Flavor-dependent U(1) extension inspired by lepton, baryon and color numbers

Duong Van Loi; Phung Van Dong

doi:10.1140/epjc/s10052-023-12198-z

2024 Impact factor 4.8

Particles and Fields

Open Access

Eur. Phys. J. C (2023) 83: 1048
https://doi.org/10.1140/epjc/s10052-023-12198-z

Regular Article - Theoretical Physics

Flavor-dependent U(1) extension inspired by lepton, baryon and color numbers

Duong Van Loi^a and Phung Van Dong

Phenikaa Institute for Advanced Study and Faculty of Basic Science, Phenikaa University, Yen Nghia, Ha Dong, 100000, Hanoi, Vietnam

^a loi.duongvan@phenikaa-uni.edu.vn

Received: 27 July 2023
Accepted: 29 October 2023
Published online: 17 November 2023

Abstract

There is no reason why the gauge symmetry extension is family universal as in the standard model and the most well-motivated models, e.g. left-right symmetry and grand unification. Hence, we propose a simplest extension of the standard model – a flavor-dependent U(1) gauge symmetry – and find the new physics insight. For this aim, the U(1) charge, called X, is expressed as $X = x B + y L$ $$X=x B+y L$$ in which x and y are free parameters as functions of flavor index, e.g. for a flavor i they take $x_{i}$ $$x_i$$ and $y_{i}$ $$y_i$$ respectively, where B and L denote normal baryon and lepton numbers. Imposing a relation involved by the color number 3, i.e. $- x_{1, 2, \dots, n} = x_{n + 1, n + 2, \dots, n + m} = 3 y_{1, 2, \dots, n + m} \equiv 3 z$ $-x_{1,2,\ldots ,n}=x_{n+1,n+2,\ldots ,n+m}=3y_{1,2,\ldots ,n+m}\equiv 3z$ , for arbitrarily nonzero z, we achieve a novel U(1) theory with implied X-charge. This theory not only explains the origin of the number of observed fermion families but also offers a possible solution for both neutrino mass and dark matter, which differs from $B - L$ $$B-L$$ extension. Two typical models based on this idea are examined, yielding interesting results for flavor-changing neutral currents and particle colliders, besides those of neutrino mass and dark matter.

© The Author(s) 2023

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