) {approx} (3.5-0.4) x 10{sup -5} and Br(t {sup {yields}} cv-tilde 'v) {approx} (7.1-0.8) x 10{sup -5} at m{sub s} 180-250 GeV and an appropriate value of the leptoquark-mixing angle (sin {beta} {approx} 0.2) and can increase for m{sub S} < m{sub t} to Br(t {sup {yields}} cl{sup +}'l{sup -}) {approx} 0.03-0.002 and Br(t {sup {yields}} cl{sup +}'l{sup -}) {approx} 0.46-0.05 for the charged mode at m{sub S} = 150-170 GeV for sin {beta} {approx} 1 and sin {beta} {approx} 0.2, respectively. In the cases being considered, t-quark decays to pairs of charged leptons can be accessible to detection at LHC. In the last case, these decays could manifest themselves (for example, in dilepton events) at the Tevatron as well.« less
  • We calculate the contribution of second generation scalar leptoquarks to the anomalous magnetic moment of the muon. The coupling {lambda}{sub {phi}}{sub {ital L}} between the leptoquarks, the quarks, and the leptons is taken to be of the order of the electroweak coupling {ital g}{sub 2}. In the near future, the E-821 Collaboration at Brookhaven will reduce the experimental error on this parameter to {delta}{ital a}{sub {mu}}{sup e}{sup x}{sup p}{sup t}{much_gt}4{times}10{sup -}{sup 1}{sup 0}, an improvement of 20 over its current value. Combining this error with the current uncertainty on the hadronic contribution to {ital g}-2 we obtain a bound ofmore » {ital m}{sub {phi}}{sub {ital L}}{much_lt}88 GeV for the second generation scalar leptoquark while we get {ital m}{sub {phi}}{sub {ital L}}{much_lt}186 GeV when neglecting the hadronic uncertainty. {copyright} {ital 1995 The American Physical Society.}« less
  • We present a detailed and complete calculation of the doubly charged Higgsino contribution to the decays {mu}{r_arrow}e{gamma} and {mu}{r_arrow}3e and to the anomalous magnetic moment of the muon {Delta}a{sub {mu}} within the left-right supersymmetric model. We include the mixing of the scalar partners of the left- and right-handed leptons, and show that it leads to a strong enhancement of the decay modes in certain scenarios. We find that the contribution of the doubly charged Higgsino can be close to the known experimental values and is reachable by future experiments. {copyright} {ital 1997} {ital The American Physical Society}
  • Fermionic and weak decays of the scalar leptoquarks S = S{sub 1}{sup (+)}, S{sub 1}{sup (-)}, and S{sub m} and the scalar gluons F = F{sub 1} and F{sub 2} predicted by the minimal model involving four-color symmetry and the Higgs mechanism of quark-and lepton-mass splitting are considered. The widths and the branching ratios are calculated for these decays, and the results are analyzed versus the couplings and masses of decaying particles. It is shown that, at relatively small mass splittings {delta}m within scalar doublets ({delta}m < m{sub W}), the fermionic decays S{sub 1}{sup (+)} {sup {yields}} tl{sub j}{sup +},more » S{sub 1}{sup (-)} {sup {yields}} v{sub i}b-tilde, S{sub m} {sup {yields}} t{nu}-tilde{sub j}, F{sub 1} {sup {yields}} tb-tilde, and F{sub 2} {sup {yields}} tt-tilde, which are characterized by few-GeV widths for m{sub S}, m{sub F} < 1 TeV and decay branching ratios close to unity, are dominant, but that, for {delta}m > m{sub W}, the weak decays S {sup {yields}} S'W and F {sup {yields}} F'W compete with the above fermionic decays. In the case of m{sub S} < m{sub t}, the processes S{sub 1}{sup (+)} {sup {yields}} cl{sub j}{sup +}, S{sub 1}{sup (-)} {sup {yields}} v{sub i}b-tilde, S{sub m} {sup {yields}} bl{sub j}{sup +}, and S{sub m} {sup {yields}} c{nu}-tilde{sub j}, whose total branching ratios are Br(S{sub 1}{sup (+)} {sup {yields}} cl{sup +}) {approx} Br(S{sub 1}{sup (-)} {sup {yields}} vb-tilde) {approx} 1, Br(S{sub m} {sup {yields}} bl{sup +}) {approx} 0.9, and Br(S{sub m} {sup {yields}} c{nu}-tilde) {approx} 0.1, appear to be dominant decays of scalar leptoquarks. Searches for these decays at LHC and the Tevatron are of interest.« less