An angular analysis of the $B^{0}\rightarrow K^{*0}(\rightarrow K^{+}\pi^{-})\mu^{+}\mu^{-}$ decay is presented. The dataset corresponds to an integrated luminosity of $3.0\,{\mbox{fb}^{-1}}$ of $pp$ collision data collected at the LHCb experiment. The complete angular information from the decay is used to determine $C\!P$-averaged observables and $C\!P$ asymmetries, taking account of possible contamination from decays with the $K^{+}\pi^{-}$ system in an S-wave configuration. The angular observables and their correlations are reported in bins of $q^2$, the invariant mass squared of the dimuon system. The observables are determined both from an unbinned maximum likelihood fit and by using the principal moments of the angular distribution. In addition, by fitting for $q^2$-dependent decay amplitudes in the region $1.1
CP-averaged angular observables evaluated by the unbinned maximum likelihood fit.
CP-averaged angular observables evaluated by the unbinned maximum likelihood fit. The first uncertainties are statistical and the second systematic.
CP-asymmetric angular observables evaluated by the unbinned maximum likelihood fit. The first uncertainties are statistical and the second systematic.
Jet substructure quantities are measured using jets groomed with the soft-drop grooming procedure in dijet events from 32.9 fb$^{-1}$ of $pp$ collisions collected with the ATLAS detector at $\sqrt{s} = 13$ TeV. These observables are sensitive to a wide range of QCD phenomena. Some observables, such as the jet mass and opening angle between the two subjets which pass the soft-drop condition, can be described by a high-order (resummed) series in the strong coupling constant $\alpha_S$. Other observables, such as the momentum sharing between the two subjets, are nearly independent of $\alpha_S$. These observables can be constructed using all interacting particles or using only charged particles reconstructed in the inner tracking detectors. Track-based versions of these observables are not collinear safe, but are measured more precisely, and universal non-perturbative functions can absorb the collinear singularities. The unfolded data are directly compared with QCD calculations and hadron-level Monte Carlo simulations. The measurements are performed in different pseudorapidity regions, which are then used to extract quark and gluon jet shapes using the predicted quark and gluon fractions in each region. All of the parton shower and analytical calculations provide an excellent description of the data in most regions of phase space.
Data from Fig 6a. The unfolded all-particle $log_{10}(\rho^2)$ distribution for anti-kt R=0.8 jets with $p_T$ > 300 GeV, after the soft drop algorithm is applied for $\beta$ = 0, in data. All uncertainties described in the text are shown on the data. The distributions are normalized to the integrated cross section, $\sigma$(resum), measured in the resummation region, $-3.7 < log_{10}(\rho^2) < -1.7$.
Data from Fig 6b. The unfolded charged-particle $log_{10}(\rho^2)$ distribution for anti-kt R=0.8 jets with $p_T$ > 300 GeV, after the soft drop algorithm is applied for $\beta$ = 0, in data. All uncertainties described in the text are shown on the data. The distributions are normalized to the integrated cross section, $\sigma$(resum), measured in the resummation region, $-3.7 < log_{10}(\rho^2) < -1.7$.
Data from Fig 6c. The unfolded all-particle $log_{10}(\rho^2)$ distribution for anti-kt R=0.8 jets with $p_T$ > 300 GeV, after the soft drop algorithm is applied for $\beta$ = 1, in data. All uncertainties described in the text are shown on the data. The distributions are normalized to the integrated cross section, $\sigma$(resum), measured in the resummation region, $-3.7 < log_{10}(\rho^2) < -1.7$.
Antilambda production is studied inK−p interactions at 32 GeV/c. Both total and differential cross sections are presented. The inclusive\(\bar \Lambda \) production cross section amounts to 109±7 μb. A remarkable energy dependence is observed, σ(\(\bar \Lambda \)) increasing by a factor of four between 14.3 and 32 GeV/c. Thep⊥2 distribution exhibits an exponential fall-off with a slope of 3.3±0.2 (GeV/c)−2. Most of the\(\bar \Lambda \)'s are emitted in the forward hemisphere. The invariantx distribution increases between 14.3 and 32 GeV/c. Data are presented for\(\bar \Lambda \) production inK-p→Λ\(\bar \Lambda \)+XK-p→\(\bar \Lambda \)Kn+X, andK-p→\(\bar \Lambda \)p+X.
No description provided.
The production of ρ 0 (770) and f(1270) is studied in π − p interactions at 16 GeV/ c . By comparison with inclusive K ∗0 production in the reaction K − p → K ∗0 + anything, and with inclusive ρ 0 production in the reaction pp → ρ 0 + anything, it is found that the data can be interpreted in terms of two production processes: the central production of resonances and the fragmentation of the beam particle. For the π − p reaction, the inclusive ρ 0 beam fragmentation cross section is 3.1 ± 0.3 mb while that for central production is 1.6 ± 0.5 mb. The ρ 0 central production cross section is consistent with increasing with energy as ln s behaviour. The ratio of ρ 0 to π − inclusive cross sections (excluding the leading π − ) is ∼0.2, independent of energy. The ρ 0 to π − ratio increases as a function of p T to a constant value of ∼ 1 2 above 1 GeV/ c . The ρ (charged and neutral) and f decays account for (25 ± 4)% and (1.4 ± 0.3)%, respectively, of all pions produced.
