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Ramirez-Uribe, S., Renteria-Olivo, A. E., Rodrigo, G., Sborlini, G. F. R., & Vale Silva, L. (2022). Quantum algorithm for Feynman loop integrals. J. High Energy Phys., 05(5), 100–32pp.
Abstract: We present a novel benchmark application of a quantum algorithm to Feynman loop integrals. The two on-shell states of a Feynman propagator are identified with the two states of a qubit and a quantum algorithm is used to unfold the causal singular configurations of multiloop Feynman diagrams. To identify such configurations, we exploit Grover's algorithm for querying multiple solutions over unstructured datasets, which presents a quadratic speed-up over classical algorithms when the number of solutions is much smaller than the number of possible configurations. A suitable modification is introduced to deal with topologies in which the number of causal states to be identified is nearly half of the total number of states. The output of the quantum algorithm in IBM Quantum and QUTE Testbed simulators is used to bootstrap the causal representation in the loop-tree duality of representative multiloop topologies. The algorithm may also find application and interest in graph theory to solve problems involving directed acyclic graphs.
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LHCb Collaboration(Aaij, R. et al), Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., & Ruiz Vidal, J. (2022). Measurement of the lifetimes of promptly produced Omega(0)(c) and Xi(9)(c) baryons. Sci. Bull., 67(5), 479–487.
Abstract: A measurement of the lifetimes of the Omega(0)(c) and Xi(0)(c) baryons is reported using proton-proton collision data at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb(-1) collected by the LHCb experiment. The Omega(0)(c) and Xi(0)(c) baryons are produced directly from proton interactions and reconstructed in the pK(-)K(-)pi(+) final state. The Omega(0)(c) lifetime is measured to be 276.5 +/- 13.4 +/- 4.4 +/- 0.7 fs, and the Xi(0)(c) lifetime is measured to be 148.0 +/- 2.3 +/- 2.2 +/- 0.2 fs, where the first uncertainty is statistical, the second systematic, and the third due to the uncertainty on the D-0 lifetime. These results confirm previous LHCb measurements based on semileptonic beauty-hadron decays, which disagree with earlier results of a four times shorter Omega(c)0 lifetime, and provide the single most precise measurement of the Omega(0 )(c)lifetime.
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Capozzi, F., & Petcov, S. T. (2022). Neutrino tomography of the Earth with ORCA detector. Eur. Phys. J. C, 82(5), 461–23pp.
Abstract: Using PREM as a reference model for the Earth density distribution we investigate the sensitivity of ORCA detector to deviations of the Earth (i) outer core (OC) density, (ii) inner core (IC) density, (iii) total core density, and (iv) mantle density, from their respective PREM densities. The analysis is performed by studying the effects of the Earth matter on the oscillations of atmospheric nu(mu), nu(e), (nu) over bar (mu) and (nu) over bar (e). We present results which illustrate the dependence of the ORCA sensitivity to the OC, IC, core and mantle densities on the type of systematic uncertainties used in the analysis, on the value of the atmospheric neutrino mixing angle theta(23), on whether the Earth mass constraint is implemented or not, and on the way it is implemented, and on the type – with normal ordering (NO) or inverted ordering (IO) – of the light neutrino mass spectrum. We show, in particular, that in the “most favorable” NO case of implemented Earth mass constraint, “minimal” systematic errors and sin(2) theta(23) = 0.58, ORCA can determine, e.g., the OC (mantle) density at 3 sigma C.L. after 10 years of operation with an uncertainty of (- 18%)/+ 15% (of (- 6%)/+ 8%). In the “most disfavorable” NO case of “conservative” systematic errors and sin(2) theta(23) = 0.42, the uncertainty on OC (mantle) density reads (- 43%)/+ 39% ((- 17%/+ 20%), while for for sin(2) theta(23) = 0.50 and 0.58 it is noticeably smaller: (- 37)%/+ 30% and (- 30%)/+ 24% ((- 13%)/+ 16% and (- 11%/+ 14%)). We find also that the sensitivity of ORCA to the OC, core and mantle densities is significantly worse for IO neutrino mass spectrum.
