We study the polarization observables of J/ψ hadroproduction at next-to-leading order within the factorization formalism of nonrelativistic quantum chromodynamics. We complete the present knowledge of the relativistic corrections by also providing the contribution due to the intermediate (3)P(J)([8]) color-octet states at this order, which turns out to be quite significant. Exploiting the color-octet long-distance matrix elements previously extracted through a global fit to experimental data of unpolarized J/ψ production, we provide theoretical predictions in the helicity and Collins-Soper frames and compare them with data taken by CDF at Fermilab Tevatron I and II and by ALICE at CERN LHC. The notorious CDF J/ψ polarization anomaly familiar from leading-order analyses persists at the quantum level, while the situation looks promising for the LHC, which is bound to bring final clarification.
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http://dx.doi.org/10.1103/PhysRevLett.108.172002 | DOI Listing |
Nanoscale Horiz
August 2022
WRH Program, International Research Frontiers Initiative (IRFI) Tokyo Institute of Technology, Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.
Polarisation analysis of light-matter interactions established for propagating optical far-fields is now extended into an evanescent field as demonstrated in this study using an attenuated total reflection (ATR) setup and a synchrotron source at THz frequencies. Scalar intensity , rather than a vector -field, is used for absorbance analysis of the s- and p-components of the linearly polarised incident light. Absorption and phase changes induced by the sample and detected at the transmission port of the ATR accessory revealed previously non-accessible anisotropy in the absorption-dispersion properties of the sample probed by the evanescent optical near-field.
View Article and Find Full Text PDFRSC Adv
May 2021
Department of Transdisciplinary Science and Engineering, School of Environment and Society, Tokyo Institute of Technology 2-12-1 Ookayama, Meguro-ku Tokyo 152-8550 Japan
The mechanism of electrochemical promotion of ammonia formation was investigated by kinetic and deuterium isotope analyses using a cell with a Pt (anode)|BaCeYO (BCY)|Fe (cathode) configuration on the introduction of a gaseous mixture of H(D)-N to the cathode at 550 °C. To clarify the mechanism of electrochemical ammonia synthesis, the reaction orders for hydrogen, , and nitrogen, , were investigated. The values of and did not change after applying a negative voltage, which indicates that the reaction mechanism at rest potential is the same as that with cathodic polarization.
View Article and Find Full Text PDFNat Commun
July 2021
School of Electrical Engineering and Telecommunications, The University of New South Wales, Sydney, NSW, Australia.
A fault-tolerant quantum processor may be configured using stationary qubits interacting only with their nearest neighbours, but at the cost of significant overheads in physical qubits per logical qubit. Such overheads could be reduced by coherently transporting qubits across the chip, allowing connectivity beyond immediate neighbours. Here we demonstrate high-fidelity coherent transport of an electron spin qubit between quantum dots in isotopically-enriched silicon.
View Article and Find Full Text PDFNanomaterials (Basel)
October 2019
State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing 100084, China.
Birefringence of 3 × 10 - 3 is demonstrated inside cross-sectional regions of 100 μ m, inscribed by axially stretched Bessel-beam-like fs-laser pulses along the c-axis inside sapphire. A high birefringence and retardance of λ / 4 at mid-visible spectral range (green) can be achieved using stretched beams with axial extension of 30-40 μ m. Chosen conditions of laser-writing ensure that there are no formations of self-organized nano-gratings.
View Article and Find Full Text PDFSci Rep
December 2018
Tokyo Institute of Technology, Meguro-ku, Tokyo, 152-8550, Japan.
Polarised light imaging microscopy, with the addition of a liquid crystal (LC) phase retarder, was used to determine the birefringence of silk fibres with high (∼1 μm) spatial resolution. The measurement was carried out with the silk fibres (the optical slow axis) and the slow axis of the LC-retarder set at parallel angles. The direct fit of the transmission data allowed for high fidelity determination of the birefringence Δn ≈ 1.
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