COMPASS Conference Proceedings

Derniers ajouts:
2019-01-18
08:13
 Measurement of azimuthal asymmetries in SIDIS on unpolarized protons / Moretti, Andrea (INFN, Trieste ; Trieste U.) The COMPASS Collaboration is measuring the asymmetries in the azimuthal distributions of positive and negative hadrons produced in Deep Inelastic Scattering (DIS) on unpolarized protons. [...] arXiv:1901.01773. - 7 p. Fulltext

2017-12-08
07:26
 Muoproduction of exotic charmonia at COMPASS / Guskov, A. (Dubna, JINR) /COMPASS Collaboration Exotic charmonium-like states have been targeted by various experiments in the last 15 years, but their nature still is unknown. Photo-(muo)production is a new promising instrument to study them. [...] arXiv:1712.01345.- SISSA, 2017-11-27 - 5 p. - Published in : PoS Hadron2017 (2018) 125 Fulltext: PDF; Preprint: PDF; External link: PoS server In : XVII International Conference on Hadron Spectroscopy and Structure, Salamanca, Spain, 25 - 29 Sep 2017, pp.125

2017-12-08
07:26
 First results from an extended freed-isobar analysis at COMPASS / Krinner, Fabian Michael (Munich, Tech. U.) /COMPASS Collaboration One of the goals of the COMPASS experiment is the precision study of light-meson spectroscopy with data for various final states. With $46\times10^6$ exclusive events, the process $\pi^- p\to\pi^-\pi^+\pi^- p$ constitutes the flagship channel. [...] arXiv:1711.10828.- SISSA, 2017-11-30 - 6 p. - Published in : PoS Hadron2017 (2018) 034 Fulltext: PoS(Hadron2017)034 - PDF; 1711.10828 - PDF; Preprint: PDF; External link: PoS server In : XVII International Conference on Hadron Spectroscopy and Structure, Salamanca, Spain, 25 - 29 Sep 2017, pp.034

2017-12-01
07:57
 Recent Results on Light-Meson Spectroscopy from COMPASS / Wallner, Stefan (Munich, Tech. U.) /COMPASS Collaboration The main goal of the spectroscopy program at COMPASS is to explore the light-meson spectrum below about $2\,\text{GeV}/c^2$ in diffractive production. Our flagship channel is the decay into three charged pions: $p + \pi^-\to \pi^-\pi^-\pi^+ + p_\text{recoil}$, for which COMPASS has acquired the so far world's largest dataset of roughly $50\,\text{M}$ exclusive events using an $190\,\text{GeV}/c$ $\pi^-$ beam. [...] arXiv:1711.09782.- SISSA, 2017-11-27 - 7 p. - Published in : PoS Hadron2017 (2018) 032 Fulltext: PDF; Preprint: PDF; External link: PoS server In : XVII International Conference on Hadron Spectroscopy and Structure, Salamanca, Spain, 25 - 29 Sep 2017, pp.032

2017-02-25
07:55
 The $t$-dependence of the pure DVCS cross section at COMPASS / Joerg, Philipp (Freiburg U.) /COMPASS Collaboration The key reactions to study the Generalised Parton Distributions are Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP). At COMPASS, these processes are investigated using a high intensity muon beam with a momentum of 160\,GeV/c and a 2.5\,m-long liquid hydrogen target. [...] arXiv:1702.06315.- SISSA, 2016-10-10 - 7 p. - Published in : PoS: DIS2016 (2016) , pp. 235 Fulltext: PDF; Preprint: PDF; External links: PoS server; 00007 COMPASS results for the t-slope parameter (\textbf{left}) and the extracted transverse size of the partonic distribution of the nucleon (\textbf{right}), compared with previous HERA measurements.; 00003 Exclusivity variables: The whole Monte Carlo estimate is shown in red while in grey only the $\pi^0$ contamination is shown. The variables $\Delta \varphi$, $\Delta p_{\bot}$ and $M_X^2$ are defined in equation \ref{eq_phi}-\ref{eq_m} while $\Delta z_{A}$ encodes a reverse vertex pointing. The blue dotted lines indicate the applied cuts.; 00006 COMPASS results for the t-slope parameter (\textbf{left}) and the extracted transverse size of the partonic distribution of the nucleon (\textbf{right}), compared with previous HERA measurements.; 00001 Exclusivity variables: The whole Monte Carlo estimate is shown in red while in grey only the $\pi^0$ contamination is shown. The variables $\Delta \varphi$, $\Delta p_{\bot}$ and $M_X^2$ are defined in equation \ref{eq_phi}-\ref{eq_m} while $\Delta z_{A}$ encodes a reverse vertex pointing. The blue dotted lines indicate the applied cuts.; 00002 Exclusivity variables: The whole Monte Carlo estimate is shown in red while in grey only the $\pi^0$ contamination is shown. The variables $\Delta \varphi$, $\Delta p_{\bot}$ and $M_X^2$ are defined in equation \ref{eq_phi}-\ref{eq_m} while $\Delta z_{A}$ encodes a reverse vertex pointing. The blue dotted lines indicate the applied cuts.; 00000 Exclusivity variables: The whole Monte Carlo estimate is shown in red while in grey only the $\pi^0$ contamination is shown. The variables $\Delta \varphi$, $\Delta p_{\bot}$ and $M_X^2$ are defined in equation \ref{eq_phi}-\ref{eq_m} while $\Delta z_{A}$ encodes a reverse vertex pointing. The blue dotted lines indicate the applied cuts.; 00005 The $t$-differential DVCS cross section as a function of $t$; 00004 Acceptance correction factors as a function of $t$, $Q^2$ and $\nu$.; Fulltext In : 24th International Workshop on Deep Inelastic Scattering and related subjects, Hamburg, Germany, 11 - 15 Apr 2016, pp.235

