scholarly journals Proton decay in supersymmetric SU(4)c × SU(2)L × SU(2)R

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
George Lazarides ◽  
Mansoor Ur Rehman ◽  
Qaisar Shafi
Keyword(s):  
Essential Role ◽  
Baryon Number ◽  
Proton Decay ◽  
Unified Theory ◽  
Grand Unified Theory ◽  
Decay Modes ◽  
Proposed Model ◽  
Hybrid Inflation ◽  
Gut Scale ◽  
Chiral Superfields

Abstract We discuss proton decay in a recently proposed model of supersymmetric hybrid inflation based on the gauge symmetry SU(4)c× SU(2)L× SU(2)R. A U(1) R symmetry plays an essential role in realizing inflation as well as in eliminating some undesirable baryon number violating operators. Proton decay is primarily mediated by a variety of color triplets from chiral superfields, and it lies in the observable range for a range of intermediate scale masses for the triplets. The decay modes include p → e+(μ+) + π0, $$ p\to \overline{\nu}+{\pi}^{+} $$ p → ν ¯ + π + , p → K0 + e+(μ+), and $$ p\to {K}^{+}+\overline{\nu} $$ p → K + + ν ¯ , with a lifetime estimate of order 1034–1036 yrs and accessible at Hyper-Kamiokande and future upgrades. The unification at the Grand Unified Theory (GUT) scale MGUT (∼ 1016 GeV) of the Minimal Supersymmetric Standard Model (MSSM) gauge couplings is briefly discussed.

scholarly journals GRAND UNIFICATION WITHOUT HIGGS BOSONS

2012 ◽  
Vol 13 ◽  
pp. 20-27
Author(s):  
STEPHEN M. BARR ◽  
XAVIER CALMET
Keyword(s):  
Fixed Point ◽  
Weak Interactions ◽  
W Bosons ◽  
Gauge Coupling ◽  
Baryon Number ◽  
Higgs Bosons ◽  
Unified Theory ◽  
Grand Unified Theory ◽  
Grand Unified Theories ◽  
Unified Theories

We discuss how a model for the electroweak interactions without a Higgs could be embedded into a grand unified theory. The requirement of a non-trivial fixed point in the SU(2) sector of the weak interactions together with the requirement of the numerical unification of the gauge couplings leads to a prediction for the value of the SU(2) gauge coupling in the fixed point regime. The fixed point regime must be in the TeV region to solve the unitarity problem in the elastic scattering of W bosons. We find that the unification scale is at about 1014 GeV. Viable grand unified theories must thus conserve baryon number. We discuss how to build such a model without using Higgs bosons.

scholarly journals Moderately suppressed dimension-five proton decay in a flipped SU(5) model

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Naoyuki Haba ◽  
Toshifumi Yamada
Keyword(s):  
Mass Term ◽  
Proton Decay ◽  
Model Structure ◽  
Ckm Matrix ◽  
Decay Modes ◽  
Yukawa Couplings ◽  
Higher Dimensional ◽  
Gut Scale ◽  
Higgs Fields ◽  
Current Bound

Abstract We study colored Higgsino-mediated proton decay (dimension-five proton decay) in a model based on the flipped SU(5) GUT. In the model, the GUT-breaking 10, $$ \overline{\mathbf{10}} $$ 10 ¯ fields have a GUT-scale mass term and gain VEVs through higher-dimensional operators, which induces an effective mass term between the color triplets in the 5, $$ \overline{\mathbf{5}} $$ 5 ¯ Higgs fields that is not much smaller than the GUT scale. This model structure gives rise to observable dimension-five proton decay, and at the same time achieves moderate suppression on dimension-five proton decay that softens the tension with the current bound on Γ(p → K+$$ \overline{\nu} $$ ν ¯ ). We investigate the flavor dependence of the Wilson coefficients of the operators relevant to dimension-five proton decay, by relating them with diagonalized Yukawa couplings and CKM matrix components in MSSM, utilizing the fact that the GUT Yukawa couplings are in one-to-one correspondence with the MSSM Yukawa couplings in flipped models. Then we numerically evaluate the Wilson coefficients, and predict the distributions of the ratios of the partial widths of various proton decay modes.

