We propose a novel approach to measure the branching ratios of the leptonic η(′)→μ+μ− decays by using charmed meson decays, namely, D(s)+→π+η(′)(→μ+μ−) and D0→K−π+η(′)(→μ+μ−). We advocate that the ...data available at LHCb can already yield a new measurement of Br(η→μ+μ−) with accuracy competitive with the current world average. We also estimate that using the data collected by LHCb between 2015 and 2018 in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.0 fb−1, the relative uncertainties to this branching ratio can be reduced down to ∼10%. We also show that the first observation of Br(η′→μ+μ−) may be possible with the upgrade of the LHCb experiment.
The electron-positron collider DA Phi NE, the Italian Phi factory, has been recently upgraded in order to implement an innovative collision scheme based on large crossing angle, small beam sizes at ...the crossing point, and compensation of beam-beam interaction by means of sextupole pairs creating a "crab-waist" configuration in the interaction region. Experimental tests of the novel scheme exhibited an increase by a factor of 3 in the peak luminosity of the collider with respect to the performances reached before the upgrade. In this Letter we present the new collision scheme, discuss its advantages, describe the hardware modifications realized for the upgrade, and report the results of the experimental tests carried out during commissioning of the machine in the new configuration and standard operation for the users.
Detectors for absolute luminosity measurement at DAFNE Valente, P.; Boscolo, M.; Bossi, F. ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
05/2010, Volume:
617, Issue:
1
Journal Article, Conference Proceeding
Peer reviewed
Open access
Since the second half of year 2007, the Frascati
Φ
- factory DAFNE has been running with an upgraded interaction region in order to test the crabbed waist collision scheme. The aim is to reach a ...large improvement of the specific luminosity of the accelerator. We describe the various detectors realized to have a reliable and fast absolute luminosity measurement, the on-line analysis in order to get rid of the machine background contribution, and the performances of the system.
This paper describes the LUMI project which aims at providing fast, reliable and absolute luminosity measurements at the modified DAφNE interaction point in Frascati for testing the new "crabbed ...waist" scheme. We present a description of the experimental setup (two luminometers, LUMI1 and LUMI2), the simulation framework developped for this project and summarize the results and performances.
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