Naturalness

About: Naturalness is a research topic. Over the lifetime, 1305 publications have been published within this topic receiving 31737 citations.

Fine-Grained Style Control In Transformer-Based Text-To-Speech Synthesis

Abstract: In this paper, we present a novel architecture to realize fine-grained style control on the transformer-based text-to-speech synthesis (TransformerTTS). Specifically, we model the speaking style by extracting a time sequence of local style tokens (LST) from the reference speech. The existing content encoder in TransformerTTS is then replaced by our designed cross-attention blocks for fusion and alignment between content and style. As the fusion is performed along with the skip connection, our cross-attention block provides a good inductive bias to gradually infuse the phoneme representation with a given style. Additionally, we prevent the style embedding from encoding linguistic content by randomly truncating LST during training and using wav2vec 2.0 features. Experiments show that with fine-grained style control, our system performs better in terms of naturalness, intelligibility, and style transferability. Our code and samples are publicly available. ¹

Supersymmetric Naturalness Beyond MSSM

Abstract: The experiments at the Large Hadron Collider (LHC) have pushed the limits on masses of supersymmetric particles beyond the ∼TeV scale. This compromises naturalness of the simplest supersymmetric extension of the Standard Model, the minimal supersymmetric Standard Model (MSSM). In this paper we advocate that perhaps the current experimental data are actually hinting towards the physics beyond MSSM. To illustrate this, we treat the MSSM as a low-energy limit of a more fundamental yet unspecified theory at a scale Λ, and compute the fine-tuning measure Δ for generic boundary conditions with soft SUSY breaking parameters and various cut-off scales. As a general trend we observe reduction in fine-tuning together with lowering Λ. In particular, perfectly natural [Δ ≲ $$ \mathcal{O} $$ (10)] theories with a multi-TeV spectrum of supersymmetric particles that are consistent with all current observations can be obtained for Λ ∼ $$ \mathcal{O} $$ (100)TeV. The lowering of the fine-tuning for large cut-off scales can also be observed in theories exhibiting special quasi-fixed point behaviour for certain parameters. Our observations call for a more thorough exploration of possible alternative ultraviolet completions of MSSM.

Lorentz violation naturalness revisited

Abstract: We revisit here the naturalness problem of Lorentz invariance violations on a simple toy model of a scalar field coupled to a fermion field via a Yukawa interaction. We first review some well-known results concerning the low-energy percolation of Lorentz violation from high energies, presenting some details of the analysis not explicitly discussed in the literature and discussing some previously unnoticed subtleties. We then show how a separation between the scale of validity of the effective field theory and that one of Lorentz invariance violations can hinder this low-energy percolation. While such protection mechanism was previously considered in the literature, we provide here a simple illustration of how it works and of its general features. Finally, we consider a case in which dissipation is present, showing that the dissipative behaviour does not percolate generically to lower mass dimension operators albeit dispersion does. Moreover, we show that a scale separation can protect from unsuppressed low-energy percolation also in this case.

Electroweak Symmetry Breaking, Intermediate Regulators and Physics Beyond the Standard Model

Abstract: According to the long-standing received wisdom, a "small" value of the Higgs mass - as for instance implied by general unitarity constraints - is highly "unnatural" and essentially $\mbox{requires}$ new physics to be present at or near currently accessible energy scales. Following the discovery of a new, Higgslike boson at the LHC facility in 2012, but with no sign of new physics after having explored a large region of parameter space, a dilemma thus seems to present itself : either the newly discovered boson is indeed the long-sought Higgs boson of the standard model of particle physics (or some appropriate variant of that model) and the new physics at the TeV scale, supposedly required by the naturalness argument, is still waiting to be discovered, possibly by LHC-II, or the identification of the new boson as the Higgs cannot be maintained. It is shown that this apparent dilemma is in fact a false one, in that nothing in contemporary particle physics dictates that a small Higgs mass be unnatural in any way.

Neutral naturalness with bifundamental gluinos

Abstract: We study constraints on one-loop neutral naturalness at the LHC by considering gluon partners which are required to ameliorate the tuning in the Higgs mass-squared arising at two loops. This is done with a simple orbifold model of folded supersymmetry which not only contains color-neutral stops but also bifundamental gluinos that are charged under the Standard Model color group $SU(3)_C$ and a separate $SU(3)_C'$ group. The bifundamental gluinos reduce the Higgs mass tuning at two loops and maintain naturalness provided the gluinos are lighter than approximately 1.9 TeV for a 5 TeV cutoff scale. Limits from the LHC already forbid bifundamental gluinos below 1.4 TeV, and other non-colored states such as electroweakinos, $Z'$ bosons and dark sector bound states may be probed at future colliders. The search for bifundamental gluinos therefore provides a direct probe of one-loop neutral naturalness that can be fully explored at the LHC.