
AGATA Collaboration(Cederwall, B. et al), Gadea, A., Jurado, M., DomingoPardo, C., Huyuk, T., & PerezVidal, R. M. (2020). Isospin Properties of Nuclear Pair Correlations from the Level Structure of the SelfConjugate Nucleus Ru88. Phys. Rev. Lett., 124(6), 062501–6pp.
Abstract: The lowlying energy spectrum of the extremely neutrondeficient selfconjugate (N = Z) nuclide Ru88(44)44 has been measured using the combination of the Advanced Gamma Tracking Array (AGATA) spectrometer, the NEDA and Neutron Wall neutron detector arrays, and the DIAMANT charged particle detector array. Excited states in Ru88 were populated via the Fe54(Ar36, 2n gamma)Ru88* fusionevaporation reaction at the Grand Accelerateur National d'Ions Lourds (GANIL) accelerator complex. The observed gammaray cascade is assigned to Ru88 using clean prompt gammagamma2neutron coincidences in anticoincidence with the detection of charged particles, confirming and extending the previously assigned sequence of lowlying excited states. It is consistent with a moderately deformed rotating system exhibiting a band crossing at a rotational frequency that is significantly higher than standard theoretical predictions with isovector pairing, as well as observations in neighboring N > Z nuclides. The direct observation of such a “delayed” rotational alignment in a deformed N = Z nucleus is in agreement with theoretical predictions related to the presence of strong isoscalar neutronproton pair correlations.



AGATA Collaboration(Crespi, F. C. L. et al), & Gadea, A. (2014). Isospin Character of LowLying Pygmy Dipole States in Pb208 via Inelastic Scattering of O17 Ions. Phys. Rev. Lett., 113(1), 012501–5pp.
Abstract: The properties of pygmy dipole states in Pb208 were investigated using the Pb208(O17, O17'gamma) reaction at 340 MeV and measuring the gamma decay with high resolution with the AGATA demonstrator array. Cross sections and angular distributions of the emitted gamma rays and of the scattered particles were measured. The results are compared with (gamma, gamma') and (p, p') data. The data analysis with the distorted wave Born approximation approach gives a good description of the elastic scattering and of the inelastic excitation of the 2(+) and 3() states. For the dipole transitions a form factor obtained by folding a microscopically calculated transition density was used for the first time. This has allowed us to extract the isoscalar component of the 1() excited states from 4 to 8 MeV.



AGATA Collaboration(HadynskaKlek, K. et al), & Gadea, A. (2016). Superdeformed and Triaxial States in Ca42. Phys. Rev. Lett., 117(6), 062501–7pp.
Abstract: Shape parameters of a weakly deformed groundstate band and highly deformed slightly triaxial sideband in Ca42 were determined from E2 matrix elements measured in the first lowenergy Coulomb excitation experiment performed with AGATA. The picture of two coexisting structures is well reproduced by new stateoftheart largescale shell model and beyondmeanfield calculations. Experimental evidence for superdeformation of the band built on 0(2)(+) has been obtained and the role of triaxiality in the A similar to 40 mass region is discussed. Furthermore, the potential of Coulomb excitation as a tool to study superdeformation has been demonstrated for the first time.



AguileraVerdugo, J. J., DriencourtMangin, F., HernandezPinto, R. J., Plenter, J., RamirezUribe, S., RenteriaOlivo, A. E., et al. (2020). Open Loop Amplitudes and Causality to All Orders and Powers from the LoopTree Duality. Phys. Rev. Lett., 124(21), 211602–6pp.
Abstract: Multiloop scattering amplitudes describing the quantum fluctuations at highenergy scattering processes are the main bottleneck in perturbative quantum field theory. The looptree duality is a novel method aimed at overcoming this bottleneck by opening the loop amplitudes into trees and combining them at integrand level with the realemission matrix elements. In this Letter, we generalize the looptree duality to all orders in the perturbative expansion by using the complex Lorentzcovariant prescription of the original oneloop formulation. We introduce a series of mutiloop topologies with arbitrary internal configurations and derive very compact and factorizable expressions of their opentotrees representation in the looptree duality formalism. Furthermore, these expressions are entirely independent at integrand level of the initial assignments of momentum flows in the Feynman representation and remarkably free of noncausal singularities. These properties, that we conjecture to hold to other topologies at all orders, provide integrand representations of scattering amplitudes that exhibit manifest causal singular structures and better numerical stability than in other representations.



