T. Grussenmeyer

Multiplicities of charged pions and unidentified charged hadrons from deep-inelastic scattering of muons off an isoscalar target

C. Adolph, J. Agarwala, M. Aghasyan +224

Multiplicities of charged pions and unidentified hadrons produced in deep-inelastic scattering were measured in bins of the Bjorken scaling variable $x$ , the relative virtual-photo…

Exclusive $I ¨ $ meson muoproduction on transversely polarised protons

C. Adolph, J. Agarwala, M. Aghasyan +225

Exclusive production of $I ¨ $ mesons was studied at the COMPASS experiment by scattering $160 GeV / c$ muons off transversely polarised protons. Five single-spin and…

Measurement of the charged-pion polarisability

C. Adolph, R. Akhunzyanov, M. G. Alexeev +210

The COMPASS collaboration at CERN has investigated pion Compton scattering, $I ¨ ^{-} I^^{3} \to I ¨ ^{-} I^^{3}$ , at centre-of-mass energy below 3.5 pion masses. The process is embedded in t…

hep-ex2018

Light isovector resonances in $I ¨ ^{-} p \to I ¨ ^{-} I ¨ ^{-} I ¨ ^{+} p$ at 190 GeV/ $c$

M. Aghasyan, M. G. Alexeev, G. D. Alexeev +221

We have performed the most comprehensive resonance-model fit of $I ¨ ^{-} I ¨ ^{-} I ¨ ^{+}$ states using the results of our previously published partial-wave analysis (PWA) of a large data set…

Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high $p_{T}$

COMPASS Collaboration, C. Adolph, R. Akhunzyanov +207

We measured the longitudinal double spin asymmetries $A_{LL}$ for single hadron muo-production off protons and deuterons at photon virtuality $Q^{2}$ < 1(GeV/ $c$ ) $^{2}$ for transve…

Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised proton

C. Adolph, R. Akhunzyanov, M. G. Alexeev +205

Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off tra…

Search for exclusive photoproduction of Z $_{c}^{\pm}$ (3900) at COMPASS

C. Adolph, R. Akhunzyanov, M. G. Alexeev +205

A search for the exclusive production of the $Z_{c}^{\pm} (3900)$ hadron by virtual photons has been performed in the channel $Z_{c}^{\pm} (3900) \to J / I ¨ I ¨ ^{\pm}$ . The data cover…

First measurement of transverse-spin-dependent azimuthal asymmetries in the Drell-Yan process

Aghasyan, R. Akhunzyanov, M. G. Alexeev +216

The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190 GeV/ $c$ , $I ¨ ^{-}$ beam and…

Sivers asymmetry extracted in SIDIS at the hard scale of the Drell-Yan process at COMPASS

C. Adolph, M. Aghasyan, R. Akhunzyanov +223

Proton transverse-spin azimuthal asymmetries are extracted from the COMPASS 2010 semi-inclusive hadron measurements in deep inelastic muon-nucleon scattering in those four regions…

Resonance Production and $I ¨ I ¨ $ S-wave in $I ¨ ^{-} + p \to I ¨ ^{-} I ¨ ^{-} I ¨ ^{+} + p_{r eco i l}$ at 190 GeV/c

C. Adolph, R. Akhunzyanov, M. G. Alexeev +206

The COMPASS collaboration has collected the currently largest data set on diffractively produced $I ¨ ^{-} I ¨ ^{-} I ¨ ^{+}$ final states using a negative pion beam of 190 GeV/c momentum imping…

The Spin Structure Function $g_{1}^{p}$ of the Proton and a Test of the Bjorken Sum Rule

C. Adolph, R. Akhunzyanov, M. G. Alexeev +203

New results for the double spin asymmetry $A_{1}^{p}$ and the proton longitudinal spin structure function $g_{1}^{p}$ are presented. They were obtained by the COMPASS collabora…

Odd and Even Partial Waves of $I^\cdot I ¨ ^{-}$ and $I^\cdot^{'} I ¨ ^{-}$ in $I ¨ ^{-} p \to I^\cdot^{(')} I ¨ ^{-} p$ at $191 GeV / c$

C. Adolph, R. Akhunzyanov, M. G. Alexeev +205

Exclusive production of $I^\cdot I ¨ ^{-}$ and $I^\cdot^{'} I ¨ ^{-}$ has been studied with a $191 GeV / c$ $I ¨ ^{-}$ beam impinging on a hydrogen target at COMPASS (CERN). Partial-wave analyses rev…

hep-ex2019

Transverse Extension of Partons in the Proton probed by Deeply Virtual Compton Scattering

