LIGHT LEPTOQUARKS AS POSSIBLE SIGNATURE OF STRONG-ELECTROWEAK UNIFICATION

1992 ◽  
Vol 07 (07) ◽  
pp. 559-562 ◽  
Author(s):  
PAUL H. FRAMPTON
Keyword(s):  
Baryon Number ◽  
Proton Decay ◽  
Lepton Number ◽  
Grand Unification

In strong-electroweak unification, based on SU(15), with baryon number (B) and lepton number (L) conserved, bosons with B=±2/3, L=0 (diquarks), B=0, L=±2 (dileptons) and B=±1/3, L=±1 (leptoquarks) can occur at “light” (≤ TeV) scales. The discovery of light leptoquarks would be evidence as compelling as proton decay for grand unification.

THERMAL LEPTOGENESIS IN SO(10) GUT

2008 ◽  
Vol 23 (17n20) ◽  
pp. 1464-1469 ◽  
Author(s):  
XIANGDONG JI
Keyword(s):  
Thermal Equilibrium ◽  
Baryon Number ◽  
Lepton Number ◽  
Grand Unification ◽  
The Universe ◽  
Lepton Number Violating

I discuss the possibility of generating the observed baryon number in the universe through the lepton-number violating processes in a class of SO(10) grand unification theories. The key ingredient is the CP violating decay of the heavy right-handed neutrinos out of thermal equilibrium.

scholarly journals COMMON ORIGIN OF BARYON ASYMMETRY AND PROTON DECAY

2013 ◽  
Vol 28 (34) ◽  
pp. 1350159 ◽  
Author(s):  
PEI-HONG GU ◽  
UTPAL SARKAR
Keyword(s):  
Vacuum Expectation ◽  
Baryon Number ◽  
Proton Decay ◽  
Lepton Number ◽  
Double Beta Decay ◽  
Common Origin ◽  
Electroweak Phase Transition ◽  
Lepton Asymmetry ◽  
Baryon Number Violation ◽  
Number Violation

A successful baryogenesis theory requires a baryon-minus-lepton number violation if it works before the electroweak phase transition. The leading dimension-6 baryon number violating interactions conserve baryon-minus-lepton number, which dissociated baryogenesis from baryon number violation. We show that in some models, in which the baryon-minus-lepton number is violated in the proton and neutron decays, the baryogenesis and the nucleon decay could have a common origin. We extend the canonical seesaw model with an isotriplet leptoquark scalar and two isotriplet Higgs scalars and allow the Higgs triplet to have a quartic coupling with three leptoquark triplets and a cubic coupling with two Higgs doublets. The decays of the Higgs triplets can thus generate a baryon-minus-lepton asymmetry. The tiny vacuum expectation values of the Higgs triplets can naturally induce a testable proton decay even if the leptoquark is around the TeV scale. The leptoquark associated with any flavor neutrinos can mediate a neutrinoless double beta decay.

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 Search for lepton-number- and baryon-number-violating tau decays at Belle

2020 ◽  
Vol 102 (11) ◽  
Author(s):  
D. Sahoo ◽  
G. B. Mohanty ◽  
K. Trabelsi ◽  
I. Adachi ◽  
K. Adamczyk ◽  
...  
Keyword(s):  
Baryon Number ◽  
Lepton Number ◽  
Tau Decays

scholarly journals WHAT IS A MATTER PARTICLE?

2006 ◽  
Vol 15 (01) ◽  
pp. 259-272
Author(s):  
TSAN UNG CHAN
Keyword(s):  
Standard Model ◽  
Weak Interaction ◽  
Strong Interaction ◽  
Neutral Particle ◽  
Z Bosons ◽  
Baryon Number ◽  
Lepton Number ◽  
Neutral Particles ◽  
The Standard Model ◽  
The Stability

Positive baryon numbers (A>0) and positive lepton numbers (L>0) characterize matter particles while negative baryon numbers and negative lepton numbers characterize antimatter particles. Matter particles and antimatter particles belong to two distinct classes of particles. Matter neutral particles are particles characterized by both zero baryon number and zero lepton number. This third class of particles includes mesons formed by a quark and an antiquark pair (a pair of matter particle and antimatter particle) and bosons which are messengers of known interactions (photons for electromagnetism, W and Z bosons for the weak interaction, gluons for the strong interaction). The antiparticle of a matter particle belongs to the class of antimatter particles, the antiparticle of an antimatter particle belongs to the class of matter particles. The antiparticle of a matter neutral particle belongs to the same class of matter neutral particles. A truly neutral particle is a particle identical with its antiparticle; it belongs necessarily to the class of matter neutral particles. All known interactions of the Standard Model conserve baryon number and lepton number; matter cannot be created or destroyed via a reaction governed by these interactions. Conservation of baryon and lepton number parallels conservation of atoms in chemistry; the number of atoms of a particular species in the reactants must equal the number of those atoms in the products. These laws of conservation valid for interaction involving matter particles are indeed valid for any particles (matter particles characterized by positive numbers, antimatter particles characterized by negative numbers, and matter neutral particles characterized by zero). Interactions within the framework of the Standard Model which conserve both matter and charge at the microscopic level cannot explain the observed asymmetry of our Universe. The strong interaction was introduced to explain the stability of nuclei: there must exist a powerful force to compensate the electromagnetic force which tends to cause protons to fly apart. The weak interaction with laws of conservation different from electromagnetism and the strong interaction was postulated to explain beta decay. Our observed material and neutral universe would signify the existence of another interaction that did conserve charge but did not conserve matter.

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.

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