Agullo, I., del Rio, A., & NavarroSalas, J. (2017). Electromagnetic Duality Anomaly in Curved Spacetimes. Phys. Rev. Lett., 118(11), 111301–5pp.
Abstract: The sourcefree Maxwell action is invariant under electricmagnetic duality rotations in arbitrary spacetimes. This leads to a conserved classical Noether charge. We show that this conservation law is broken at the quantum level in the presence of a background classical gravitational field with a nontrivial ChernPontryagin invariant, in parallel with the chiral anomaly for massless Dirac fermions. Among the physical consequences, the net polarization of the quantum electromagnetic field is not conserved.



Agullo, I., NavarroSalas, J., Olmo, G. J., & Parker, L. (2010). Hawking Radiation by Kerr Black Holes and Conformal Symmetry. Phys. Rev. Lett., 105(21), 211305–4pp.
Abstract: The exponential blueshift associated with the event horizon of a black hole makes conformal symmetry play a fundamental role in accounting for its thermal properties. Using a derivation based on twopoint functions, we show that the full spectrum of thermal radiation of scalar particles by Kerr black holes can be explicitly derived on the basis of a conformal symmetry arising in the wave equation near the horizon. The simplicity of our approach emphasizes the depth of the connection between conformal symmetry and black hole radiance.



Algora, A. et al, Jordan, D., Tain, J. L., Rubio, B., Agramunt, J., PerezCerdan, A. B., et al. (2010). Reactor Decay Heat in Pu239: Solving the gamma Discrepancy in the 43000s Cooling Period. Phys. Rev. Lett., 105(20), 202501–4pp.
Abstract: The beta feeding probability of Tc102,Tc 104,Tc 105,Tc 106,Tc 107, Mo105, and Nb101 nuclei, which are important contributors to the decay heat in nuclear reactors, has been measured using the total absorption technique. We have coupled for the first time a total absorption spectrometer to a Penning trap in order to obtain sources of very high isobaric purity. Our results solve a significant part of a longstanding discrepancy in the gamma component of the decay heat for Pu239 in the 43000 s range.



Aparisi, J., Fuster, J., Irles, A., Rodrigo, G., Vos, M., Yamamoto, H., et al. (2022). m(b) at m(H): The Running Bottom Quark Mass and the Higgs Boson. Phys. Rev. Lett., 128(12), 122001–7pp.
Abstract: We present a new measurement of the bottom quark mass in the MS scheme at the renormalization scale of the Higgs boson mass from measurements of Higgs boson decay rates at the LHC: 0.31 GeV. The measurement has a negligible theory uncertainty and excellent prospects to improve at the HLLHC and a future Higgs factory. Confronting this result and mb(mb) from lowenergy measurements and mb(mZ) from Zpole data, with the prediction of the scale evolution of the renormalization group equations, we find strong evidence for the “running” of the bottom quark mass.



ATF2 Collaboration(White, G. R. et al), Blanch, C., FausGolfe, A., & RestaLopez, J. (2014). Experimental Validation of a Novel Compact Focusing Scheme for Future EnergyFrontier Linear Lepton Colliders. Phys. Rev. Lett., 112(3), 034802–6pp.
Abstract: A novel scheme for the focusing of highenergy leptons in future linear colliders was proposed in 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energyscaled version of the compact focusing optics designed for the ILC collider.



ATLAS and CMS Collaborations(Aad, G. et al), Aikot, A., Amos, K. R., Aparisi Pozo, J. A., Bailey, A. J., Bouchhar, N., et al. (2024). Evidence for the Higgs Boson Decay to a Z Boson and a Photon at the LHC. Phys. Rev. Lett., 132(2), 021803–32pp.
Abstract: The first evidence for the Higgs boson decay to a Z boson and a photon is presented, with a statistical significance of 3.4 standard deviations. The result is derived from a combined analysis of the searches performed by the ATLAS and CMS Collaborations with proton proton collision datasets collected at the CERN Large Hadron Collider (LHC) from 2015 to 2018. These correspond to integrated luminosities of around 140 fb1 for each experiment, at a center of mass energy of 13 TeV. The measured signal yield is 2.2 +/ 0.7 times the standard model prediction, and agrees with the theoretical expectation within 1.9 standard deviations.

