739 research outputs found
Lepton universality tests with leptonic kaon decays
The NA62 experiment at CERN aims to use rare kaon decays to search for new
phenomena beyond the Standard Model. During the current short term phase (data
taking completed in years 2007-8), the ratio of leptonic
decay rates is studied, which tests the structure of weak interactions and
lepton flavour universality. In this paper, the analysis is summarized,
and the preliminary result is discussed, based on 59963 candidates collected in 2007.Comment: Proceedings of CKM2010, the 6th International Workshop on the CKM
Unitarity Triangle, University of Warwick, UK, 6-10 September 201
Trigger, reconstruction and physics performances in LHCb
LHCb is one of the four major experiments that will take data at the LHC, due
to start operation in 2007. The primary aims of LHCb are to perform precision
tests of CP violation and to search for new physics in b hadron decays. About
10^12 bb pairs will be produced in LHCb per 10^7 seconds (a nominal year) in pp
collisions with a luminosity of 2x10^32 cm^-2 s^-1. A large, high-purity sample
of b hadrons, decaying in a variety of channels, will be accumulated. LHCb will
perform a detailed study of B meson mixing, precise measurements of the angles
of the unitary triangle and investigations of rare decays in b hadrons, looking
for new physics in loop-induced processes. The LHCb detector is optimised to
reach these physics goals. Here a brief description of the reconstruction
performance is given, and the sensitivities in typical channels for the study
of Bs mixing, CP violation and rare decays are summarised.Comment: Hadron Collider Physics Symposium (HCP06) Duke University Durham,
North Carolina; May 22-26, 200
Search for B<sup>+</sup><sub>c</sub>→π<sup>+</sup>μ<sup>+</sup>μ<sup>−</sup> decays and measurement of the branching fraction ratio <i>B</i>(B<sup>+</sup><sub>c</sub>→ψ(2<i>S</i>)π<sup>+</sup>)/<i>B</i>(B<sup>+</sup><sub>c</sub>→<i>J</i>/ψπ<sup>+</sup>)
The first search for nonresonant B+c→π+μ+μ− decays is reported. The analysis uses proton-proton collision data collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9 fb−1. No evidence for an excess of signal events over background is observed and an upper limit is set on the branching fraction ratio B(B+c→π+μ+μ−)/B(B+c→J/ψπ+)<2.1×10−4 at 90% confidence level. Additionally, an updated measurement of the ratio of the B+c→ψ(2S)π+ and B+c→J/ψπ+ branching fractions is reported. The ratio B(B+c→ψ(2S)π+)/B(B+c→J/ψπ+) is measured to be 0.254±0.018±0.003±0.005, where the first uncertainty is statistical, the second systematic, and the third is due to the uncertainties on the branching fractions of the leptonic J/ψ and ψ(2S) decays. This measurement is the most precise to date and is consistent with previous LHCb results
Games for Quantum Physics Education
As the second quantum revolution comes to pass with its potential to revolutionize our lives, it becomes increasingly relevant to educate the public about quantum mechanics. Quantum literacy is also a formidable challenge and opportunity for a massive cultural uplift, since it fosters the possibility for citizens to engender their creativity and practice a new way of thinking. However, quantum theory is highly counterintuitive, manifesting in a reality we have no direct experience of, and represented by mathematically difficult formalisms. Here, we propose that games can provide a playground for engaging forms of experimental and symbolic literacy accessible to anyone. We discuss the theoretical foundations underlying this idea in the framework of a global educational strategy, illustrate existing examples of its implementation along different dimensions related to educational, citizen-science, and age-related contexts, and envision future challenges
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