Abstract: We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.

Abstract: We have studied the contribution of the state X(3930), coming from the interaction of the D ($) over bar and D-s(+) D ($) over bar (s) channels, to the B- -> K- J/psi omega decay. The purpose of this work is to offer a complementary tool to see if the X(3930) state observed in the D+ D- channel is the same or not as the X(3960) resonance claimed by the LHCb Collaboration from a peak in the D-s(+) D s mass distribution around threshold. We present results for what we expect in the J/psi omega mass distribution in the B- -> K- J/psi omega decay and conclude that a clear signal should be seen around 3930 MeV. At the same time, finding no extra resonance signal at 3960 MeV would be a clear indication that there is not a new state at 3960 MeV, supporting the hypothesis that the near-threshold peaking structure peak in the D-s(+) D-s(-) mass distribution is only a manifestation of a resonance below threshold.

Abstract: ATLAS measurements of the azimuthal anisotropy in lead-lead collisions at root(NN)-N-S = 2.76 TeV are shown using a dataset of approximately 7 μb(-1) collected at the LHC in 2010. The measurements are performed for charged particles with transverse momenta 0.5 < p(T) < 20 GeV and in the pseudorapidity range vertical bar eta vertical bar < 2.5. The anisotropy is characterized by the Fourier coefficients, vn, of the charged-particle azimuthal angle distribution for n = 2-4. The Fourier coefficients are evaluated using multi-particle cumulants calculated with the generating function method. Results on the transverse momentum, pseudorapidity and centrality dependence of the v(n) coefficients are presented. The elliptic flow, v(2), is obtained from the two-, four-, six-and eight-particle cumulants while higher-order coefficients, v(3) and v(4), are determined with two-and four-particle cumulants. Flow harmonics v(n) measured with four-particle cumulants are significantly reduced compared to the measurement involving two-particle cumulants. A comparison to v(n) measurements obtained using different analysis methods and previously reported by the LHC experiments is also shown. Results of measurements of flow fluctuations evaluated with multiparticle cumulants are shown as a function of transverse momentum and the collision centrality. Models of the initial spatial geometry and its fluctuations fail to describe the flow fluctuations measurements.