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In this paper, I critically assess two recent proposals for an interpretation-independent understanding of non-relativistic quantum mechanics: the overlap strategy (Fraser & Vickers, 2022) and the textbook account (Egg, 2021). My argument has three steps. I first argue that they presume a Quinean-Carnapian meta-ontological framework that yields flat, structureless ontologies. Second, such ontologies are unable to solve the problems that quantum ontologists want to solve. Finally, only structured ontologies are capable of solving the problems that quantum ontologists want to solve. But they require some dose of speculation. In the end, I defend the conservative way to do quantum ontology, which is (and must be) speculative and non-neutral. [ABSTRACT FROM AUTHOR]

The traditional approach to nuclear physics encodes phase shift information in a nucleon-nucleon (NN) potential, producing a nucleon-level interaction that captures the sub-GeV consequences of QCD. A further reduction to the nuclear scale is needed to produce an effective interaction for soft Hilbert spaces, such as those employed in the shell model. Here we describe an alternative construction of the effective interaction that is simple and quite precise, proceeding from the QCD scale directly to the nuclear scale. This eliminates the need for constructing and renormalizing the high-momentum NN potential. Instead, continuum phase shifts and mixing angles are used directly at the nuclear scale. The method exploits the analytic continuity in energy of HOBET (Harmonic-Oscillator-Based Effective Theory) to connect bound states to continuum solutions at specific energies. The procedure is systematic, cutoff independent, and convergent, yielding keV accuracy at NNLO or N3LO, depending on the channel. Lepage plots are provided.

The paper presents the methodology of effective theories as a strategy used in the process of development of modern physics to reach a final theory. We present the definition and characteristic features of an effective theory, as well as the answer to the question of whether and what kind of scenario of reaching a final theory is realized by contemporary physics. We argue that the process of development of physics in the direction of a final theory is potentially final, i.e. expressible in the conceptual schema of effective theories and as such it is convergent to a final theory. In each effective theory there are physical constants, however, whose status differs from logical constants. They have a dimension (length, energy, etc.) and are used to compare physical quantities. The structure of relevant effective theory can be interpreted in the epistemological framework of approximated truth theory. In the case study of cosmological models, the sequence of models is convergent to potentially true model. The Standard Cosmological Model is the theory of the structure and dynamics of the Universe.

Low-energy scattering is well described by the effective-range expansion. In quantum mechanics, a tower of contact interactions can generate terms in this expansion after renormalization. Scattering parameters are also encoded in the self-adjoint extension of the Hamiltonian. We briefly review this well-known result for two particles with s -wave interactions using impenetrable self-adjoint extensions, including the case of harmonically trapped two-particle states. By contrast, the one-dimensional scattering problem is surprisingly intricate. We show that the families of self-adjoint extensions correspond to a coupled system of symmetric and antisymmetric outgoing waves, which is diagonalized by an S U (2) transformation that accounts for mixing and a relative phase. This is corroborated by an effective theory computation that includes all four energy-independent contact interactions. The equivalence of various one-dimensional contact interactions is discussed and scrutinized from the perspective of renormalization. As an application, the spectrum of a general point interaction with a harmonic trap is solved in one dimension. • One-dimensional self-adjoint extensions produce coupled systems of parity waves. • Contact interaction coefficients are related to self-adjoint extension parameters. • Equivalence of contact interactions scrutinized using renormalization. • Renormalizing the delta-prime potential must include parity mixing. • Quantum scale anomaly indirectly found with self-adjoint extension in harmonic trap. [ABSTRACT FROM AUTHOR]

In the context of upcoming new physics searches at the LHC, we investigate the impact of multidimensional differential rates in typical LHC analyses. We discuss the properties of shape information, and argue that multidimensional rates bring limited information in the scope of a discovery, but can have a large impact on model discrimination. We also point out subtleties about systematic uncertainties cancellations and the Cauchy–Schwarz bound on interference terms.

