R. Jahn

Transverse target spin asymmetries in exclusive $I ¨ ^{0}$ muoproduction

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +209

Exclusive production of $I ¨ ^{0}$ mesons was studied at the COMPASS experiment by scattering 160 GeV/ $c$ muons off transversely polarised protons. Five single-spin and three double-sp…

Measurement of the Cross Section for High-p_T Hadron Production in Scattering of 160 GeV/c Muons off Nucleons

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +209

The differential cross section for production of charged hadrons with high transverse momenta in scattering of 160\,GeV/ $c$ muons off nucleons at low photon virtualities has been m…

hep-ex2017

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…

Study of Î£(1385) and Î(1321) hyperon and antihyperon production in deep inelastic muon scattering

C. Adolph, M. Alekseev, V. Yu. Alexakhin +203

Large samples of Î, Î£(1385) and Î(1321) hyperons produced in deep-inelastic muon scattering off a ^6LiD target were collected with the COMPASS experimental setup at CERN. The re…

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…

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…

nucl-ex2010

High resolution study of the Lambda p final state interaction in the reaction p + p -> K+ + (Lambda p)

A. Budzanowski, A. Chatterjee, H. Clement +26

The reaction pp -> K+ + (Lambda p) was measured at Tp=1.953 GeV and Theta = 0 deg with a high missing mass resolution in order to study the Lambda p final state interaction. The la…

Measurement of azimuthal hadron asymmetries in semi-inclusive deep inelastic scattering off unpolarised nucleons

C. Adolph, R. Akhunzyanov, M. G. Alekseev +217

Spin-averaged asymmetries in the azimuthal distributions of positive and negative hadrons produced in deep inelastic scattering were measured using the CERN SPS muon beam at $160$ …

Experimental investigation of transverse spin asymmetries in muon-p SIDIS processes: Sivers asymmetries

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +215

The COMPASS Collaboration at CERN has measured the transverse spin azimuthal asymmetry of charged hadrons produced in semi-inclusive deep inelastic scattering using a 160 GeV posit…

A high-statistics measurement of transverse spin effects in dihadron production from muon-proton semi-inclusive deep-inelastic scattering

C. Adolph, R. Akhunzyanov, M. G. Alekseev +217

A measurement of the azimuthal asymmetry in dihadron production in deep-inelastic scattering of muons on transversely polarised proton (NH $_{3}$ ) targets are presented. They provid…

hep-ex2017

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…

hep-ex2005

A precision determination of the mass of the $I^\cdot$ meson

The GEM collaboration, M. Abdel-Bary, A. Budzanowski +31

Several processes of meson production in proton-deuteron collisions have been measured simultaneously using a calibrated magnetic spectrograph. Among these processes, the $I^\cdot$ meso…

nucl-ex2003

Measurement of Spin Correlation Parameters A $_{N N}$ , A $_{S S}$ , and A_ $S L$ at 2.1 GeV in Proton-Proton Elastic Scattering

F. Bauer, J. Bisplinghoff, K. BÃ¼Ãer +29

At the Cooler Synchrotron COSY/JÃ¼lich spin correlation parameters in elastic proton-proton (pp) scattering have been measured with a 2.11 GeV polarized proton beam and a polarized…

nucl-ex1998

P-wave dominance in the pd -> 3He pi+ pi- reaction near threshold measured with the MOMO experiment at COSY

F. Bellemann, A. Berg, J. Bisplinghoff +24

The cross section of the pd -> 3He pi+ pi - reaction has been measured at the MOMO facility in a kinematically complete experiment at a c. m. excess energy of Q = 70 MeV. The energ…

nucl-ex2015

Strangeness Photoproduction at the BGO-OD Experiment

T. C. Jude, S. Alef, D. Bayadilov +61

BGO-OD is a newly commissioned experiment to investigate the internal structure of the nucleon, using an energy tagged bremsstrahlung photon beam at the ELSA electron facility. The…

nucl-ex1998

Test of Time Reversal Invariance in Polarized Proton-Deuteron Scattering

TRI collaboration, J. Bisplinghoff, J. Ernst +7

A novel test of time-reversal invariance in proton-deuteron scattering is planned as an internal target transmission experiment at the cooler synchrotron COSY. The P-even, T-odd ob…

