Search for a heavy pseudoscalar boson decaying to a Z and a Higgs boson at root s=13TeV

A search is presented for a heavy pseudoscalar boson A decaying to a Z boson and a Higgs boson with mass of 125 GeV. In the final state considered, the Higgs boson decays to a bottom quark and antiquark, and the Z boson decays either into a pair of electrons, muons, or neutrinos. The analysis is performed using a data sample corresponding to an integrated luminosity of 35.9 fb-1 collected in 2016 by the CMS experiment at the LHC from proton-proton collisions at a center-of-mass energy of 13 Te. The data are found to be consistent with the background expectations. Exclusion limits are set in the context of two-Higgs-doublet models in the A boson mass range between 225 and 1000

Correlations of azimuthal anisotropy Fourier harmonics with subevent cumulants in pPb collisions at root s(NN)=8.16 TeV

Event-by-event long-range correlations of azimuthal anisotropy Fourier coefficients (v(n)) in 8.16 TeV pPb data, collected by the CMS experiment at the CERN Large Hadron Collider, are extracted using a subevent four-particle cumulant technique applied to very low multiplicity events. Each combination of four charged particles is selected from either two, three, or four distinct subevent regions of a pseudorapidity range from -2.4 to 2.4 of the CMS tracker, and with transverse momentum between 0.3 and 3.0 GeV. Using the subevent cumulant technique, correlations between v(n) of different orders are measured as functions of particle multiplicity and compared to the standard cumulant method without subevents over a wide event multiplicity range. At high multiplicities, the v(2) and v(3) coefficients exhibit an anticorrelation; this behavior is observed consistently using various methods. The v(2) and v(4) correlation strength is found to depend on the number of subevents used in the calculation. As the event multiplicity decreases, the results from different subevent methods diverge because of different contributions of noncollective or few-particle correlations. Correlations extracted with the four-subevent method exhibit a tendency to diminish monotonically toward the lowest multiplicity region (about 20 charged tracks) investigated. These findings extend previous studies to a significantly lower event multiplicity range and establish the evidence for the onset of long-range collective multiparticle correlations in small system collisions

Performance of missing transverse momentum reconstruction in proton-proton collisions at root s=13 TeV using the CMS detector

The performance of missing transverse momentum ((p) over right arrow (miss)(T)) reconstruction algorithms for the CMS experiment is presented, using proton-proton collisions at a center-of-mass energy of 13 TeV, collected at the CERN LHC in 2016. The data sample corresponds to an integrated luminosity of 35.9 fb(-1). The results include measurements of the scale and resolution of (p) over right arrow (miss)(T), and detailed studies of events identified with anomalous (p) over right arrow (miss)(T). The performance is presented of a (p) over right arrow (miss)(T) reconstruction algorithm that mitigates the effects of multiple proton-proton interactions, using the “pileup per particle identification” method. The performance is shown of an algorithm used to estimate the compatibility of the reconstructed (p) over right arrow (miss)(T) with the hypothesis that it originates from resolution effects

Multiparticle correlations and higher order harmonics in pPb collisions at root s(NN)=8.16 TeV

The elliptic and higher-order azimuthal anisotropy Fourier harmonics (v(n)) are obtained for pPb collisions at root s(NN) = 8.16 TeV over a wide range of event multiplicities based on multiparticle correlations. The data were collected by the CMS experiment during the 2016 LHC run. A sample of peripheral PbPb collisions at root s(NN) = 5.02 TeV covering a similar range of event multiplicities to the pPb results is also analyzed for comparison. The ratios of different harmonic moments are obtained for both v(2) and v(3) with high precision, which allows a direct comparison to theoretical predictions assuming a hydrodynamic evolution of the created medium with initial-state density fluctuations, particularly probing the non-Gaussian nature of initial-state fluctuations in small collision systems. The presented results provide crucial insights into the origin of collective long-range correlations observed in small collision systems

D-0-Meson R-AA in PbPb Collisions at root s(NN)=5.02 TeV and Elliptic Flow in pPb Collisions at root s(NN)=8.16 TeV with CMS

The study of charm production in heavy-ion collisions is considered an excellent probe for the properties of the hot and dense medium created in heavy-ion collisions. Measurements of D-0-meson nuclear modification factor can provide strong constraints into the mechanisms of in-medium energy loss and charm flow in the medium. The measurement of D-0-meson elliptic flow in pPb collisions helps us understand the strength of charm quarks coupling to significantly reduced systems which demonstrate hydrodynamic properties. In this paper, the measurements of the D-0-meson nuclear modification factor in PbPb collisions at 5.02 TeV together with the new measurement of D-0-meson elliptic flow in high multiplicity pPb collisions at 5.02 TeV using the two-particle correlation method will be presented

Beyond nPDFs effects : Prompt J/psi and psi(2S) production in pPb and pp collisions

A multi-dimensional analysis of prompt charmonia in pp and pPb collisions at root s(NN) = 5.02 TeV with the CMS detector is presented. The pPb differential cross-sections of prompt J/psi are shown in a wide kinematic region, for transverse momentum p(T) spanning from 2 to 30 GeV/c and a rapidity interval between -2.4 to 1.93 in the center of mass of the collision. The final results on prompt psi/(2S) meson production cross section in pp and pPb collisions at 5.02 TeV are also reported as a function of p(T) and rapidity, for p(T) from 4 to 30 GeV/c. The nuclear modification factor is found to be smaller than that of prompt J/psi in all measured bins, especially at low p(T) and at backward rapidity. Such a different behaviour between the ground and excited states cannot be reproduced considering nPDF effects alone