Browsing by Author "Leonardo, Nuno T."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Review of bottomonium measurements from CMSPublication . Hu, Z.; Leonardo, Nuno T.; Liu, T.; Haytmyradov, M.We review the results on the bottomonium system from the CMS experiment at the Large Hadron Collider. Measurements have been carried out at different center-of-mass energies in proton collisions and in collisions involving heavy ions. These include precision measurements of cross sections and polarizations, shedding light on hadroproduction mechanisms, and the observation of quarkonium sequential suppression, a notable indication of quark–gluon plasma formation. The observation of the production of bottomonium pairs is also reported along with searches for new states. We close with a brief outlook of the future physics program.
- Search and measurement of the B → μμ rare processes with LHC Run I dataPublication . Leonardo, Nuno T.The decays Bs0→μ+μ− and B0→μ+μ− are highly suppressed in the standard model constituting sensitive probes of new physics. We present the results of a search for these rare decays in proton-proton collisions using the full data sample collected by the CMS experiment during LHC Run I. Through a fit to the dimuon invariant-mass spectrum, an excess of events with respect to the background is observed, compatible with the Bs0(B0) signal with a significance of 4.3 (2.0) standard deviations ( σ ). The measured branching fractions are B(Bs0→μ+μ−)=(3.0−0.9+1.0)×10−9 and B(B0→μ+μ−)=(3.5−1.8+2.1)×10−10 . The combination of the CMS and LHCb results, using their full Run I data samples, yield an event excess compatible with the Bs0(B0) signal with a significance in excess of 6σ(3σ) . The ongoing and projected accelerator and detector upgrades will allow to establish and to carry out precision measurements of both rare decays, and explore novel observables with further sensitivity to new physics effects.
- Search for Resonances and New PhysicsPublication . Leonardo, Nuno T.\noindent The appearance of new resonances is a most spectacular means by which physics beyond the standard model may be revealed at the LHC. Searches are conducted for bumps in mass spectra exploring a multitude of final states. Results are presented spanning from sub-GeV to multi-TeV scales.