Thu·Oct 7, 2021Thursday·October 7, 2021

1. 01*

   Scaling Up Machine Learning For Quantum Field Theory with Equivariant Continuous Flows

   Pim de Haan🇳🇱 · Corrado Rainone🇳🇱 · Miranda C.N. Cheng🇳🇱 · Roberto Bondesan🇳🇱

   We propose a continuous normalizing flow for sampling from the high-dimensional probability distributions of Quantum Field Theories in Physics. In contrast to the deep architectures used so far for this task, our proposal is based on a shallow design and incorporates the symmetries of the problem. We test our model on the ${\varphi }^4$ theory, showing that it systematically outperforms a realNVP baseline in sampling efficiency, with the difference between the two increasing for larger lattices. On the largest lattice we consider, of size $32\times 32$, we improve a key metric, the effective sample size, from 1% to 66% w.r.t. the realNVP baseline.

   ↳ cs.LGcond-mat.stat-mechhep-lat44 citations
2. 02*

   Generalization of Weinberg's Compositeness Relations

   Yan Li🇨🇳 · Feng-Kun Guo🇨🇳 · Jin-Yi Pang🇨🇳 · Jia-Jun Wu🇨🇳

   We generalize the time-honored Weinberg's compositeness relations by including the range corrections through considering a general form factor. In Weinberg's derivation, he considered the effective range expansion up to $\mathcal{O}(p^2)$ and made two additional approximations: neglecting the non-pole term in the Low equation; approximating the form factor by a constant. We lift the second approximation, and work out an analytic expression for the form factor. For a positive effective range, the form factor is of a single-pole form. An integral representation of the compositeness is obtained and is expected to have a smaller uncertainty than that derived from Weinberg's relations. We also establish an exact relation between the wave function of a bound state and the phase of the scattering amplitude neglecting the non-pole term. The deuteron is analyzed as an example, and the formalism can be applied to other cases where range corrections are important.

   ↳ hep-phhep-exhep-latnucl-thPRD(2022)·51 citations
3. 03*

   Towards top-down holographic composite Higgs: minimal coset from maximal supergravity

   Daniel Elander🇫🇷 · Maurizio Piai🇬🇧

   Within the context of top-down holography, we study a one-parameter family of regular background solutions of maximal gauged supergravity in seven dimensions, dimensionally reduced on a 2-torus. The dual, four-dimensional confining field theory realises the global (spontaneous as well as explicit) symmetry breaking pattern SO(5)->SO(4). We compute the complete mass spectrum for the fluctuations of the 128 bosonic degrees of freedom of the five-dimensional gravity theory, which correspond to scalar, pseudoscalar, vector, axial-vector, and tensor bound states of the dual field theory, and includes particles with exotic SO(4) quantum numbers. We confirm the existence of tachyonic instabilities near the boundaries of the parameter space. We discuss the interplay between explicit and spontaneous symmetry breaking. The SO(5)/SO(4) coset might provide a first step towards the realisation of a calculable framework and ultraviolet completion of minimal composite Higgs models, if the four pseudo-Nambu-Goldstone bosons are identified with the real components of the Higgs doublet in the standard model (SM), and a subgroup of SO(4) with the SU(2)xU(1) SM gauge group. We exhibit an example with an additional localised boundary term that mimics the effect of a weakly-coupled external sector.

   ↳ hep-thhep-lathep-phJHEP(2022)·20 citations
4. 04*

   Nonperturbative effects in the Standard Model with gauged 1-form symmetry

   Mohamed M. Anber🇬🇧 · Erich Poppitz🇨🇦

   We study the Standard Model with gauged ${\mathbb{Z}}_{N=2,3,6}^{(1)}$ subgroups of its ${\mathbb{Z}}_6^{(1)}$ 1-form global symmetry, making the gauge group $\frac{SU(3)\times SU(2)\times U(1)}{{\mathbb{Z}}_N}$. We show that, on a finite ${\mathbb{T}}^3$, there are self-dual instantons of fractional topological charge. They mediate baryon- and lepton-number violating processes. We compare their amplitudes to the ones due to the usual BPST-instantons. We find that the small hypercharge coupling suppresses the fractional-instanton contribution, unless the torus size is taken sub-Planckian, or extra matter is added above the weak scale. We also discuss these results in light of the cosmological bounds on the torus size.

   ↳ hep-thhep-lathep-phJHEP(2021)·39 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.