Exclusive rho^0 muoproduction on transversely polarised protons and deuterons

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +217

The transverse target spin azimuthal asymmetry A_UT in hard exclusive production of rho^0 mesons was measured at COMPASS by scattering 160 GeV/c muons off transversely polarised pr…

hep-ex2011

Upper limits for a narrow resonance in the reaction p + p -> K^+ + (Lambda p)

A. Budzanowski, A. Chatterjee, H. Clement +26

The reaction pp -> K^+ + (Lambda p) has been measured at T_p = 1.953 GeV and Î= 0 deg with a high missing mass resolution in order to study the Lambda p final state interaction. N…

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…

D* and D Meson Production in Muon Nucleon Interactions at 160 GeV/c

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +217

The production of D* and D mesons in inelastic scattering of 160 GeV/c muons off a ^6LiD target has been investigated with the COMPASS spectrometer at CERN for 0.003 (GeV/c)^2 < Q^…

hep-ex2016

Observation of a new narrow axial-vector meson $a_{1} (1420)$

C. Adolph, R. Akhunzyanov, M. G. Alexeev +201

The COMPASS collaboration at CERN has measured diffractive dissociation of 190 GeV/ $c$ pions into the $I ¨ ^{-} I ¨ ^{-} I ¨ ^{+}$ final state using a stationary hydrogen target. A partial-wave…

nucl-ex2009

Cross sections of the $pp \to K^{+} I^£^{+} n$ reaction close to threshold

The HIRES Collaboration, A. Budzanowski, A. Chatterjee +27

The paper is obsolete

nucl-ex1999

Measurement of p + d -> 3He + eta in S(11) Resonance

M. Betigeri, J. Bojowald, A. Budzanowski +36

We have measured the reaction p + d -> 3He + eta at a proton beam energy of 980 MeV, which is 88.5 MeV above threshold using the new ``germanium wall'' detector system. A missing--…

hep-ex2016

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…

nucl-ex2009

Precision measurements of the pp\to Ï^+pn and pp\to Ï^+d reactions: importance of long-range and tensor force effects

A. Budzanowski, A. Chatterjee, P. Hawranek +28

Inclusive measurements of pion production in proton--proton collisions in the forward direction were undertaken at 400 and 600 MeV at COSY using the Big Karl spectrograph. The high…

nucl-ex2016

Study of the pd(dp) -> 3He pi pi reactions close to threshold

F. Bellemann, A. Berg, J. Bisplinghoff +19

New experimental data on the pd -> 3He pi+ pi- reaction obtained with the COSY-MOMO detector below the three-pion threshold are presented. The reaction was also studied in inverse…

nucl-ex2008

Cross Section and Tensor Analysing Power of the $d d \to I^\cdot I^\pm$ Reaction Near Threshold

The GEM Collaboration, A. Budzanowski, A. Chatterjee +29

The angular distributions of the unpolarised differential cross section and tensor analysing power $A_{xx}$ of the $d d \to I^\pm I^\cdot$ reaction have been measured at an excess energy…

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…

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…

nucl-ex2006

Study of the $p d \to^{3} He K^{+} K^{-}$ and $p d \to^{3} He I ¨ $ reactions close to threshold

F. Bellemann, A. Berg, J Bisplinghoff +19

Two--kaon production in proton--deuteron collisions has been studied at three energies close to threshold using a calibrated magnetic spectrograph to measure the final $^{3}$ He and a…

