Journal of High Energy Physics最新文献

We study the possibility that the Right-handed neutrino is a five-dimensional state propagating along a micron size extra dimension, as required in the dark dimension proposal. We work out the signatures of R-neutrino production in KATRIN experiment and compare them with those of a sterile neutrino which manifests by a kink in the electron energy spectrum of the beta-decay at a value corresponding to the sterile neutrino mass. We explore the allowed parameter space of the compactification scale and the R-neutrino bulk mass versus the Yukawa coupling, and show that a large part of it is within KATRIN’s sensitivity. When the bulk mass is much smaller than the compactification scale, several kinks could be observed corresponding to the positions of the R-neutrino Kaluza-Klein excitations, while for large bulk mass there will be effectively one kink at the position of the bulk mass.

Black hole normal modes have intriguing connections to logarithmic spectra, and the spectral form factor (SFF) of E_n = log n is the mod square of the Riemann zeta function ζ(s). In this paper, we first provide an analytic understanding of the dip-ramp-plateau structure of ζ(s) and show that the ramp at ( beta equiv mathfrak{R}(s)=0 ) has a slope precisely equal to 1. The s = 1 pole of ζ(s) can be viewed as due to a Hagedorn transition in this setting, and Riemann’s analytic continuation to ( mathfrak{R}(s)<1 ) provides the quantum contribution to the truncated log n partition function. This perspective yields a precise definition of ζ(s) as the “full ramp after removal of the dip”, and allows an unambiguous determination of the Thouless time. For black hole microstates, the Thouless time is expected to be ( mathcal{O}(1) ) — remarkably, the ζ(s) also exhibits this behavior. To our knowledge, this is the first black hole-inspired toy model that has a demonstrably ( mathcal{O}(1) ) Thouless time. In contrast, it is ( mathcal{O}left(log Nright) ) in the SYK model and expected to be ( mathcal{O}left({N}^{#}right) ) in supergravity fuzzballs. We trace the origins of the ramp to a certain reflection property of the functional equation satisfied by ζ(s), and suggest that it is a general feature of L-functions — we find evidence for ramps in large classes of L-functions. As an aside, we also provide an analytic determination of the slopes of (non-linear) ramps that arise in power law spectra using Poisson resummation techniques.

The inclusion of higher derivatives is a necessary condition for a renormalizable or superrenormalizable local theory of quantum gravity. On the other hand, higher derivatives lead to classical instabilities and a loss of unitarity at the quantum level. A standard way to detect such issues is by examining the reflection positivity condition and the existence of a Källén-Lehmann spectral representation for the two-point function. We demonstrate that these requirements for a consistent quantum theory are satisfied in a theory we have recently proposed. This theory is based on a six-derivative scalar field action featuring a pair of complex-mass ghost fields that form a bound state. Our results support the interpretation that physical observables can emerge from ghost dynamics in a consistent and unitary framework.

In this work, we analyze the infrared divergence of two-loop amplitudes at arbitrary multiplicity in three-dimensional ( mathcal{N}=6 ) Chern-Simons matter theory. We introduce the Bern-Dixon-Smirnov (BDS) integrand, which captures the full infrared structure while remaining free of unphysical cuts. We show that these local integrands, together with their kinematic prefactors, are naturally organized by the scaffolding triangulations of n = 2k-gon, with distinct triangulations yielding different local representations. Remarkably, this triangulation structure also persists at the level of the integrated functions. This observation provides a graphical proof of both the cancellation of elliptic cuts and the triangulation independence of the integrated result. As a direct consequence, we obtain a simple proof that the integrated BDS integrand coincides with the one-loop maximally-helicity-violating (MHV) amplitude (the BDS ansatz) of ( mathcal{N}=4 ) super Yang-Mills theory for all n = 2k.

High-temperature (q → 1) asymptotics of 4d superconformal indices of Lagrangian theories have been recently analyzed up to exponentially suppressed corrections. Here we use RG-inspired tools to extend the analysis to the exponentially suppressed terms in the context of Schur indices of ( mathcal{N}=2 ) SCFTs. In particular, our approach explains the curious patterns of logarithms (polynomials in 1/log q) found by Dedushenko and Fluder in their numerical study of the high-temperature expansion of rank-1 theories. We also demonstrate compatibility of our results with the conjecture of Beem and Rastelli that Schur indices satisfy finite-order, possibly twisted, modular linear differential equations (MLDEs), and discuss the interplay between our approach and the MLDE approach to the high-temperature expansion. The expansions for q near roots of unity are also treated. A byproduct of our analysis is a proof (for Lagrangian theories) of rationality of the conformal dimensions of all characters of the associated VOA, that mix with the Schur index under modular transformations.

