Using a sequence of effective field theories (EFTs), we calculate the rate for the leptonic decay B^-→τ^-ν_τ(γ) including real and virtual QED corrections, with a cut Ecut ≪ ΛQCD imposed on electromagnetic radiation in the B-meson rest frame. We establish a factorization theorem for the rate and evaluate it at 𝒪(α), resumming the leading logarithmic corrections to all orders in perturbation theory. The large mass mτ allows us to treat the tau lepton as a heavy fermion below μ mB mτ, leading to an EFT construction that is structurally different and noticeably simpler than that for the muon case [1]. In particular, hadron-structure dependent QED corrections can be described in terms of QED-induced B− → τ− form factors, which should be calculable on the lattice. Our analysis includes the leading ΛQCD/mτ corrections as well as the leading corrections in Ecut/ΛQCD. We show that contributions of the form ΛQCD m_B/m_τ^2 , which are naively sizable, cancel among each other. Contrary to the muon channel, structure-dependent corrections involving BB*γ transitions are numerically negligible for the tau case. The remaining logarithmic dependence on Ecut is mild. We estimate that the present uncertainty in the calculation of the structure-dependent QED corrections is about 0.5
A bstract We propose a new large N limit for the thermofield double state which at the extreme ( N = ∞) limit is dual in the bulk to a back-reacted traversable wormhole, by making use of an operator in the algebra at infinity, an algebra familiar in the literature from the study of quasi-local algebras. We also compute, from a purely algebraic perspective, the effects registered by a left universe observer due to a unitary fluctuation on the right universe of the traversable wormhole, and reproduce a result from an earlier computation by Maldacena, Stanford and Yang [1].
Quantum entanglement, a profound feature of quantum mechanics where particles share interconnected states regardless of distance, has been extensively studied in low-energy systems like photons and atoms. Exploring entanglement in high-energy particle collisions offers unique opportunities to probe quantum phenomena under extreme conditions. Here we demonstrate the observation of quantum entanglement between lambda and anti-lambda hyperons (ΛΛ) produced in electron-positron collisions via the decay of the J/ψ particle. By analyzing the angular correlations of the protons and antiprotons emerging from the subsequent weak decays of the hyperons, we identify clear signatures of entanglement that violate the limits derived for product states. This result confirms that entanglement persists through both the strong interaction production process and the weak decay processes. We further establish a general polar-azimuthal selection rule showing that azimuthal correlations are indispensable for entanglement certification in spin-1/2 fermion-antifermion systems. It is also confirmed that a significant majority of these decay events occur at spacelike separation, meaning that no classical signal could connect them. The successful detection of entanglement in this hyperon-antihyperon system establishes a new methodology and platform for measuring quantum properties in relativistic particle physics, complementing traditional approaches and opening avenues for future investigations into decoherence or symmetry violations in high-energy collisions.
Abstract Quantum entanglement, a profound feature of quantum mechanics where particles share interconnected states regardless of distance, has been extensively studied in low-energy systems like photons and atoms. Exploring entanglement in high-energy particle collisions offers unique opportunities to probe quantum phenomena under extreme conditions. Here we demonstrate the observation of quantum entanglement between lambda and anti-lambda hyperons Λ Λ ¯ $$ \left(\Lambda \overline{\Lambda}\right) $$ produced in electron-positron collisions via the decay of the J/ψ particle. By analyzing the angular correlations of the protons and antiprotons emerging from the subsequent weak decays of the hyperons, we identify clear signatures of entanglement that violate the limits derived for product states. This result confirms that entanglement persists through both the strong interaction production process and the weak decay processes. We further establish a general polar-azimuthal selection rule showing that azimuthal correlations are indispensable for entanglement certification in spin-1/2 fermion-antifermion systems. It is also confirmed that a significant majority of these decay events occur at spacelike separation, meaning that no classical signal could connect them. The successful detection of entanglement in this hyperon-antihyperon system establishes a new methodology and platform for measuring quantum properties in relativistic particle physics, complementing traditional approaches and opening avenues for future investigations into decoherence or symmetry violations in high-energy collisions.
A bstract We study the coupling matrix of 𝒩 = 2 SU( N ) gauge theories with 2 N fundamental hypermultiplets in the special vacuum, where a residual ℤ N symmetry restores nontrivial modular structure. Using symmetry and dimensional arguments, we construct its general form and identify ⌊ N /2⌋ coupling constants in their most natural basis. We show that in the massless theory these couplings transform independently under S -duality and that the bare coupling is a modular function of any of them. One coupling constant, however, plays a distinguished role, emerging in the asymptotic regime and in instanton recursion relation. In the massive case, this structure is deformed but the distinguished coupling retains its privileged role.
