The production of a Z boson provides a clean handle to control the population of events to be studied. By selecting muonic decays of Z bosons, we can isolate the effect of the recoiling process without potential bias from requiring isolation, as is the case for photons. Di-hadron correlations can naturally separate effects from different angular scales. Similar to the energy-energy correlator...
This talk presents recent studies of event-wise mean transverse momentum, [pT] that can help differentiate the interplay between the effect of radial collectivity, random thermal motion and deformation in nuclear geometry. In addition, the Pearson Correlation Coefficient (PCC) between flow, vn and [pT] , ρ(vn, [pT]), will be shown. The results bear on aspects of the initial state, such as...
Heavy-ion collisions produce a hot, dense medium, and high-momentum par- tons from the collision traverse this medium while losing energy in it. Because of the initial geometry of the QGP, partons produced at different angles, with respect to the impact parameter, traverse different path lengths in the medium leading to azimuthal-angle dependence of the yields of high transverse momen- tum...
Leveraging on the injection of noble gases into the LHC accelerator beam-
pipe, LHCb has been collecting since 2015 proton- and lead-gas collisions, which
give access to the poorly explored high-x and moderate Q2 kinematic region. In
particular, studies of strangeness production provides information on hadroniza-
tion and serve as important inputs to models of particle production in...
Measurements of the light-by-light scattering (LbL, $\gamma\gamma\to\gamma\gamma$) and the Breit--Wheeler (B--W, $\gamma\gamma\to\mathrm{e}^+\mathrm{e}^-$) processes are reported in ultraperipheral collisions at 5.02 TeV using the 2018 CMS lead-lead data sample of $1.65~\mathrm{nb}^{-1}$. Events with a pair of exclusively produced photons or electrons are selected, each with transverse energy...
Measurements of the anomalous magnetic moment of leptons are good handles for precision tests of the Standard Model and hints of physics beyond the Standard Model. These measurements for electrons and muons are among the most precisely measured quantities in physics. However, due to the short lifetime of the tau lepton, its anomalous magnetic moment is not as precisely known and needs to be...
The study of the produced hot and dense matter formed in heavy-ion collisions at the LHC allows the characterization of the quark--gluon plasma (QGP), the deconfined state of quarks and gluons. The measurement of the ratio of yields of charged particles in central to peripheral heavy-ion collisions ($I_{\rm{CP}}$) provides strong constraints on the quenching mechanism in the QGP. In this talk,...