We present results over an 11-year Solar cycle of cosmic antiprotons based on 1.1×10^{6} events in the rigidity range from 1.00 to 41.9 GV. The p[over ¯] fluxes exhibit distinct properties. The magnitude of the p[over ¯] flux temporal variation is significantly smaller than those of p, e^{-}, and e^{+}. A hysteresis between the p[over ¯] fluxes and the p fluxes is observed, whereas the p[over ¯] and e^{-} fluxes show a linear correlation. With a model-independent analysis, we found a universal relation between the shape of the rigidity spectrum and the magnitude of flux temporal variation over an 11-year Solar cycle for both positively and negatively charged particles. The simultaneous results on p[over ¯] and p, e^{-}, and e^{+} provide unique information for understanding particle transport in the Solar System as a function of mass, charge, and spectral shape.
We report the properties of precision time structures of cosmic nuclei He, Li, Be, B, C, N, and O fluxes over an 11-year solar cycle from May 2011 to November 2022 in the rigidity range from 1.92 to 60.3 GV. The nuclei fluxes show similar but not identical time variations with amplitudes decreasing with increasing rigidity. In particular, below 3.64 GV the Li, Be, and B fluxes, and below 2.15 GV the C, N, and O fluxes, are significantly less affected by solar modulation than the He flux. We observe that these differences in solar modulation are linearly correlated with the differences in the spectral indices of the cosmic nuclei fluxes. This shows, in a model-independent way, that solar modulation of galactic cosmic nuclei depends on their spectral shape. In addition, solar modulation differences due to nuclei velocity dependence on the mass-to-charge ratio (A/Z) are not observed.
We present the precision measurements of 11 years of daily cosmic electron fluxes in the rigidity interval from 1.00 to 41.9 GV based on 2.0×10^{8} electrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The electron fluxes exhibit variations on multiple timescales. Recurrent electron flux variations with periods of 27 days, 13.5 days, and 9 days are observed. We find that the electron fluxes show distinctly different time variations from the proton fluxes. Remarkably, a hysteresis between the electron flux and the proton flux is observed with a significance of greater than 6σ at rigidities below 8.5 GV. Furthermore, significant structures in the electron-proton hysteresis are observed corresponding to sharp structures in both fluxes. This continuous daily electron data provide unique input to the understanding of the charge sign dependence of cosmic rays over an 11-year solar cycle.
Studies in many areas of particle and astroparticle physics require a good knowledge of hadron spectra produced at small angles to the primary particle direction, e.g. in the TeV energy range at the LHC. The present work is dedicated to development of a particle identification technique based on the transition radiation produced by highly relativistic particles. Dedicated experimental studies were carried out and simulation models were developed to reproduce experimental data obtained with different prototypes. On the basis of these studies, the possibility of making detectors able to provide hadron composition measurement with high accuracy and identify particles with high efficiency in the forward experiments at the LHC was demonstrated. Two concepts of large scale TRDs are proposed: the straw TRD and the GaAs/straw TRD. They allow the reconstruction of hadron spectra with accuracy about or below 1% and to identify particles with high efficiency in individual events. As an example, suppression of the combinatorial background was demonstrated for the D0→K−π+ and D̄0→ K+π− decays.
In the published HTML version of this article, the affiliations of the authors of the National Research Nuclear University MEPhI, Moscow, Russia were unfortunately marked incorrectly.
Since the Higgs boson discovery in 2012, the ATLAS and CMS collaborations are performing intensive studies of its properties. Those studies include, among other things, measurements of cross sections, branching ratios, coupling constants and mass. In this paper, the current status of effective field theory interpretations of the simplified template cross section measurements is presented for different production modes and decay channels of the Higgs boson. Limits on the Higgs boson effective field theory couplings were set by using 13 TeV proton-proton collisions data recorded by the ATLAS and CMS detectors at the LHC.