New developments in measurements of CP violation

We present several alternative techniques used by the BaBar Collaboration in order to measure the Unitarity Triangle angle gamma. We also present the results of two searches designed to improve the measurements of sin(2beta) using penguin B decay modes by reducing the hadronic corrections uncertainties.Comment: 6 pages, 4 figures, Contribution to Moriond ElectroWeak 2006 Proceeding

Measurement of Inclusive W and Z Boson Production Cross Sections in pp Collisions at s√=8 TeV

A measurement of total and fiducial inclusive W and Z boson production cross sections in pp collisions at s√=8  TeV is presented. Electron and muon final states are analyzed in a data sample collected with the CMS detector corresponding to an integrated luminosity of 18.2±0.5  pb−1. The measured total inclusive cross sections times branching fractions are σ(pp→WX)×B(W→ℓν)=12.21±0.03(stat)±0.24(syst)±0.32(lum)  nb and σ(pp→ZX)×B(Z→ℓ+ℓ−)=1.15±0.01(stat)±0.02(syst)±0.03(lum)  nb for the dilepton mass in the range of 60—120 GeV. The measured values agree with next-to-next-to-leading-order QCD cross section calculations. Ratios of cross sections are reported with a precision of 2%. This is the first measurement of inclusive W and Z boson production in proton-proton collisions at s√=8  TeV

Differential cross section measurements for the production of a W boson in association with jets in proton–proton collisions at s√=7 TeV

Measurements are reported of differential cross sections for the production of a W boson, which decays into a muon and a neutrino, in association with jets, as a function of several variables, including the transverse momenta (pTpT) and pseudorapidities of the four leading jets, the scalar sum of jet transverse momenta (HTHT), and the difference in azimuthal angle between the directions of each jet and the muon. The data sample of pp collisions at a centre-of-mass energy of 7 TeV was collected with the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb−1. The measured cross sections are compared to predictions from Monte Carlo generators, MadGraph + pythia and sherpa, and to next-to-leading-order calculations from BlackHat + sherpa. The differential cross sections are found to be in agreement with the predictions, apart from the pTpT distributions of the leading jets at high pTpT values, the distributions of the HTHT at high-HTHT and low jet multiplicity, and the distribution of the difference in azimuthal angle between the leading jet and the muon at low values.Funded by SCOAP

Measurement of pseudorapidity distributions of charged particles in proton–proton collisions at s√=8 TeV by the CMS and TOTEM experiments

This is the published version.Pseudorapidity (η) distributions of charged particles produced in proton–proton collisions at a centre-of-mass energy of 8 TeV are measured in the ranges |η|<2.2 and 5.3<|η|<6.4 covered by the CMS and TOTEM detectors, respectively. The data correspond to an integrated luminosity of L=45 μb−1. Measurements are presented for three event categories. The most inclusive category is sensitive to 91–96 % of the total inelastic proton–proton cross section. The other two categories are disjoint subsets of the inclusive sample that are either enhanced or depleted in single diffractive dissociation events. The data are compared to models used to describe high-energy hadronic interactions. None of the models considered provide a consistent description of the measured distributions

Measurement of the hadronic activity in events with a Z and two jets and extraction of the cross section for the electroweak production of a Z with two jets in pp collisions at s√=7 TeV

This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP10%282013%29062.The first measurement of the electroweak production cross section of a Z boson with two jets (Zjj) in pp collisions at s√=7 TeV is presented, based on a data sample recorded by the CMS experiment at the LHC with an integrated luminosity of 5 fb(−1). The cross section is measured for the ℓℓjj (ℓ = e, μ) final state in the kinematic region m(ℓℓ) > 50 GeV, m(jj) > 120 GeV, transverse momenta p(j)(T)>25 GeV and pseudorapidity |η(j)| < 4.0. The measurement, combining the muon and electron channels, yields σ = 154 ± 24 (stat.) ± 46 (exp. syst.) ± 27 (th. syst.) ± 3 (lum.) fb, in agreement with the theoretical cross section. The hadronic activity, in the rapidity interval between the jets, is also measured. These results establish an important foundation for the more general study of vector boson fusion processes, of relevance for Higgs boson searches and for measurements of electroweak gauge couplings and vector boson scattering

Inclusive b-hadron production cross section with muons in pp collisions at s√=7TeV