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Camarda, S., Cieri, L., Ferrera, G., & Urtasun-Elizari, J. (2022). Higgs boson production at the LHC: fast and precise predictions in QCD at higher orders. Eur. Phys. J. C, 82(5), 492–8pp.
Abstract: We present a new numerical program, HTurbo, which provides fast and numerically precise predictions for Higgs boson production cross sections. The present version of the code implements the perturbative QCD expansion up to the next-to-next-to-leading order also combined with the resummation of the large logarithmic corrections at small transverse momenta up to next-to-next-to-leading logarithmic accuracy and it includes the Higgs boson production through gluon fusion and decay in two photons with the full dependence on the final-state kinematics. Arbitrary kinematical cuts can be applied to the final states in order to obtain fiducial cross sections and associated kinematical distributions. We present a benchmark comparison with the predictions obtained with the numerical programs HRes and HNNLO programs for which HTurbo represents an improved reimplementation.
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ATLAS Collaboration(Aad, G. et al), Amos, K. R., Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Cardillo, F., et al. (2022). Determination of the parton distribution functions of the proton using diverse ATLAS data from pp collisions at root s=7, 8 and 13 TeV. Eur. Phys. J. C, 82(5), 438–70pp.
Abstract: This paper presents an analysis at next-to-next-to-leading order in the theory of quantum chromodynamics for the determination of a new set of proton parton distribution functions using diverse measurements in pp collisions at root s = 7, 8 and 13 TeV, performed by the ATLAS experiment at the Large Hadron Collider, together with deep inelastic scattering data from ep collisions at the HERA collider. The ATLAS data sets considered are differential cross-section measurements of inclusive W-+/- and Z/gamma* boson production, W-+/- and Z boson production in association with jets, t (t) over bar production, inclusive jet production and direct photon production. In the analysis, particular attention is paid to the correlation of systematic uncertainties within and between the various ATLAS data sets and to the impact of model, theoretical and parameterisation uncertainties. The resulting set of parton distribution functions is called ATLASpdf21.
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Alioli, S., Fuster, J., Garzelli, M. V., Gavardi, A., Irles, A., Melini, D., et al. (2022). Phenomenology of t(t)over-barj plus X production at the LHC. J. High Energy Phys., 05(5), 146–63pp.
Abstract: We present phenomenological results for t (t) over barj + X production at the Large Hadron Collider, of interest for designing forthcoming experimental analyses of this process. We focus on those cases where the t (t) over barj + X process is considered as a signal. We discuss present theoretical uncertainties and the dependence on relevant input parameters entering the computation. For the R. distribution, which depends on the invariant mass of the t (t) over barj-system, we present reference predictions in the on-shell, (MS) over bar and MSR top-quark mass renormalization schemes, applying the latter scheme to this process for the first time. Our conclusions are particularly interesting for those analyses aiming at extracting the topquark mass from cross-section measurements.
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Boudet, S., Bombacigno, F., Olmo, G. J., & Porfirio, P. (2022). Quasinormal modes of Schwarzschild black holes in projective invariant Chern-Simons modified gravity. J. Cosmol. Astropart. Phys., 05(5), 032–29pp.
Abstract: We generalize the Chern-Simons modified gravity to the metric-affine case and impose projective invariance by supplementing the Pontryagin density with homothetic curvature terms which do not spoil topologicity. The latter is then broken by promoting the coupling of the Chern-Simons term to a (pseudo)-scalar field. The solutions for torsion and nonmetricity are derived perturbatively, showing that they can be iteratively obtained from the background fields. This allows us to describe the dynamics for the metric and the scalar field perturbations in a self-consistent way, and we apply the formalism to the study of quasi normal modes in a Schwarzschild black hole background. Unlike in the metric formulation of this theory, we show that the scalar field is endowed with dynamics even in the absence of its kinetic term in the action. Finally, using numerical methods we compute the quasinormal frequencies and characterize the late-time power law tails for scalar and metric perturbations, comparing the results with the outcomes of the purely metric approach.