2017-02-25
07:55
 Measurement of the exclusive ${\pi}^0$ muoproduction cross section at COMPASS / Gorzellik, Matthias (Freiburg U.) At COMPASS DVCS and DVMP processes are studied in order to probe the partonic structure of the nucleon by constraining GPD models. [...] arXiv:1702.06293. - 4 p. Preprint

2017-02-10
07:37
 COMPASS measurement of the $P_T$ weighted Sivers asymmetry / Bradamante, Franco (INFN, Trieste) The SIDIS transverse spin asymmetries weighted with powers of $P_T$, the hadron transverse momentum in the $\gamma N$ reference system,have been introduced already twenty years ago and are considered quite interesting. [...] arXiv:1702.00621. - 4 p. Preprint

2016-10-08
07:48
 The spectrum of light isovector mesons with $C=+1$ from the COMPASS experiment / Paul, Stephan (Munich, Tech. U.) Based on the largest event sample of diffractively produced $\pi^-\pi^-\pi^+$, obtained by a pion beam of $190~\rm{GeV/c}$ momentum, the COMPASS collaboration has performed the most advanced partial wave analysis on multi-body final states, using the isobar model. The large number of waves included in the analysis reduces truncation effects. [...] arXiv:1610.01231.- 2017 - 9 p. - Published in : JPS Conf. Proc. 13 (2017) 010018 Preprint: PDF; External link: Fulltext In : Meson-Nucleon Physics and the Structure of the Nucleon, Kyoto, Japan, 25 - 30 Jul 2016, pp.010018

2016-09-29
01:12
 Photons interacting with Hadrons at COMPASS / Friedrich, Jan Michael (Technische Universitaet Muenchen (DE)) /COMPASS NA58 Collaboration COMPASS is a multi-purpose experiment operated at CERN for investigations of the strong interaction from low to medium energy scales. At low energies, photon-pion interactions provide input for understanding the effective dynamics of strongly bound states of quarks and gluons, most prominently the recent measurement of the polarisability of the charged pion. [...] COMPASS-PROC-2016-001.- Geneva : CERN, 2015 - 8. Fulltext: PDF;

2016-09-28
07:58
 Extraction of the $\pi^+\pi^-$ Subsystem in Diffractively Produced $\pi^-\pi^+\pi^-$ at COMPASS / Krinner, Fabian (Munich, Tech. U.) /for the COMPASS collaboration The COMPASS experiment at CERN has collected a large data sample of 50 million diffractively produced $\pi^-\pi^+\pi^-$ events using a $190\,$GeV$/c$ negatively charged hadron beam. The partial-wave analysis (PWA) of these high-precision data reveals previously unseen details. [...] arXiv:1609.08514.- 2017 - 5 p. - Published in : JPS Conf.Proc. 13 (2017) 020028 Preprint: PDF; External link: Fulltext In : Meson-Nucleon Physics and the Structure of the Nucleon, Kyoto, Japan, 25 - 30 Jul 2016, pp.020028