We analyze the three-body decays of the long-lived neutral kaon K_L → ππa, where a is an axion-like particle (ALP), and compare them to the two-body decay K_L → π⁰a. While the latter requires both flavor violation (FV) and CP violation (CPV), the former can proceed via FV alone, allowing the ratio of decay rates to serve as a probe of CPV of the underlying UV theory. We emphasize the importance of weak-interaction-induced contributions, often neglected in recent calculations. We explore both minimal and non-minimal flavor-violating scenarios, and identify classes of models where ALP production from neutral three-body decays is comparable to — or even dominates over — the two-body decay, despite its reduced phase space. Finally, we discuss the phenomenological implications of our results and show how these decays can provide complementary probes of ALP couplings beyond those accessible via charged kaon channels.

We study a class of nonlocal conformal field theories in two dimensions which are obtained as deformations of the Virasoro minimal models. The construction proceeds by coupling a relevant primary operator ϕ_r,s of the m-th minimal model to a generalized free field, in such a way that the interaction term has scaling dimension 2 − δ. Flowing to the infrared, we reach a new class of CFTs that we call long-range minimal models. In the case r = s = 2, the resulting line of fixed points, parametrized by δ, can be studied using two perturbative expansions with different regimes of validity, one near the mean-field theory end, and one close to the long-range to short-range crossover. This is due to a straightforward generalization of an infrared duality which was proposed for the long-range Ising model (m = 3) in 2017. We find that the large-m limit is problematic in both perturbative regimes, hence nonperturbative methods will be required in the intermediate range for all values of m. For the models based on ϕ_1,2, the situation is rather different. In this case, only one perturbative expansion is known but it is well behaved at large m. We confirm this with a computation of infinitely many anomalous dimensions at two loops. Their large-m limits are obtained from both numerical extrapolations and a method we develop which carries out conformal perturbation theory using Mellin amplitudes. For minimal models, these can be accessed from the Coulomb gas representations of the correlators. This method reveals analytic expressions for some integrals in conformal perturbation theory which were previously only known numerically.

The one-loop correction to eleven-dimensional supergravity involves a cubically divergent term t₈t₈R⁴, with four Riemann tensors. A similar term (with finite coefficient) has been argued to be present in the M-theory effective action. It is expected to reduce to a similar one-loop term present in the type IIA effective action. This has previously been verified in the NSNS sector at the 4-point level. Here we extend this result to couplings of NSNS and RR fields, which have been computed using the pure spinor formalism. In particular, we check all couplings of RR fields to the dilaton as well as all couplings involving the metric and RR three-form. Correcting some minor mistakes in the literature we find complete agreement. We also give a complete analysis of 4-point terms in eleven dimensions computed previously from superparticle amplitudes and present a very simple form for these.

We present a detailed analysis of integrated correlators for an ( mathcal{N}=2 ) supercon-formal field theory on a squashed sphere with SU(N) gauge group and fundamental/anti-symmetric matter. Employing the matrix model arising from supersymmetric localisation, we compute derivatives of the partition function ( mathcal{Z} ) with respect to the fundamental mass (μ), the anti-symmetric mass (m) and the squashing parameter (b), corresponding to integrated insertions of the ( mathcal{N}=2 ) flavour-current and stress-tensor multiplets, which are holographically dual to gluon and graviton scatterings in the presence of D7-branes. For correlators dual to only graviton scatterings, we confirm the planar-limit equivalence with ( mathcal{N}=4 ) SYM. Our main result is a remarkable universality for the mixed gluon-graviton scattering amplitudes off D7-branes, obtained from ( {partial}_{mu}^2{partial}_m^2log mathcal{Z} ) and ( {partial}_{mu}^2{partial}_b^2log mathcal{Z} ). We show that the leading and sub-leading large-N contributions in the strong-coupling regime are governed by universal asymptotic series, identical to those found for integrated giant-graviton correlators in ( mathcal{N}=4 ) SYM. We also propose an SL(2, ℤ)-invariant completion of these results in terms of non-holomorphic Eisenstein series. This completion provides exact constraints on higher-derivative terms in the dual AdS₅ brane-string amplitudes and highlights an unexpected universality across distinct superconformal theories at strong coupling.

We investigate a novel theoretical structure underlying the computation of integration-by-parts relations between Feynman integrals via syzygy-based methods. Building on insights from intersection theory, we analyze the large-ϵ limit of dimensional regularization on the maximal cut, showing that total derivatives vanish on the critical locus of the logarithm of the Baikov polynomial — the locus known to govern the number of master integrals. We introduce “critical syzygies” as a distinguished subset of syzygies that captures this behavior. We show that, when the critical locus is isolated, critical syzygies generate a sufficient set of total derivatives in the large-ϵ limit. We study their structure analytically at one loop and develop a numerical approach for their construction at two loops. Our results demonstrate that critical syzygies are a valuable tool for integral reduction in cutting-edge two-loop examples, offering a novel geometric perspective on integration-by-parts relations.