Measurement of matter–antimatter differences in beauty baryon decays

Differences in the behaviour of matter and antimatter have been observed in K and B meson decays, but not yet in any baryon decay. Such differences are associated with the non-invariance of fundamental interactions under the combined charge-conjugation and parity transformations, known as CP violation. Here, using data from the LHCb experiment at the Large Hadron Collider, we search for CP-violating asymmetries in the decay angle distributions of Lambda(0)(b) baryons decaying to p pi(-) pi(+) pi(-) and p pi(-) K+K- final states. These four-body hadronic decays are a promising place to search for sources of CP violation both within and beyond the standard model of particle physics. We find evidence for CP violation in Lambda(0)(b) to p pi(-) pi(+) pi(-) decays with a statistical significance corresponding to 3.3 standard deviations including systematic uncertainties. This represents the first evidence for CP violation in the baryon sector

Differential branching fractions and isospin asymmetries of B → K (*) μ + μ - decays

The isospin asymmetries of B → Kμ + μ - and B → K * μ + μ - decays and the partial branching fractions of the B 0 → K 0 μ + μ -, B + → K + μ + μ - and B + → K *+ μ + μ - decays are measured as functions of the dimuon mass squared, q 2. The data used correspond to an integrated luminosity of 3 fb-1 from proton-proton collisions collected with the LHCb detector at centre-of-mass energies of 7 TeV and 8 TeV in 2011 and 2012, respectively. The isospin asymmetries are both consistent with the Standard Model expectations. The three measured branching fractions favour lower values than their respective theoretical predictions, however they are all individually consistent with the Standard Model. [Figure not available: see fulltext.] © 2014 The Author(s)

Descriptions of some new species of spiders from British India

Volume: 13Start Page: 478End Page: 49