Search results for "Chromodynamics"
showing 10 items of 1030 documents
Lattice QCD study of the $H$ dibaryon using hexaquark and two-baryon interpolators
2019
Physical review / D 99(7), 074505 (2019). doi:10.1103/PhysRevD.99.074505
Density distributions in the $B$ meson
2016
We report on a two-flavor lattice QCD study of the axial, charge and matter distributions of the $B$ meson and its first radial excitation. As our framework is the static limit of Heavy Quark Effective Theory (HQET), taking their Fourier transform gives access to several form factors at the kinematical point $q^2=0$. Moreover they provide some useful information on the nature of an excited state, i.e. a radial excitation of a quark-antiquark bound state or a multihadron state.
Measurement of the c0 Baryon Lifetime
2018
We report a measurement of the lifetime of the $��_c^0$ baryon using proton-proton collision data at center-of-mass energies of 7 and 8~TeV, corresponding to an integrated luminosity of 3.0 fb$^{-1}$ collected by the LHCb experiment. The sample consists of about 1000 $��_b^-\to��_c^0��^-\bar��_�� X$ signal decays, where the $��_c^0$ baryon is detected in the $pK^-K^-��^+$ final state and $X$ represents possible additional undetected particles in the decay. The $��_c^0$ lifetime is measured to be $��_{��_c^0} = 268\pm24\pm10\pm2$ fs, where the uncertainties are statistical, systematic, and from the uncertainty in the $D^+$ lifetime, respectively. This value is nearly four times larger than, …
Isolated photon production in proton-nucleus collisions at forward rapidity
2018
We calculate isolated photon production at forward rapidities in proton-nucleus collisions in the Color Glass Condensate framework. Our calculation uses dipole cross sections solved from the running coupling Balitsky-Kovchegov equation with an initial condition fit to deep inelastic scattering data. For comparison, we also update the results for the nuclear modification factor for pion production in the same kinematics. We present predictions for future forward RHIC and LHC measurements at $\sqrt{s_{NN}}=200$ GeV and $\sqrt{s_{NN}}=8$ TeV.
Transverse extension of partons in the proton probed in the sea-quark range by measuring the DVCS cross section
2019
Physics letters / B B793, 188-194 (2019). doi:10.1016/j.physletb.2019.04.038
Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at √s = 7 TeV with the ATLAS detector
2011
The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton–proton collisions at a centre-of-mass energy of √s =7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb[superscript −1]. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the ra…
Study of ordered hadron chains with the ATLAS detector
2017
The analysis of the momentum difference between charged hadrons in high-energy proton-proton collisions is performed in order to study coherent particle production. The observed correlation pattern agrees with a model of a helical QCD string fragmenting into a chain of ground-state hadrons. A threshold momentum difference in the production of adjacent pairs of charged hadrons is observed, in agreement with model predictions. The presence of low-mass hadron chains also explains the emergence of charge-combination-dependent two-particle correlations commonly attributed to Bose-Einstein interference. The data sample consists of 190 μb-1 of minimum-bias events collected with proton-proton colli…
Charm-quark fragmentation fractions and production cross section at midrapidity in pp collisions at the LHC
2022
Physical review / D 105(1), L011103 (2022). doi:10.1103/PhysRevD.105.L011103
Three-body forces in the quark model
2008
The constituent quark model has been very useful for the description of many physical properties of baryons, achieving in most cases a fair agreement with the experimental data 1 The model is based on a non relativistic QCD-inspired dynamics including a harmonic oscillator (h.o.) confinement potential and a spin dependent (hyperfine) interaction. The use of Lovelace coordinates p, ~ avoides any problem with the center of mass motion, while the h.o. potential provides a simple basis for ana ly t ica l calculations, which is a very important feature for many applications, like the evaluation of form factors and Meson Exchange Currents 2. On the other hand the h.o. spectrum is too degenerate w…
η−η′(−glue) Mixing from the Chiral Lagrangian
2010
The η − η ′ mixing from the chiral Lagrangian is reviewed. It is shown how the Feldman-Kroll-Stech ansazt can be derived from the chiral Lagrangian. The inclusion of the glueball is also discussed.