No description provided.
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By means of an isospin analysis of the reaction π ± p→ π (N π ) at 16 GeV/ c we have determined the decay angular distributions of the N π system with I= 1 2 produced by isospin zero exchange. Helicity conservation is not observed in the t -channel for the N π mass region below 1.6 GeV, where diffraction dissociation of the proton is supposed to dominate. There are indications for approximate t -channel helicity conservation for N ∗ (1690) production. In the helicity frame, the experimental data are not in agreement with s -channel helicity conservation over the whole N π mass range investigated. Thus the diffractive process N→N π differs both from the process N→N ππ (or π → πππ and K→K ππ ) which approximately conserves t -channel helicity and from the elastic scattering N→N which conserves helicity in the s -channel.
No description provided.
FIT TO ISOSPIN HALF NUCLEON RESONANCE PRODUCTION WITH ISOSPIN ZERO EXCHANGE.
In a K − p experiment at 32 GeV/ c with a sensitivity of 6 ev/≈b the inclusive reaction K − p → p + X was studied in the kinematical region x < −0.3. Most of the protons in this region were identified by ionization. Correcting for losses of the very slow as well as of the fast protons in this region we obtained σ p ( x < −0.3) = 5.9 ± 0.2 mb. The double invariant differential cross sections of protons were analysed in terms of the variables x , p T 2 , and M 2 / s , t , and the contributions from separate peripheral mechanisms were analysed. A triple-Regge analysis was performed on the inclusive proton d 2 σ /d t d( M 2 / s ) distribution with | t | < 1.1 GeV 2 . The fit with an RRP term resulted in an effective trajectory for the exchanged reggeon lying somewhat lower than that for the leading meson trajectory. Inclusion in the fit of an additional ππp term showed that pion exchange is important in the triple-Regge region at small | t |.
No description provided.
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We have studied inclusiveΔ++ (1232),∑+ (1385), and∑− (1385) baryon resonance production inK−p interactions at 32 GeV/c. The inclusive and topological cross sections are estimated and compared with published results at lower energies. No energy variation of the cross section is observed forΔ++ (1232) and only a slight decrease is seen in case of∑± (1385). The production properties are investigated through longitudinal and transverse momentum distributions. TheΔ++ (1232) is dominantly produced in the target fragmentation region. The∑+ (1385) is produced both in the target fragmentation region and in the central region, while the∑− (1385) is predominantly produced in the central region. About 20% of the final state protons are produced via aΔ++ (1232) decay and about 25% of the Λ produced come from the decay of∑+ (1385) and∑− (1385).
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292+-7 MUB - CORRECTED VALUE FOR FIRST REACTION (SLOW PROTONS). M(P 4PI) <= 3.5 GEV FOR REACTIONS WITH FOUR PIONS.
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This paper presents cross sections for the production of a W boson in association with jets, measured in proton--proton collisions at $\sqrt{s}=7$ TeV with the ATLAS experiment at the Large Hadron Collider. With an integrated luminosity of $4.6 fb^{-1}$, this data set allows for an exploration of a large kinematic range, including jet production up to a transverse momentum of 1 TeV and multiplicities up to seven associated jets. The production cross sections for W bosons are measured in both the electron and muon decay channels. Differential cross sections for many observables are also presented including measurements of the jet observables such as the rapidities and the transverse momenta as well as measurements of event observables such as the scalar sums of the transverse momenta of the jets. The measurements are compared to numerous QCD predictions including next-to-leading-order perturbative calculations, resummation calculations and Monte Carlo generators.
Distribution of inclusive jet multiplicity.
Breakdown of systematic uncertainties in percent in inclusive jet multiplicity in the electron channel.Uncertainties have been symmetrised and the sign denotes the sign of the original up-variation.
Breakdown of systematic uncertainties in percent in inclusive jet multiplicity in the muon channel.Uncertainties have been symmetrised and the sign denotes the sign of the original up-variation.
Event-shape observables measured using charged particles in inclusive $Z$-boson events are presented, using the electron and muon decay modes of the $Z$ bosons. The measurements are based on an integrated luminosity of $1.1 {\rm fb}^{-1}$ of proton--proton collisions recorded by the ATLAS detector at the LHC at a centre-of-mass energy $\sqrt{s}=7$ TeV. Charged-particle distributions, excluding the lepton--antilepton pair from the $Z$-boson decay, are measured in different ranges of transverse momentum of the $Z$ boson. Distributions include multiplicity, scalar sum of transverse momenta, beam thrust, transverse thrust, spherocity, and $\mathcal{F}$-parameter, which are in particular sensitive to properties of the underlying event at small values of the $Z$-boson transverse momentum. The Sherpa event generator shows larger deviations from the measured observables than Pythia8 and Herwig7. Typically, all three Monte Carlo generators provide predictions that are in better agreement with the data at high $Z$-boson transverse momenta than at low $Z$-boson transverse momenta and for the observables that are less sensitive to the number of charged particles in the event.
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