R. Akhunzyanov, M. G. Alexeev, G. D. Alexeev +223

We report on the first measurement of exclusive single-photon muoproduction on the proton by COMPASS using 160 GeV/ $c$ polarized $I^¼^{+}$ and $I^¼^{-}$ beams of the CERN SPS impinging o…

Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

C. Adolph, M. Aghasyan, R. Akhunzyanov +217

Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive…

Transverse-momentum-dependent Multiplicities of Charged Hadrons in Muon-Deuteron Deep Inelastic Scattering

M. Aghasyan, R. Akhunzyanov, M. G. Alexeev +227

A semi-inclusive measurement of charged hadron multiplicities in deep inelastic muon scattering off an isoscalar target was performed using data collected by the COMPASS Collaborat…

hep-ex2018

Azimuthal asymmetries of charged hadrons produced in high-energy muon scattering off longitudinally polarised deuterons

C. Adolph, M. Aghasyan, R. Akhunzyanov +221

Single hadron azimuthal asymmetries of positive and negative hadrons produced in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined…

Final COMPASS results on the deuteron spin-dependent structure function $g_{1}^{d}$ and the Bjorken sum rule

C. Adolph, M. Aghasyan, R. Akhunzyanov +223

Final results are presented from the inclusive measurement of deep-inelastic polarised-muon scattering on longitudinally polarised deuterons using a $^{6}$ LiD target. The data were t…

Multiplicities of charged kaons from deep-inelastic muon scattering off an isoscalar target

C. Adolph, J. Agarwala, M. Aghasyan +223

Precise measurements of charged-kaon multiplicities in deep inelastic scattering were performed. The results are presented in three-dimensional bins of the Bjorken scaling variable…

Longitudinal double-spin asymmetry $A_{1}^{p}$ and spin-dependent structure function $g_{1}^{p}$ of the proton at small values of $x$ and $Q^{2}$

M. Aghasyan, R. Akhunzyanov, M. G. Alexeev +225

We present a precise measurement of the proton longitudinal double-spin asymmetry $A_{1}^{p}$ and the proton spin-dependent structure function $g_{1}^{p}$ at photon virtualitie…

Spin alignment and violation of the OZI rule in exclusive $I ¨ $ and $I ¨ $ production in pp collisions

C. Adolph, R. Akhunzyanov, M. G. Alexeev +206

Exclusive production of the isoscalar vector mesons $I ¨ $ and $I ¨ $ is measured with a 190 GeV $/ c$ proton beam impinging on a liquid hydrogen target. Cross section ratios are determi…

hep-ex2018

Search for muoproduction of $X (3872)$ at COMPASS and indication of a new state $X (3872)$

M. Aghasyan, R. Akhunzyanov, M. G. Alexeev +224

We have searched for exclusive production of exotic charmonia in the reaction $I^¼^{+} N \to I^¼^{+} (J / I ¨ I ¨ ^{+} I ¨ ^{-}) I ¨ ^{\pm} N^{'}$ using COMPASS data collected with incoming muo…

First measurement of the Sivers asymmetry for gluons from SIDIS data

C. Adolph, M. Aghasyan, R. Akhunzyanov +223

The Sivers function describes the correlation between the transverse spin of a nucleon and the transverse motion of its partons. It was extracted from measurements of the azimuthal…

hep-ph2017

New analysis of $I^\cdot I ¨ $ tensor resonances measured at the COMPASS experiment

A. Jackura, C. Fernandez-Ramirez, M. Mikhasenko +232

We present a new amplitude analysis of the $I^\cdot I ¨ $ $D$ -wave in $I ¨ ^{-} p \to I^\cdot I ¨ ^{-} p$ measured by COMPASS. Employing an analytical model based on the principles of the relativistic $S…

physics.ins-det2014

The COMPASS Setup for Physics with Hadron Beams

Ph. Abbon, C. Adolph, R. Akhunzyanov +228

The main characteristics of the COMPASS experimental setup for physics with hadron beams are described. This setup was designed to perform exclusive measurements of processes with…

Interplay among transversity induced asymmetries in hadron leptoproduction

Compass Collaboration, C. Adolph, R. Akhunzyanov +206

In the fragmentation of a transversely polarized quark several left-right asymmetries are possible for the hadrons in the jet. When only one unpolarized hadron is selected, it exhi…