English
Related papers

Related papers: A cosmological bound on $e^+ e^-$ mass difference

200 papers

We have arrived at tight constraints on the photon charge, giving comparable bounds, one based on the dominance by dark energy at the present epoch, and the other based on the requirement that early universe nucleosynthesis not be affected…

Astrophysics · Physics 2008-02-13 C. Sivaram , Kenath Arun

We propose a modification of Einstein-Cartan gravity equations. The modified cosmology departs from the standard model of cosmology for small Hubble parameter. A characteristic Hubble scale h0, which is intrinsically related to cosmological…

General Relativity and Quantum Cosmology · Physics 2015-07-21 Wei Lu

Recent evidence appears to confirm that the ultra-high-energy primary cosmic ray spectrum consists mostly of protons. The fact that these protons can traverse large distances to reach Earth allows us to place bounds on Lorentz violations.…

High Energy Physics - Phenomenology · Physics 2008-11-26 Brett Altschul

We compute the classical and the quantum breaking of the dilatation current in the minimal Lorentz and CPT-violating quantum electrodynamics. At the classical level, scale symmetry is broken by the general mass term \bar{\psi}M\psi and the…

High Energy Physics - Theory · Physics 2023-09-28 J. S. Porto , A. R. Vieira

I develop a physical picture of dark energy (DE) based on fundamental principles and constants of quantum mechanics (QM) and general relativity (GR) theories. It derives from a conjecture of non-zero masses for nearly standard-model…

General Relativity and Quantum Cosmology · Physics 2023-02-23 Lorenzo Gallerani Resca

We use the Cottingham method to calculate the pion and kaon electromagnetic mass differences with as few model dependent inputs as possible. The constraints of chiral symmetry at low energy, QCD at high energy and experimental data in…

High Energy Physics - Phenomenology · Physics 2014-11-17 John F. Donoghue , Antonio F. Perez

Via a Bayesian likelihood analysis using 219 recent cosmic ray spectral data points we extract the anomalous part of the cosmic $e^\pm$ flux. First we show that a significant tension exists between the $e^\pm$ related and the rest of the…

High Energy Physics - Phenomenology · Physics 2017-01-04 Katie Auchettl , Csaba Balazs

The extended QED with renormalizable interactions breaking the Lorentz and CPT symmetry is considered and the phenomenological consequences of such a symmetry breaking are illuminated in view of recent discussion of large scale anisotropy…

Astrophysics · Physics 2007-05-23 A. A. Andrianov , P. Giacconi , R. Soldati

Small violation of Lorentz and CPT symmetries may emerge in models unifying gravity with other forces of nature. An extension of the standard model with all possible terms that violate Lorentz and CPT symmetries are included. Here a…

High Energy Physics - Theory · Physics 2019-03-27 P. R. A. Souza , A. F. Santos , S. C. Ulhoa , F. C. Khanna

A key question in cosmology is whether massive neutrinos exist on cosmic scales. Current cosmological observations have severely compressed the viable range for neutrino masses and even prefer phenomenologically an effective negative mass.…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-28 Deng Wang

A new U(1) gauge symmetry is the simplest extension of the Standard Model and has various theoretical and phenomenological motivations. In this paper, we study the cosmological constraint on the MeV scale dark photon. After the neutrino…

High Energy Physics - Phenomenology · Physics 2020-09-30 Masahiro Ibe , Shin Kobayashi , Yuhei Nakayama , Satoshi Shirai

We derive a bound on dark photon dark matter scenarios where the dark photon mass is generated through the Higgs mechanism, based on the requirement that symmetry breaking must occur sufficiently early in the universe. We emphasize that…

High Energy Physics - Phenomenology · Physics 2025-02-06 Naoya Kitajima , Shota Nakagawa , Fuminobu Takahashi , Wen Yin

Motivated by a recent detection of 511 keV photons from the center of our Galaxy, we calculate the spectrum of the soft gamma-ray background of the redshifted 511 keV photons from cosmological halos. Annihilation of dark matter particles…

Astrophysics · Physics 2009-11-10 Kyungjin Ahn , Eiichiro Komatsu

We investigate the impact of prior models on the upper bound of the sum of neutrino masses, $\sum m_{\nu}$. We use data from Large Scale Structure of galaxies, Cosmic Microwave Background, Type Ia SuperNovae, and Big Bang Nucleosynthesis.…

We describe the role of CP violation in the generation of the baryon asymmetry of the Universe, in the framework of baryogenesis through leptogenesis, with emphasis on the possible relationship between CP violation at low energies and that…

High Energy Physics - Phenomenology · Physics 2007-05-23 Gustavo C. Branco

We calculate the width difference of the scalar electron decay, $\Gamma(\tilde e_L \to e_L\omega) - \Gamma({\bar{\tilde e}}_L \to \bar e_L\omega)$ in the softly broken supersymmetrized standard model. The CP asymmetry is assumed to arise…

High Energy Physics - Phenomenology · Physics 2009-09-01 Fred J. Browning , Darwin Chang , Wai-Yee Keung

We discuss the Higgs mass and cosmological constant in the context of an emergent Standard Model, where the gauge symmetries "dissolve" in the extreme ultraviolet. In this scenario the cosmological constant scale is suppressed by power of…

High Energy Physics - Phenomenology · Physics 2020-08-26 Steven D. Bass , Janina Krzysiak

We summarize and explain the current status of time variations of the electron mass in cosmology, showing that such variations allow for significant easing of the Hubble tension, from the current $\sim5\sigma$ significance, down to between…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-03 Nils Schöneberg , Léo Vacher

Forward-backward asymmetry in the process $e^+ e^- \rightarrow \gamma Z$ is proposed as a test for $CP$--violating anomalous $\gamma \gamma Z$ and $ \gamma Z Z$ couplings. Longitudinally polarized electron beams may be used to disentangle…

High Energy Physics - Phenomenology · Physics 2010-11-01 Debajyoti Choudhury , Saurabh D. Rindani

We show that non-zero masses for a spin-1 graviton (called graviphoton) leads to considerable gravitomagnetic fields around rotating mass densities, which are not observed. The solution to the problem is found by an equivalent graviphoton…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Tajmar , C. J. de Matos