A measurement of the b-hadron production cross section in proton-proton collisions at s√=7TeVs=7TeV is presented. The dataset, corresponding to 85 nb−1, was recorded with the CMS experiment at the LHC using a low-threshold single-muon trigger. Events are selected by the presence of a muon with transverse momentum pμT>6GeVpTμ>6GeV with respect to the beam direction and pseudorapidity |η μ | < 2.1. The transverse momentum of the muon with respect to the closest jet discriminates events containing b hadrons from background. The inclusive b-hadron production cross section is presented as a function of muon transverse momentum and pseudorapidity. The measured total cross section in the kinematic acceptance is σ(pp → b + X → μ + X′) = 1.32 ± 0.01(stat) ± 0.30(syst) ± 0.15(lumi)μb

Measurement of the Λ(0)(b) lifetime in pp collisions at s√=7 TeV

This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP07%282013%29163.A measurement of the Λ(0)(b) lifetime using the decay Λ(0)(b)→J/ψΛ in protonproton collisions at s√=7 TeV is presented. The data set, corresponding to an integrated luminosity of about 5 fb(−1), was recorded with the CMS experiment at the Large Hadron Collider using triggers that selected dimuon events in the J/ψ mass region. The Λ(0)(b) lifetime is measured to be 1.503 ± 0.052 (stat.) ± 0.031 (syst.) ps

Transverse-momentum and pseudorapidity distributions of charged hadrons in pp collisions at s√=0.9 and 2.36 TeV

This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP02%282010%29041.Measurements of inclusive charged-hadron transverse-momentum and pseudorapidity distributions are presented for proton-proton collisions at s√=0.9 and 2.36 TeV. The data were collected with the CMS detector during the LHC commissioning in December 2009. For non-single-diffractive interactions, the average charged-hadron transverse momentum is measured to be 0.46 ± 0.01 (stat.) ± 0.01 (syst.) GeV/c at 0.9 TeV and 0.50 ± 0.01 (stat.) ± 0.01 (syst.) GeV/c at 2.36 TeV, for pseudorapidities between --2.4 and +2.4. At these energies, the measured pseudorapidity densities in the central region, dN (ch)/dη|(|η|)<0.5, are 3:48 ± 0:02 (stat.) ± 0.13 (syst.) and 4:47 ± 0:04 (stat.) ± 0.16 (syst.), respectively. The results at 0.9 TeV are in agreement with previous measurements and confirm the expectation of near equal hadron production in p-bar p and pp collisions. The results at 2.36 TeV represent the highest-energy measurements at a particle collider to date

Observation of long-range, near-side angular correlations in proton-proton collisions at the LHC

This is the publisher's version, also available electronically from http://link.springer.com/article/10.1007%2FJHEP09%282010%29091.Results on two-particle angular correlations for charged particles emitted in proton-proton collisions at center-of-mass energies of 0.9, 2.36, and 7 TeV are presented, using data collected with the CMS detector over a broad range of pseudorapidity (η) and azimuthal angle (ϕ). Short-range correlations in Δη, which are studied in minimum bias events, are characterized using a simple “independent cluster” parametrization in order to quantify their strength (cluster size) and their extent in η (cluster decay width). Long-range azimuthal correlations are studied differentially as a function of charged particle multiplicity and particle transverse momentum using a 980 nb(−1) data set at 7 TeV. In high multiplicity events, a pronounced structure emerges in the two-dimensional correlation function for particle pairs with intermediate p T of 1–3 GeV/c, 2.0 < |Δη| < 4.8 and Δϕ ≈ 0. This is the first observation of such a long-range, near-side feature in two-particle correlation functions in pp or pp-bar collisions

Search for Dijet Resonances in 7 TeV pp Collisions at CMS

This is the publisher's version, also available electronically from http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.105.211801.A search for narrow resonances in the dijet mass spectrum is performed using data corresponding to an integrated luminosity of 2.9  pb(−1) collected by the CMS experiment at the Large Hadron Collider. Upper limits at the 95% confidence level are presented on the product of the resonance cross section, branching fraction into dijets, and acceptance, separately for decays into quark-quark, quark-gluon, or gluon-gluon pairs. The data exclude new particles predicted in the following models at the 95% confidence level: string resonances, with mass less than 2.50 TeV, excited quarks, with mass less than 1.58 TeV, and axigluons, colorons, and E6 diquarks, in specific mass intervals. This extends previously published limits on these models