Quantum theory of resonantly enhanced four-wave mixing: mean-field and exact numerical solutions

We present a full quantum analysis of resonant forward four-wave mixing based on electromagnetically induced transparency (EIT). In particular, we study the regime of efficient nonlinear conversion with low-intensity fields that has been predicted from a semiclassical analysis. We derive an effective nonlinear interaction Hamiltonian in the adiabatic limit. In contrast to conventional nonlinear optics this Hamiltonian does not have a power expansion in the fields and the conversion length increases with the input power. We analyze the stationary wave-mixing process in the forward scattering configuration using an exact numerical analysis for up to $10^3$ input photons and compare the results with a mean-field approach. Due to quantum effects, complete conversion from the two pump fields into the signal and idler modes is achieved only asymptotically for large coherent pump intensities or for pump fields in few-photon Fock states. The signal and idler fields are perfectly quantum correlated which has potential applications in quantum communication schemes. We also discuss the implementation of a single-photon phase gate for continuous quantum computation.Comment: 10 pages, 11 figure

Full quantum solutions to the resonant four-wave mixing of two single-photon wave packets

We analyze both analytically and numerically the resonant four-wave mixing of two co-propagating single-photon wave packets. We present analytic expressions for the two-photon wave function and show that soliton-type quantum solutions exist which display a shape-preserving oscillatory exchange of excitations between the modes. Potential applications including quantum information processing are discussed.Comment: 7 pages, 3 figure

Erratum to: Insight into particle production mechanisms via angular correlations of identified particles in pp collisions at s = 7 TeV (The European Physical Journal C, (2017), 77, 8, (569), 10.1140/epjc/s10052-017-5129-6)

We have identified a mistake in how Fig. 1 is referenced in the text of the article Eur. Phys. J. C 77 (2017) no. 8, 569 which affected three paragraphs of the results section. The corrected three paragraphs as well as the unmodified accompanying figure are reproduced in this document with the correct labeling. In addition, an editing issue led to a missing acknowledgements section. The missing section is reproduced at the end of this document in the manner in which it should have appeared in the published article. © 2019, CERN for the benefit of the ALICE collaboration

Publisher Correction: Unveiling the strong interaction among hadrons at the LHC (Nature, (2020), 588, 7837, (232-238), 10.1038/s41586-020-3001-6)

In Fig. 1c of this Article, owing to an error during the production process, the equation incorrectly began ‘C(k*, r*) = …’ instead of ‘C(k*) = …’. In addition, in affiliation 71 ‘Dipartimento di Fisica dell’Università degli studi di Bari Aldo Moro’ has been corrected to read ‘Dipartimento di Fisica dell’Università degli studi di Cagliari’. The original Article has been corrected online. *A list of authors and their affiliations appears online. © 2021, The Author(s), under exclusive licence to Springer Nature Limited

Calibration of the photon spectrometer PHOS of the ALICE experiment

The procedure for the energy calibration of the high granularity electromagnetic calorimeter PHOS of the ALICE experiment is presented. The methods used to perform the relative gain calibration, to evaluate the geometrical alignment and the corresponding correction of the absolute energy scale, to obtain the nonlinearity correction coefficients and finally, to calculate the time-dependent calibration corrections, are discussed and illustrated by the PHOS performance in proton-proton (pp) collisions at s=13 TeV. After applying all corrections, the achieved mass resolutions for \u3c00 and \u3b7 mesons for pT > 1.7 GeV/c are \u3c3m\u3c0javax.xml.bind.JAXBElement@533d1c3d = 4.56 \ub1 0.03 MeV/c2 and \u3c3m\u3b7 = 15.3 \ub1 1.0 MeV/c2, respectively

Energy dependence of exclusive J/ photoproduction off protons in ultra-peripheral p-Pb collisions at NN=5.02 TeV

The ALICE Collaboration has measured the energy dependence of exclusive photoproduction of J / \u3c8 vector mesons off proton targets in ultra\u2013peripheral p\u2013Pb collisions at a centre-of-mass energy per nucleon pair sNN=5.02 TeV. The e + e - and \u3bc + \u3bc - decay channels are used to measure the cross section as a function of the rapidity of the J / \u3c8 in the range - 2.5 < y< 2.7 , corresponding to an energy in the \u3b3p centre-of-mass in the interval 40 < W \u3b3p < 550 GeV. The measurements, which are consistent with a power law dependence of the exclusive J / \u3c8 photoproduction cross section, are compared to previous results from HERA and the LHC and to several theoretical models. They are found to be compatible with previous measurements