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…

physics.ins-det2020

The BGOOD experimental setup at ELSA

S. Alef, P. Bauer, D. Bayadilov +58

The BGOOD experiment at the ELSA facility in Bonn has been commissioned within the framework of an international collaboration. The experiment pursues a systematic investigation of…

hep-ex2017

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 spin effects in hadron-pair production from semi-inclusive deep inelastic scattering

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +212

First measurements of azimuthal asymmetries in hadron-pair production in deep-inelastic scattering of muons on transversely polarised ^6LiD (deuteron) and NH_3 (proton) targets are…

Leading order determination of the gluon polarisation from DIS events with high-p_T hadron pairs

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +212

We present a determination of the gluon polarisation Delta g/g in the nucleon, based on the longitudinal double-spin asymmetry of DIS events with a pair of large transverse-momentu…

nucl-ex2010

Study of the $p +^{6}$ Li $\to I^\cdot +^{7}$ Be reaction 11.3 MeV above threshold

A. Budzanowski, A. Chatterjee, P. Hawranek +24

The cross section for the reaction $p +^{6} Li \to I^\cdot +^{7} Be$ was measured at an excess energy of 11.28 MeV above threshold by detecting the recoiling $^{7}$ Be nuclei. A dedica…

Leading and Next-to-Leading Order Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +217

The gluon polarisation in the nucleon was measured using open charm production by scattering 160 GeV/c polarised muons off longitudinally polarised protons or deuterons. The data w…

Experimental investigation of transverse spin asymmetries in muon-p SIDIS processes: Collins asymmetries

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +215

The COMPASS Collaboration at CERN has measured the transverse spin azimuthal asymmetry of charged hadrons produced in semi-inclusive deep inelastic scattering using a 160 GeV posit…

hep-ex2005

Measurement of the Vector and Tensor Polarisation of Proton and Deuteron Beams

The GEM Collaboration, M. Lesiak, M. Abdel-Bary +32

Measurement of the d + d -> 4He + eta reaction using vector and tensor polarised beam has been performed at COSY using Big Karl magnetic spectrograph. The beam polarisation necessa…

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…

Hadron Transverse Momentum Distributions in Muon Deep Inelastic Scattering at 160 GeV/ $c$

C. Adolph, M. G. Alekseev, V. Yu. Alexakhin +207

Multiplicities of charged hadrons produced in deep inelastic muon scattering off a $^{6}$ LiD target have been measured as a function of the DIS variables $x_{B j}$ , $Q^{2}$ , $W^{2}$ and t…

hep-ex2009

Collins and Sivers asymmetries for pions and kaons in muon-deuteron DIS

The COMPASS Collaboration, M. Alekseev, V. Yu. Alexakhin +238

The measurements of the Collins and Sivers asymmetries of identified hadrons produced in deep-inelastic scattering of 160 GeV/c muons on a transversely polarised 6LiD target at COM…

Measurement of radiative widths of $a_{2} (1320)$ and $I ¨ _{2} (1670)$

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

The COMPASS Collaboration at CERN has investigated the reaction $I ¨ ^{-} I^^{3} \to I ¨ ^{-} I ¨ ^{-} I ¨ ^{+}$ embedded in the Primakoff reaction of $190 GeV$ pions scattering in the C…

First Measurement of Chiral Dynamics in Ï^- Î³-> Ï^- Ï^- Ï^+

M. G. Alekseev, V. Yu. Alexakhin, Yu. Alexandrov +202

The COMPASS collaboration at CERN has investigated the Ï^- Î³-> Ï^- Ï^- Ï^+ reaction at center-of-momentum energy below five pion masses, sqrt(s) < 5 m(Ï), embedded in the Pri…

hep-ex2010

Cross section of the $pp \to K^{+} I^£^{+} n$ reaction close to threshold

A. Budzanowski, A. Chatterjee, H. Clement +26

We have measured inclusive data on $K^{+}$ -meson production in $pp$ collisions at COSY JÃ¼lich close to the hyperon production threshold and determined the hyperon-nucleon invariant…