Inhomogeneous pion condensed phase hosting topologically stable baryons

We discuss the inhomogeneous pion condensed phase within the framework of chiral perturbation theory. We show how the general expression of the condensate can be obtained solving three coupled differential equations, expressing how the pion fields are modulated in space. Upon using some simplifying assumptions, we determine an analytic solution in (3+1)-dimensions. The obtained inhomogeneous condensate is characterized by a non-vanishing topological charge, which can be identified with the baryonic number. In this way, we obtain an inhomogeneous system of pions hosting an arbitrary number of baryons at fixed position in space.

Dilaton chiral perturbation theory and applications

We review dilaton chiral perturbation theory (dChPT), the effective low-energy theory for the light sector of near-conformal, confining theories. dChPT provides a systematic expansion in both the fermion mass and the distance to the conformal window. It accounts for the pions and the light scalar, the approximate Nambu–Goldstone bosons for chiral and scale symmetry, respectively. A unique feature of dChPT is the existence of a large-mass regime in which the theory exhibits approximate hyperscaling, while the expansion nevertheless remains systematic. We discuss applications to lattice data, presenting successes as well as directions for future work.

ℳcTEQ (ℳ chiral perturbation theory-compatible deconfinement Temperature and Entanglement Entropy up to terms Quartic in curvature) and FM (Flavor Memory)

A (semiclassical) holographic computation of the deconfinement temperature at intermediate coupling from (a top-down) ℳ-theory dual of thermal QCD-like theories, has been missing in the literature. In the process of filling this gap, we demonstrate a novel UV-IR connection, (conjecture and provide evidence for) a non-renormalization beyond one loop of ℳ-chiral perturbation theory [1]-compatible deconfinement Temperature, and show equivalence with an Entanglement (as well as Wald) entropy [2] computation, up to terms Quartic in curvature (R). We demonstrate a Flavor-Memory (FM) effect in the ℳ-theory uplifts of the gravity duals, wherein the no-braner ℳ-theory uplift retains the “memory” of the flavor D7-branes of the parent type IIB dual in the sense that a specific combination of the aforementioned quartic corrections to the metric components precisely along the compact part (given by S3 as an S1-fibration over the vanishing two-cycle S2) of the non-compact four-cycle “wrapped” by the flavor D7-branes, is what determines, e.g., the Einstein-Hilbert action at O(R4). The aforementioned linear combination of 𝒪(R4) corrections to the ℳ-theory uplift [3, 4] metric, upon matching the holographic result from ℳχPT [1] with the phenomenological value of the coupling constant of one of the SU(3) NLO χPT Lagrangian of [5], is required to have a definite sign. Interestingly, in the decompactification (or “MKK → 0”) limit of the spatial circle in [1] to recover a QCD-like theory in four dimensions after integrating out the compact directions, we not only derive this, but in fact obtain the values of the relevant 𝒪(R4) metric corrections. Further, equivalence with Wald entropy for the black hole in the high-temperature ℳ-theory dual at 𝒪(R4) imposes a linear constraint on a similar linear combination of the abovementioned metric corrections. Remarkably, when evaluating the deconfinement temperature from an entanglement entropy computation in the thermal gravity dual, due to a delicate cancellation between the contributions arising from the metric corrections at 𝒪(R4) in the ℳ theory uplift along the S1-fiber and an S2 (which too involves a similar S1-fibration) resulting in a non-zero contribution only along the vanishing S2 surviving, one sees that there are consequently no corrections to Tc at quartic order in the curvature supporting the conjecture made on the basis of a semiclassical computation.

Interactions of two and three mesons including higher partial waves from lattice QCD

We study two- and three-meson systems composed either of pions or kaons at maximal isospin using Monte Carlo simulations of lattice QCD. Utilizing the stochastic LapH method, we are able to determine hundreds of two- and three-particle energy levels, in nine different momentum frames, with high precision. We fit these levels using the relativistic finite-volume formalism based on a generic effective field theory in order to determine the parameters of the two- and three-particle K-matrices. We find that the statistical precision of our spectra is sufficient to probe not only the dominant s-wave interactions, but also those in d waves. In particular, we determine for the first time a term in the three-particle K-matrix that contains two-particle d waves. We use three Nf = 2 + 1 CLS ensembles with pion masses of 200, 280, and 340 MeV. This allows us to study the chiral dependence of the scattering observables, and compare to the expectations of chiral perturbation theory.

MuCap: Muon Capture on the Proton

The singlet muon capture rate \Lambda_SΛS on the proton \mu^-\ p \to \nu_\mu~nμ−p→νμn is determined in a high precision lifetime measurement. The main apparatus consists of a new hydrogen time projection chamber as muon detector, developed by PSI, surrounded by cylindrical wire chambers and a plastic scintillator hodoscope as electron detectors. The parameter \Lambda_SΛS is evaluated as the difference between the inverse \mu\,pμp lifetime and that of the free \mu^+μ+. The result \Lambda_S^\text{MuCap} = (715.6 \pm 5.4^\text{stat} \pm 5.1^\text{sys})\,\text{s}^{-1}ΛSMuCap=(715.6±5.4stat±5.1sys)s−1 is in excellent agreement with the prediction of chiral perturbation theory \Lambda_S^{\chi\text{PT}} = (715.4 \pm 6.9)\,\text{s}^{-1}ΛSχPT=(715.4±6.9)s−1. From \Lambda_S^\text{MuCap}ΛSMuCap a recent analysis derives for the induced pseudoscalar coupling g^\text{MuCap}_p = 8.23 \pm 0.83gpMuCap=8.23±0.83 whereas \bar{g}^{\chi\text{PT}}_p = 8.25 \pm 0.25g‾pχPT=8.25±0.25.