A class of effective field theory called delta-theory, which improves ultraviolet divergences in quantum field theory, is considered. We focus on a scalar model with a quartic self-interaction term and construct the delta theory by applying the so-called delta prescription. We quantize the theory using field variables that diagonalize the Lagrangian, which include a standard scalar field and a ghost or negative norm state. As well known, the indefinite metric may lead to the loss of unitary of the S -matrix. We study the optical theorem and check the validity of the cutting equations for three processes at one-loop order, and found suppressed violations of unitarity in the delta coupling parameter of the order of ξ 4 . [ABSTRACT FROM AUTHOR]

We give a concise version of a recently proposed concept of fractionalization of an order parameter, thus generating a constraint through a fictitious gauge field (Chakraborty et al. 2019). We argue that this new line of approach is key to explain the longstanding mystery of the pseudo-gap phase in cuprate superconductors. For example, the fractionalization of a finite momentum, charge two state living on lattice bonds- also called Pair Density Wave, into a particle-particle and a particle-hole pair leads to the opening of a gap in the fermionic spectrum. It induces "phase-locking" between the particle-particle and particle-hole pairs. We describe the formation of the Fermi arcs in the spectrum and give an account of recent Raman spectroscopy results from a minimal microscopic model. We relate the "phase-locking" to intriguing STM experimental observations. [ABSTRACT FROM AUTHOR]

For an effective field theory in the background of an evaporating black hole with spherical symmetry, we consider non-renormalizable interactions and their relevance to physical effects. The background geometry is determined by the semi-classical Einstein equation for an uneventful horizon where the vacuum energy–momentum tensor is small for freely falling observers. Surprisingly, after Hawking radiation appears, the transition amplitude from the Unruh vacuum to certain multi-particle states grows exponentially with time for a class of higher-derivative operators after the collapsing matter enters the near-horizon region, despite the absence of large curvature invariants. Within the scrambling time, the uneventful horizon transitions towards a firewall, and eventually the effective field theory breaks down.

Decoupling of heavy quarks at low energies can be described by means of an effective theory as shown by S. Weinberg in Ref. [1]. We study the decoupling of the charm quark by lattice simulations. We simulate a model, QCD with two degenerate charm quarks. In this case the leading order term in the effective theory is a pure gauge theory. The higher order terms are proportional to inverse powers of the charm quark mass M starting at M−2. Ratios of hadronic scales are equal to their value in the pure gauge theory up to power corrections. We show, by precise measurements of ratios of scales defined from the Wilson flow, that these corrections are very small and that they can be described by a term proportional to M−2 down to masses in the region of the charm quark mass.

The Abraham–Lorentz force is a finite remnant of the UV singular structure of the self-interaction of a point charge with its own field. The satisfactory description of such an interaction needs a relativistic regulator. This turns out to be a problematic point because the energy of regulated relativistic cutoff theories is unbounded from below. However, one can construct point-splitting regulators which keep the Abraham–Lorentz force stable. The classical language can be reconciled with QED by pointing out that the effective quantum theory for the electric charge supports a saddle point producing the classical radiation reaction forces. [ABSTRACT FROM AUTHOR]

Abstract Assuming for Weakly Interacting Massive Particles (WIMPs) a Maxwellian velocity distribution in the Galaxy we explore in a systematic way the relative sensitivity of an extensive set of existing and projected Dark Matter (DM) direct detection experiments to each of the 14 couplings that parameterize the most general non-relativistic (NR) effective Hamiltonian allowed by Galilean invariance for a contact interaction driving the elastic scattering off nuclei of WIMPs of spin 1/2. We perform our analysis in terms of two free parameters: the WIMP mass m χ and the ratio between the WIMP-neutron and the WIMP-proton couplings cn / cp. We include the modified signal spectral shape due to non–standard interactions when it is needed in the determination of the bound, such as in the case of background subtraction or of the application of the optimal–interval method. For each coupling, in the m χ – cn / cp plane we provide contour plots of the most stringent 90% C.L. bound on the WIMP–nucleon cross section and show the experiment providing it. We also introduce NRDD_constraints, a simple interpolating code written in Python that allows to obtain the numerical value of the bound as a function of the WIMP mass m χ and of the coupling ratio cn / cp for each NR coupling. We find that 9 experiments out of the 14 present Dark Matter searches considered in our analysis provide the most stringent bound on some of the effective couplings for a given choice of (m χ , cn / cp): this is evidence of the complementarity of different target nuclei and/or different combinations of count-rates and energy thresholds when the search of DM is extended to a wide range of possible interactions. [ABSTRACT FROM AUTHOR]

