Abstract: Here we present the experimental activities carried out at ISOLDE with the total absorption spectrometer Lucrecia, a large 4 pi scintillator detector designed to absorb a full gamma cascade following beta decay. This spectrometer is designed to measure beta-feeding to excited states without the systematic error called Pandemonium. The set up allows the measurement of decays of very short half life. Experimental results from several campaigns, that focus on the determination of the shapes of beta-decaying nuclei by measuring their beta decay strength distributions as a function of excitation energy in the daughter nucleus, are presented.

Abstract: A search for CP violation in the decay Lambda(0)(b) -> pK(-)mu(+)mu(-) is presented. This decay is mediated by flavour-changing neutral-current transitions in the Standard Model and is potentially sensitive to new sources of CP violation. The study is based on a data sample of proton-proton collisions recorded with the LHCb experiment, corresponding to an integrated luminosity of 3 fb(-1). The Lambda(0)(b) -> pK(-)mu(+)mu(-) decay is observed for the first time, and two observables that are sensitive to different manifestations of CP violation are measured, Delta A(CP) equivalent to A(CP) (Lambda(0)(b) -> pK(-)mu(+)mu(-)) – A(CP) (Lambda(0)(b) -> pK(-)J/psi) and a(CP)((T) over cap -odd), where the latter is based on asymmetries in the angle between the mu(+)mu(-) and pK(-) decay planes. These are measured to be Delta A(CP) = (-3.5 +/- 5.0 (stat) +/- 0.2 (syst)) x 10(-2), a(CP)((T) over cap -odd) = (1.2 +/- 5.0 (stat) +/- 0.7 (syst)) x 10(-2), and no evidence for CP violation is found.

Abstract: A Standard Model extension with two Majorana neutrinos can explain the measured neutrino masses and mixings, and also account for the matter-antimatter asymmetry in a region of parameter space that could be testable in future experiments. The testability of the model relies to some extent on its minimality. In this paper we address the possibility that the model might be extended by extra generic new physics which we parametrize in terms of a low-energy effective theory. We consider the effects of the operators of the lowest dimensionality, d = 5, and evaluate the upper bounds on the coefficients so that the predictions of the minimal model are robust. One of the operators gives a new production mechanism for the heavy neutrinos at LHC via higgs decays. The higgs can decay to a pair of such neutrinos that, being long-lived, leave a powerful signal of two displaced vertices. We estimate the LHC reach to this process.

Abstract: We analyze the impact of QCD corrections on limits derived from neutrinoless double beta decay (0 nu beta beta ). As demonstrated previously, the effect of the color mismatch arising from loops with gluons linking the quarks from different color-singlet currents participating in the effective operators has a dramatic impact on the predictions for some particular Wilson coefficients. Here, we consider all possible contributions from heavy particle exchange, i.e. the so-called short-range mechanism of 0 nu beta beta decay. All high-scale models (HSM) in this class match at some scale around a similar to few TeV with the corresponding effective theory, containing a certain set of effective dimension-9 operators. Many of these HSM receive contributions from more than one of the basic operators and we calculate limits on these models using the latest experimental data. We also show with one nontrivial example, how to derive limits on more complicated models, in which many different Feynman diagrams contribute to 0 nu beta beta decay, using our general method.

Abstract: A measurement of the production cross section for two isolated photons in proton-proton collisions at a center-of-mass energy of root s = 8 TeV is presented. The results are based on an integrated luminosity of 20.2 fb(-1) recorded by the ATLAS detector at the Large Hadron Collider. The measurement considers photons with pseudorapidities satisfying vertical bar eta(gamma)vertical bar< 1.37 or 1.56 <vertical bar eta(gamma)vertical bar< 2.37 and transverse energies of respectively E-T,1(gamma) > 40 GeV and E-T,2(gamma) > 30 GeV for the two leading photons ordered in transverse energy produced in the interaction. The background due to hadronic jets and electrons is subtracted using data-driven techniques. The fiducial cross sections are corrected for detector effects and measured differentially as a function of six kinematic observables. The measured cross section integrated within the fiducial volume is 16.8 +/- 0.8 pb. The data are compared to fixed-order QCD calculations at next-to-leading-order and next-to-next-to-leading-order accuracy as well as next-to-leading-order computations including resummation of initial-state gluon radiation at next-to-next-to-leading logarithm or matched to a parton shower, with relative uncertainties varying from 5% to 20%.