Since 2015, with the restart of the LHC for its second run of data taking, the LHCb experiment has been empowered with a dedicated computing model to select and analyse calibration samples to measure ...the performance of the particle identification (PID) detectors and algorithms. The novel technique was developed within the framework of the innovative trigger model of the LHCb experiment, which relies on online event reconstruction for most of the datasets, reserving offline reconstruction to special physics cases. The strategy to select and process the calibration samples, which includes a dedicated data-processing scheme combining online and offline reconstruction, is discussed. The use of the calibration samples to measure the detector PID performance, and the efficiency of PID requirements across a large range of decay channels, is described. Applications of the calibration samples in data-quality monitoring and validation procedures are also detailed.
A
bstract
The helicity formalism applied to the radiative decay
Λ
b
0
→
pK
−
γ
is presented for the first time in this paper. The aim is to provide the necessary formalism to be able to resolve the ...resonant
pK
−
structures at the photon pole by means of an amplitude analysis. Experimental effects, such as resolution, are also discussed.
Open Science is encouraged by the European Union and many other political and scientific institutions. However, scientific practice is proving slow to change. We propose, as early career researchers, ...that it is our task to change scientific research into open scientific research and commit to Open Science principles.
The helicity formalism applied to the radiative decay $ {\varLambda}_b^0\to {pK}^{-}\gamma $ is presented for the first time in this paper. The aim is to provide the necessary formalism to be able to ...resolve the resonant pK$^{−}$ structures at the photon pole by means of an amplitude analysis. Experimental effects, such as resolution, are also discussed.
Its forward acceptance and excellent vertex resolution allow LHCb to perform competitive searches for heavy particles beyond the Standard Model. A search for Hidden Valley particles with the LHCb ...detector using 35.8 pb-1 of data at s=7 TeV is reported and prospects for searches of the stau particle presented.
The coupling of the electroweak gauge bosons of the Standard Model (SM) to leptons is flavour universal. Extensions of the SM do not necessarily have this property. Rare decays of heavy flavour are ...suppressed in the SM and new particles may give sizeable contributions to these processes, therefore, their precise study allows for sensitive tests of lepton flavour universality. Of particular interest are rare b to sll decays that are well accessible at the LHCb experiment. Recent results from LHCb on lepton flavour universality in rare b to sll decays are discussed.
Measurements of the cross section for producing b quarks in the reaction pp -> b (b) over barX are reported in 7 and 13 TeV collisions at the LHC as a function of the pseudorapidity. in the range 2 < ...eta < 5 covered by the acceptance of the LHCb experiment. The measurements are done using semileptonic decays of b-flavored hadrons decaying into a ground-state charmed hadron in association with a muon. The cross sections in the covered. range are 72.0 +/- 0.3 +/- 6.8 and 154.3 +/- 1.5 +/- 14.3 +/- mu b for 7 and 13 TeV. The ratio is 2.14 +/- 0.02 +/- 0.13, where the quoted uncertainties are statistical and systematic, respectively. The agreement with theoretical expectation is good at 7 TeV, but differs somewhat at 13 TeV. The measured ratio of cross sections is larger at lower eta than the model prediction.
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