We make progress towards a derivation of a low energy effective theory for SU(2) Yang–Mills theory. This low energy action is computed to 1-loop using the renormalization group technique, taking proper care of the Slavnov–Taylor identities in the Maximal Abelian Gauge. After that, we perform the Spin-Charge decomposition in a way proposed by Faddeev and Niemi. The resulting action describes a pair of nonlinear O(3) and σ -models interacting with a scalar field. The potential of the scalar field is a Mexican hat and the location of the minima sets the energy scale of solitonic configurations of the σ -model fields whose excitations correspond to glueball states. [ABSTRACT FROM AUTHOR]

In the context of upcoming new physics searches at the LHC, we investigate the impact of multidimensional differential rates in typical LHC analyses. We discuss the properties of shape information, and argue that multidimensional rates bring limited information in the scope of a discovery, but can have a large impact on model discrimination. We also point out subtleties about systematic uncertainties cancellations and the Cauchy–Schwarz bound on interference terms. [ABSTRACT FROM AUTHOR]

We use the language of uninformative Bayesian prior choice to study the selection of appropriately simple effective models. We advocate for the prior which maximizes the mutual information between parameters and predictions, learning as much as possible from limited data. When many parameters are poorly constrained by the available data, we find that this prior puts weight only on boundaries of the parameter space. Thus, it selects a lower-dimensional effective theory in a principled way, ignoring irrelevant parameter directions. In the limit where there are sufficient data to tightly constrain any number of parameters, this reduces to the Jeffreys prior. However, we argue that this limit is pathological when applied to the hyperribbon parameter manifolds generic in science, because it leads to dramatic dependence on effects invisible to experiment. [ABSTRACT FROM AUTHOR]

We discuss the constraint on the size of QCD instanton effects in low-energy effective theory. Among various instanton effects in meson mass spectrum and dynamics, we concentrate on the instanton-induced masses of light quarks. The famous instanton-induced six-quark interaction, so-called 't Hooft vertex, could give nonperturbative quantum corrections to light quark masses. Many works have already been achieved to constrain the mass corrections in light meson system, or the system of , , and , and now we know for a fact that the instanton-induced mass of up-quark is too small to realize the solution of the strong CP problem by vanishing current mass of up-quark. In this work, we give a constraint on the instanton-induced mass correction to light quarks from the mass spectrum of heavy mesons, , , and their antiparticles. To accomplish this, the complete second-order chiral symmetry breaking terms are identified in heavy meson effective theory. We find that the strength of the constraint from heavy meson masses is at the same level of that from light mesons, and it would be made even stronger by more precise data from future factories and lattice calculations. [ABSTRACT FROM AUTHOR]

We investigate the chiral symmetry restoration/breaking of a dense, magnetized and rotating quark matter within the Nambu Jona–Lasinio model including N f = 2 and N c = 3 numbers of flavors and colors, respectively. Imposing the spectral boundary conditions as well as the positiveness of energy levels lead to a correlation between the magnetic and rotation fields such that strongly magnetized plasma can not rotate anymore. We solve the gap equation at zero and finite temperature. At finite temperature and baryon chemical potential μ B , we sketch the phase diagrams T c (μ B) and T c (R Ω) in different cases. As a result, we always observe inverse-rotational catalysis mean to decrease T c by increasing R Ω. But the magnetic field has a more complex structure in the phase diagram. For slowly rotating plasma, we find that T c decreases by increasing e B , while in the fast rotating plasma we see that T c increases by increasing e B. Also, we locate exactly the position of Critical End Point by solving the equations of first and second derivatives of effective action with respect to the order parameters, simultaneously. • Proposing a general formula to find effective action in curved space-times. • Locating the position of CEP by solving the first and second derivatives of effective action. • Seeing inverse-rotational catalysis, but a more complex structure in the magnetic field space. • Slowly(rapidly) rotating plasma has reverse(direct) magnetic-catalysis with e B. [ABSTRACT FROM AUTHOR]

Decoupling of heavy quarks at low energies can be described by means of an effective theory as shown by S. Weinberg in Ref. [1] . We study the decoupling of the charm quark by lattice simulations. We simulate a model, QCD with two degenerate charm quarks. In this case the leading order term in the effective theory is a pure gauge theory. The higher order terms are proportional to inverse powers of the charm quark mass M starting at M − 2 . Ratios of hadronic scales are equal to their value in the pure gauge theory up to power corrections. We show, by precise measurements of ratios of scales defined from the Wilson flow, that these corrections are very small and that they can be described by a term proportional to M − 2 down to masses in the region of the charm quark mass. [ABSTRACT FROM AUTHOR]