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Figueroa, D. G., Raatikainen, S., Rasanen, S., & Tomberg, E. (2022). Implications of stochastic effects for primordial black hole production in ultra-slow-roll inflation. J. Cosmol. Astropart. Phys., 05(5), 027–48pp.
Abstract: We study the impact of stochastic noise on the generation of primordial black hole (PBH) seeds in ultra-slow-roll (USR) inflation with numerical simulations. We consider the non-linearity of the system by consistently taking into account the noise dependence on the inflaton perturbations, while evolving the perturbations on the coarse-grained background affected by the noise. We capture in this way the non-Markovian nature of the dynamics, and demonstrate that non-Markovian effects are subleading. Using the Delta N formalism, we find the probability distribution P(R) of the comoving curvature perturbation R. We consider inflationary potentials that fit the CMB and lead to PBH dark matter with i) asteroid, ii) solar, or iii) Planck mass, as well as iv) PBHs that form the seeds of supermassive black holes. We find that stochastic effects enhance the PBH abundance by a factor of O(10)-O(10(8)), depending on the PBH mass. We also show that the usual approximation, where stochastic kicks depend only on the Hubble rate, either underestimates or overestimates the abundance by orders of magnitude, depending on the potential. We evaluate the gauge dependence of the results, discuss the quantum-to-classical transition, and highlight open issues of the application of the stochastic formalism to USR inflation.
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Garani, R., & Palomares-Ruiz, S. (2022). Evaporation of dark matter from celestial bodies. J. Cosmol. Astropart. Phys., 05(5), 042–53pp.
Abstract: Scatterings of galactic dark matter (DM) particles with the constituents of celestial bodies could result in their accumulation within these objects. Nevertheless, the finite temperature of the medium sets a minimum mass, the evaporation mass, that DM particles must have in order to remain trapped. DM particles below this mass are very likely to scatter to speeds higher than the escape velocity, so they would be kicked out of the capturing object and escape. Here, we compute the DM evaporation mass for all spherical celestial bodies in hydrostatic equilibrium, spanning the mass range [10(-)(10) – 10(2)] M-circle dot, for constant scattering cross sections and s-wave annihilations. We illustrate the critical importance of the exponential tail of the evaporation rate, which has not always been appreciated in recent literature, and obtain a robust result: for the geometric value of the scattering cross section and for interactions with nucleons, at the local galactic position, the DM evaporation mass for all spherical celestial bodies in hydrostatic equilibrium is approximately given by E-c/T-chi similar to 30, where E-c is the escape energy of DM particles at the core of the object and T-chi is their temperature. In that case, the minimum value of the DM evaporation mass is obtained for super-Jupiters and brown dwarfs, m(ev)(ap) similar or equal to 0.7 GeV. For other values of the scattering cross section, the DM evaporation mass only varies by a factor smaller than three within the range 10(-41) cm(2) <= sigma(p) <= 10(-31) cm(2), where sigma(p) is the spin-independent DM-nucleon scattering cross section. Its dependence on parameters such as the galactic DM density and velocity, or the scattering and annihilation cross sections is only logarithmic, and details on the density and temperature profiles of celestial bodies have also a small impact.
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NEXT Collaboration(Novella, P. et al), Carcel, S., Carrion, J. V., Diaz, J., Martin-Albo, J., Martinez, A., et al. (2022). Measurement of the Xe-136 two-neutrino double-beta-decay half-life via direct background subtraction in NEXT. Phys. Rev. C, 105(5), 055501–8pp.
Abstract: We report a measurement of the half-life of the Xe-136 two-neutrino double-beta decay performed with a novel direct-background-subtraction technique. The analysis relies on the data collected with the NEXT-White detector operated with Xe-136-enriched and Xe-136-depleted xenon, as well as on the topology of double-electron tracks. With a fiducial mass of only 3.5 kg of Xe, a half-life of 2.34(-0.46)(+0.80) (stat)(-0.17)(+0.30) (sys) x 10(21) yr is derived from the background-subtracted energy spectrum. The presented technique demonstrates the feasibility of unique background-model-independent neutrinoless double-beta-decay searches.
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