In this paper Quantum Mechanics with Fundamental Length is chosen as Quantum Mechanics at Planck's scale. This is possible due to the presence in the theory of General Uncertainty Relations. Here Quantum Mechanics with Fundamental Length is obtained as a deformation of Quantum Mechanics. The distinguishing feature of the proposed approach in comparison with previous ones, lies on the fact that here density matrix subjects to deformation whereas so far commutators have been deformed. The density matrix obtained by deformation of quantum-mechanical density one is named throughout this paper density pro-matrix. Within our approach two main features of Quantum Mechanics are conserved: the probabilistic interpretation of the theory and the well-known measuring procedure corresponding to that interpretation. The proposed approach allows to describe dynamics. In particular, the explicit form of deformed Liouville's equation and the deformed Shrödinger's picture are given. Some implications of obtained results are discussed. In particular, the problem of singularity, the hypothesis of cosmic censorship, a possible improvement of the definition of statistical entropy and the problem of information loss in black holes are considered. It is shown that obtained results allow to deduce in a simple * Phone (+375) 172 883438; e-mail: a.shalyt@mail.ru; alexm@hep.by † Phone (+375) 172 883438; e-mail: suarez@hep.by, jsuarez@mail.tut.by 1 and natural way the Bekenstein-Hawking's formula for black hole entropy in semiclassical approximation.

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The CMS collaborationAbstract: A measurement of the exclusive two-photon production of muon pairs in proton-proton collisions at √ s = 7 TeV, pp → pµ + µ − p, is reported using data corresponding to an integrated luminosity of 40 pb −1 . For muon pairs with invariant mass greater than 11.5 GeV, transverse momentum p T (µ) > 4 GeV and pseudorapidity |η(µ)| < 2.1, a fit to the dimuon p T (µ + µ − ) distribution results in a measured cross section of σ(p → pµ + µ − p) = 3.38 +0.58 −0.55 (stat.) ± 0.16 (syst.) ± 0.14 (lumi.) pb, consistent with the theoretical prediction evaluated with the event generator Lpair. The ratio to the predicted cross section is 0.83 +0.14 −0.13 (stat.) ± 0.04 (syst.) ± 0.03 (lumi.). The characteristic distributions of the muon pairs produced via γγ fusion, such as the muon acoplanarity, the muon pair invariant mass and transverse momentum agree with those from the theory.

The explicit exact expressions of QED lowest-order radiative corrections to the two polarized identical fermion scattering are presented in covariant form. Polarization effects are treated in detail. The infrared divergence from the real photon emission is extracted by covariant approach. Some numerical results for Møller scattering are given.

DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6 $$\times $$ ×  6 $$\times $$ ×  6 m$$^3$$ 3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019–2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.