Biagio Di Micco

Measurement of the distributions of event-by-event flow harmonics in Pb+Pb collisions at √sNN = 2.76 TeV with the ATLAS detector

The distributions of event-by-event harmonic flow coefficients vn for n =2–4 are measured in √ sNN = 2.76 TeV Pb+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using charged particles with transverse momentum pT > 0.5 GeV and in the pseudorapidity range |η| < 2.5 in a dataset of approximately 7 μb−1 recorded in 2010. The shapes of the vn distributions are described by a two-dimensional Gaussian function for the underlying flow vector in central collisions for v2 and over most of the measured centrality range for v3 and v4. Significant deviations from this function are observed for v2 in mid-central and peripheral collisions, and a small deviation is observed for v3 in mid-central collisions. It is shown that the commonly used multi-particle cumulants are insensitive to the deviations for v2. The vn distributions are also measured independently for charged particles with 0.5 < pT < 1 GeV and pT > 1 GeV. When these distributions are rescaled to the same mean values, the adjusted shapes are found to be nearly the same for these two pT ranges. The vn distributions are compared with the eccentricity distributions from two models for the initial collision geometry: a Glauber model and a model that includes corrections to the initial geometry due to gluon saturation effects. Both models fail to describe the experimental data consistently over most of the measured centrality range. Prepared for submission to JHEP Measurement of the distributions of event-by-event flow harmonics in lead–lead collisions at √ s NN = 2.76 TeV with the ATLAS detector at the LHC The ATLAS Collaboration Abstract: The distributions of event-by-event harmonic flow coefficients vn for n =2– 4 are measured in √ sNN = 2.76 TeV Pb+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using charged particles with transverse momentum pT > 0.5 GeV and in the pseudorapidity range |η| < 2.5 in a dataset of approximately 7 μb−1 recorded in 2010. The shapes of the vn distributions are described by a twodimensional Gaussian function for the underlying flow vector in central collisions for v2 and over most of the measured centrality range for v3 and v4. Significant deviations from this function are observed for v2 in mid-central and peripheral collisions, and a small deviation is observed for v3 in mid-central collisions. It is shown that the commonly used multi-particle cumulants are insensitive to the deviations for v2. The vn distributions are also measured independently for charged particles with 0.5 < pT < 1 GeV and pT > 1 GeV. When these distributions are rescaled to the same mean values, the adjusted shapes are found to be nearly the same for these two pT ranges. The vn distributions are compared with the eccentricity distributions from two models for the initial collision geometry: a Glauber model and a model that includes corrections to the initial geometry due to gluon saturation effects. Both models fail to describe the experimental data consistently over most of the measured centrality range. The distributions of event-by-event harmonic flow coefficients vn for n =2– 4 are measured in √ sNN = 2.76 TeV Pb+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using charged particles with transverse momentum pT > 0.5 GeV and in the pseudorapidity range |η| < 2.5 in a dataset of approximately 7 μb−1 recorded in 2010. The shapes of the vn distributions are described by a twodimensional Gaussian function for the underlying flow vector in central collisions for v2 and over most of the measured centrality range for v3 and v4. Significant deviations from this function are observed for v2 in mid-central and peripheral collisions, and a small deviation is observed for v3 in mid-central collisions. It is shown that the commonly used multi-particle cumulants are insensitive to the deviations for v2. The vn distributions are also measured independently for charged particles with 0.5 < pT < 1 GeV and pT > 1 GeV. When these distributions are rescaled to the same mean values, the adjusted shapes are found to be nearly the same for these two pT ranges. The vn distributions are compared with the eccentricity distributions from two models for the initial collision geometry: a Glauber model and a model that includes corrections to the initial geometry due to gluon saturation effects. Both models fail to describe the experimental data consistently over most of the measured centrality range.A bstractThe distributions of event-by-event harmonic flow coefficients vn for n = 2- 4 are measured in

Measurement of the K-L ->pi mu nu form factor parameters with the KLOE detector RID C-6238-2011 RID D-2250-2011 RID G-6301-2011 RID C-9722-2011 RID D-2615-2009 RID A-6640-2010

\sqrt{{{s_{NN }}}}

Study of the radiative decay phi to a0(980) gamma with the KLOE detector

= 2.76 TeV Pb + Pb collisions using the ATLAS detector at the LHC. The measurements are performed using charged particles with transverse momentum pT> 0.5 GeV and in the pseudorapidity range |η| < 2.5 in a dataset of approximately 7 μb−1 recorded in 2010. The shapes of the vn distributions suggest that the associated flow vectors are described by a two-dimensional Gaussian function in central collisions for v2 and over most of the measured centrality range for v3 and v4. Significant deviations from this function are observed for v2 in mid-central and peripheral collisions, and a small deviation is observed for v3 in mid-central collisions. In order to be sensitive to these deviations, it is shown that the commonly used multi-particle cumulants, involving four particles or more, need to be measured with a precision better than a few percent. The vn distributions are also measured independently for charged particles with 0.5 < pT< 1 GeV and pT> 1 GeV. When these distributions are rescaled to the same mean values, the adjusted shapes are found to be nearly the same for these two pT ranges. The vn distributions are compared with the eccentricity distributions from two models for the initial collision geometry: a Glauber model and a model that includes corrections to the initial geometry due to gluon saturation effects. Both models fail to describe the experimental data consistently over most of the measured centrality range.

KLOE extraction of

Using 328 pbof data collected at DAΦNE corresponding to ∼1.8 million KL → πμν decays, we have measured the Kμ3 form factor parameters. The structure of the K − π vector-current provides information about the dynamics of the strong interaction; its knowledge is necessary for evaluation of the phase-space integral required for measuring the CKM matrix element Vus and for testing lepton universality in kaon decays. Using a new parametrization for the vector and scalar form factors, we find λ+=(25.7 ± 0.6) × 10 −3 and λ0=(14.0 ± 2.1) × 10 . Our result for λ0, together with recent lattice calculations of fπ, fK and f(0), satisfies the Callan-Treiman relation.Using 328 pb−1 of data collected at DAΦNE corresponding to ~1.8 million KL → πμν decays, we have measured the Kμ3 form factor parameters. The structure of the K−π vector-current provides information about the dynamics of the strong interaction; its knowledge is necessary for evaluation of the phase-space integral required for measuring the CKM matrix element Vus and for testing lepton universality in kaon decays. Using a new parametrization for the vector and scalar form factors, we find λ+ = (25.7 ± 0.6) × 10−3, and λ0 = (14.0 ± 2.1) × 10−3. Our result for λ0, together with recent lattice calculations of fπ, fK and f(0), satisfies the Callan-Treiman relation.