Nearly 50 years ago, theoretical physicists proposed that a field permeates the universe and gives energy to the vacuum. This field was required to explain why some, but not all, fundamental particles have mass. Numerous precision measurements during recent decades have provided indirect support for the existence of this field, but one crucial prediction of this theory has remained unconfirmed despite 30 years of experimental searches: the existence of a massive particle, the standard model Higgs boson. The ATLAS experiment at the Large Hadron Collider at CERN has now observed the production of a new particle with a mass of 126 giga–electron volts and decay signatures consistent with those expected for the Higgs particle. This result is strong support for the standard model of particle physics, including the presence of this vacuum field. The existence and properties of the newly discovered particle may also have consequences beyond the standard model itself. The discovery paper (PLB 716(2012)129) has been up to now cited more than 2200 times.
COBISS.SI-ID: 26464551
A search is performed for WH production with a light Higgs boson decaying to hidden-sector particles resulting in clusters of collimated electrons, known as electron-jets. The search is performed with 2.04 fb−1 of data collected in 2011 with the ATLAS detector at the LHC in proton–proton collisions at √s = 7 TeV. One event satisfying the signal selection criteria is observed, which is consistent with the expected background rate. Limits on the product of the WH production cross section and the branching ratio of a Higgs boson decaying to prompt electron-jets are calculated as a function of a Higgs boson mass in the range from 100 GeV to 140 GeV. Based on PhD thesis of A. Tykhonov.
COBISS.SI-ID: 26748455
Search for processes beyond the Standard Model are performed using decays which are predicted to be rare within the latter. Among numerous publications on such searches we should emphasize a few with a large impact, exhibiting some (not yet siognificant) deviations from the Standard Model.
COBISS.SI-ID: 23094055
Constraints and tests of the New Physics models which are complementary to those arising from the B meson measurements arise from the studies of charm hadrons. Recently important efforts were put into this area of research, from which we emphasize the following publications:
COBISS.SI-ID: 27040295
Micro-strip detectors made by implanting n-type readout strips on p-type silicon bulk (n+p) are promising candidates for tracking detectors for applications in extremely high radiation fields such as those expected in experiments at Super-LHC. In this paper, we present measurements of signals in n+p strip detectors caused by fast electrons from a 90Sr source and read out by an SCT128A chip. Detectors were irradiated with reactor neutrons up to 10^16 n_eq/cm^2. The collected charge was measured at different bias voltages, and measurements were taken up to very high voltages of 1700 V. We measured the most probable value of collected charge as high as before irradiation with detectors irradiated up to 3×10^15 n_eq/cm^2. Excellent performance with nearly 50% of the charge collected was also obtained with the detector irradiated to 10^16 n_eq/cm^2. In subsequent papers the effect was confirmed as charge multiplication with impact ionization and silicon proven to work at fluences beyond 10^17 n_eq/cm^2.
COBISS.SI-ID: 22608423