相关论文: Spacetime foam at a TeV

In light of recent results from the LHC, MEG and neutrino experiments, we revisit the issue of charged lepton flavour violation (LFV) in supersymmetric theories with massive neutrinos, where flavour-violating soft supersymmetry-breaking…

Leptogenesis, i.e. the creation of a lepton asymmetry in the early Universe, may occur through the decay of heavy singlet (right-handed) neutrinos. If we require it not to be erased by physics beyond the Standard Model at the TeV energy…

We revisit a supersymmetric string model for space-time foam, in which bosonic open-string states, such as photons, can possess quantum-gravity-induced velocity fluctuations in vacuum. We argue that the suggestion of light speed variation…

We investigate the lepton flavor violation decays, $\tau \to \mu\gamma$, $\tau \to e\gamma$ and $\mu \to e\gamma$, in the framwork of a squential fourth generation model with a heavy fourth neutrino, $\nu'$. Using the recent experimental…

We study the lepton flavor violating process, $e+ T \to \tau +T'$, at a few GeV. This process can be studied by experiments directing GeV scale electron or positron beams on internal or fixed targets. We study the effects of some low energy…

Realistic effective supergravity models have a variety of sources of lepton flavour violation (LFV) which can drastically affect the predictions relative to the scenarios usually considered in the literature based on minimal supergravity…

It has been proposed that propagation of cosmic rays at extreme-energy may be sensitive to Lorentz-violating metric fluctuations (``foam''). We investigate the changes in interaction thresholds for cosmic-rays and gamma-rays interacting on…

Previous studies on high-energy gamma-ray burst neutrinos from IceCube suggest a neutrino speed variation at the Lorentz violation~(LV) scale of $\sim 6.4\times 10^{17}$~GeV, with opposite velocity variances between neutrinos and…

It has been proposed recently that the scale of quantum gravity (``the string scale'') can be $M_S \sim$ few TeV with $n \geq 2$ extra dimensions of size $R \stackrel{<}{\sim}$ mm so that, at distances greater than $R$, Newtonian gravity…

In some quantum theories of gravity, deviations from the laws of relativity could be comparatively large while escaping detection to date. In the neutrino sector, precision experiments with beta decay yield new and improved constraints on…

Partial compositeness as a theory of flavor in the lepton sector is assessed. We begin presenting the first systematic analysis of neutrino mass generation in this context, and identifying the distinctive mass textures. We then update the…

We study the implications of an approximate $U(2)^5$ flavor symmetry at the TeV scale, under the assumption of new physics predominantly coupled to the third-generation fermions, focusing on the breaking of the $U(2)_\ell$ subgroup…

We discuss lepton flavor violation (LFV) in the context of SUSY breaking when the first-two generation sleptons are heavy. When the first-two generation sleptons are $\mathcal{O}(5 {\rm TeV})$ and have small mass-splittings, we find that a…

We study some phenomenological implications of models where the scale of quantum gravity effects lies much below the four-dimensional Planck scale. These models arise from M-theory vacua where either the internal space volume is large or…

In supersymmetric theories without R-parity, the gravitino can play the role of a decaying Dark Matter candidate without the problem of late NLSP decays affecting Big Bang Nucleosynthesis. In this work, we elaborate on recently discussed…

Theoretical aspects of lepton-flavor violating (LFV) processes on the supersymmetric models are reviewed. In particular, we show that, assuming the minimal supergravity scenario, the LFV interaction at the higher energy scale leads to the…

Spacetime undergoes quantum fluctuations, giving rise to spacetime foam, a.k.a. quantum foam. We discuss some properties of spacetime foam, and point out the conceptual interconnections in the physics of quantum foam, black holes, and…

Here I review the status and prospects of experimental investigations into lepton flavor violation (LFV) in charged leptons. Rare LFV processes are naturally expected to occur through loops of TeV scale particles predicted by supersymmetric…

The interactions of different particle species with the foamy space-time fluctuations expected in quantum gravity theories may not be universal, in which case different types of energetic particles may violate Lorentz invariance by varying…

We discuss violations of CPT and quantum mechanics due to interactions of neutrinos with space-time quantum foam. Neutrinoless double beta decay and oscillations of neutrinos from astrophysical sources (supernovae, active galactic nuclei)…