PROTON DECAY IN SO(10) SUPERSYMMETRIC GRAND UNIFIED THEORIES

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 846-848
Author(s):  
RODOVAN DERMÍŠEK
Keyword(s):  
Parameter Space ◽  
Proton Decay ◽  
Low Energy ◽  
Unified Theory ◽  
Grand Unified Theory ◽  
Family Symmetry ◽  
Energy Data ◽  
Grand Unified Theories ◽  
Unified Theories ◽  
Proton Lifetime

We calculate the proton lifetime in a SO(10) supersymmetric grand unified theory [SUSY GUT] with U(2) family symmetry. This model fits the low energy data, including the recent data for neutrino oscillations. We discuss the predictions of this model for the proton lifetime in light of recent SuperKamiokande results which significantly constrain the SUSY parameter space of the model.

scholarly journals Grand unified theory with a stable proton

2018 ◽  
Vol 33 (31) ◽  
pp. 1844013 ◽  
Author(s):  
Bartosz Fornal ◽  
Benjamín Grinstein
Keyword(s):  
Beyond Standard Model ◽  
Standard Model ◽  
Gauge Coupling ◽  
Proton Decay ◽  
Unified Theory ◽  
Grand Unified Theory ◽  
New Particles

We demonstrate that a phenomenologically viable four-dimensional grand unified theory with no proton decay can be constructed. This is done in the framework of the minimal nonsupersymmetric SU(5) GUT by introducing new representations and separating the physical quark and lepton fields into different multiplets. In such a theory all beyond Standard Model particles are naturally heavy, but one can tune the parameters of the model such that gauge coupling unification is achieved and some of the new particles are at the TeV scale and accessible at the LHC.

scholarly journals Light-cone sum rules for proton decay

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Ulrich Haisch ◽  
Amando Hala
Keyword(s):  
Lattice Qcd ◽  
Light Cone ◽  
Sum Rules ◽  
State Of The Art ◽  
Form Factors ◽  
Baryon Number ◽  
Proton Decay ◽  
Matrix Elements ◽  
Decay Channels ◽  
Systematic Uncertainties

Abstract We estimate the form factors that parametrise the hadronic matrix elements of proton-to-pion transitions with the help of light-cone sum rules. These form factors are relevant for semi-leptonic proton decay channels induced by baryon-number violating dimension-six operators, as typically studied in the context of grand unified theories. We calculate the form factors in a kinematical regime where the momentum transfer from the proton to the pion is space-like and extrapolate our final results to the regime that is relevant for proton decay. In this way, we obtain estimates for the form factors that show agreement with the state-of-the-art calculations in lattice QCD, if systematic uncertainties are taken into account. Our work is a first step towards calculating more involved proton decay channels where lattice QCD results are not available at present.

scholarly journals Observable proton decay in flipped SU(5)

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Maria Mehmood ◽  
Mansoor Ur Rehman ◽  
Qaisar Shafi
Keyword(s):  
Neutrino Mass ◽  
Gauge Coupling ◽  
Proton Decay ◽  
Type I ◽  
Mass Model ◽  
Intermediate Scale ◽  
Decay Channels ◽  
Proton Lifetime ◽  
Hybrid Inflation ◽  
Neutrino Mass Models

Abstract We explore proton decay in a class of realistic supersymmetric flipped SU(5) models supplemented by a U(1)R symmetry which plays an essential role in implementing hybrid inflation. Two distinct neutrino mass models, based on inverse seesaw and type I seesaw, are identified, with the latter arising from the breaking of U(1)R by nonrenormalizable superpotential terms. Depending on the neutrino mass model an appropriate set of intermediate scale color triplets from the Higgs superfields play a key role in proton decay channels that include p → (e+, μ+) π0, p → (e+, μ+) K0, p →$$ \overline{v}{\pi}^{+} $$ v ¯ π + , and p →$$ \overline{v}{K}^{+} $$ v ¯ K + . We identify regions of the parameter space that yield proton lifetime estimates which are testable at Hyper-Kamiokande and other next generation experiments. We discuss how gauge coupling unification in the presence of intermediate scale particles is realized, and a Z4 symmetry is utilized to show how such intermediate scales can arise in flipped SU(5). Finally, we compare our predictions for proton decay with previous work based on SU(5) and flipped SU(5).

Deep in the Bones Lie Memories and Hopes: A Grand Unified Theory

2021 ◽  
Vol 51 (1) ◽  
pp. 22-30
Author(s):  
Daniel P. McCarthy
Keyword(s):  
Unified Theory ◽  
Grand Unified Theory ◽  
Hagia Sophia ◽  
The Sacrifice

Christ’s bones are missing at the Holy Sepulchre; St Peter’s bones remain in his basilica; Hagia Sophia was not built on bones. The absence, presence, or lack of bones effects different emphases on memory (anamnesis) and fulfillment (eschatology). In Jerusalem we witness our future glory (eschatology) already revealed in our history (anamnesis); in Rome we recall (anamnesis) the sacrifice of martyrs whose bones remain until the general resurrection (eschatology), even while we venerate the saints in light; at Hagia Sophia liturgy itself, rather than bones, provides the context for remembering the whole Christ in the power of the Spirit. Celebrating liturgy over the bones of martyrs in Rome, while venerating their sacrifice, may have accentuated the sacrificial character of the eucharistic liturgy in the Christian west, whereas in the Christian east the eschatological glory already revealed in our history and in liturgy may have shaped the eschatological character of liturgy.

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