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Publications (71)

hep-ph1996

A model for $F_{L}$ and $R = F_{L} / F_{T}$ at low $x$ and low $Q^{2}$

B. Badelek, J. Kwiecinski, A. Stasto

A model for the longitudinal structure function $F_{L}$ at low $x$ and low $Q^{2}$ is presented, which includes the kinematical constraint $F_{L} \sim Q^{4}$ as $Q^{2} \to 0$ . It is…

hep-ex2018

K $^{-}$ over K $^{+}$ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

R. Akhunzyanov, M. G. Alexeev, G. D. Alexeev +207

The K $^{-}$ over K $^{+}$ multiplicity ratio is measured in deep-inelastic scattering, for the first time for kaons carrying a large fraction $z$ of the virtual-photon energy. The d…

hep-ph2000

Parametrisation of F_2^gamma at low Q^2 and of sigma(gamma,gamma) and sigma(gamma^*,gamma) at high energies

B. Badelek, M. Krawczyk, J. Kwiecinski +1

A parametrisation of the real photon structure function F_2^gamma in the low Q^2, low x region is formulated. It includes both the VMD and the QCD components, the latter suitably e…

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…

hep-ex2012

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…

hep-ex2021

Probing transversity by measuring $I^$ polarisation in SIDIS

M. G. Alexeev, G. D. Alexeev, A. Amoroso +196

Based on the observation of sizeable target-transverse-spin asymmetries in single-hadron and hadron-pair production in Semi-Inclusive measurements of Deep Inelastic Scattering (SID…

hep-ex2017

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…

hep-ph1999

F_2^gamma at low Q^2 and sigma_{Î³Î³} at high energies

B. Badelek, J. Kwiecinski, A. Stasto

The parametrisation of the photon structure function in the low Q^2 region is formulated. It includes the VMD contribution and the QCD improved parton model component suitably extr…

hep-ex2012

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-ex2014

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-ex2017

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-ex2013

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-ex2014

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…

hep-ex2015

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…

hep-ex2023

High-statistics measurement of Collins and Sivers asymmetries for transversely polarised deuterons

G. D. Alexeev, M. G. Alexeev, C. Alice +183

New results are presented on a high-statistics measurement of Collins and Sivers asymmetries of charged hadrons produced in deep inelastic scattering of muons on a transversely pol…

hep-ex2019

Measurement of the cross section for hard exclusive $I ¨ ^{0}$ leptoproduction

M. G. Alexeev, G. D. Alexeev, A. Amoroso +199

We report on a measurement of hard exclusive $I ¨ ^{0}$ muoproduction on the proton by COMPASS using 160 GeV/ $c$ polarised $I^¼^{+}$ and $I^¼^{-}$ beams of the CERN SPS impinging on a liquid…

hep-ex2026

First Observation of an Exotic Reggeon

G. D. Alexeev, M. G. Alexeev, C. Alice +180

We present new \compass high-statistics measurements of the peripheral production of $I^\cdot I ¨ ^{-}$ and $I^\cdot^{'} I ¨ ^{-}$ pairs in the reactions $I ¨ ^{-} p \to I^\cdot^{(')} I ¨ ^{-} p$ . For the…

hep-ph2001

TESLA Technical Design Report Part III: Physics at an e+e- Linear Collider

R. -D. Heuer, D. J. Miller, F. Richard +236

The TESLA Technical Design Report Part III: Physics at an e+e- Linear Collider

hep-ex2013

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…

hep-ex2022

Double $J / I ¨ $ production in pion-nucleon scattering at COMPASS

G. D. Alexeev, M. G. Alexeev, A. Amoroso +191

We present the study of the production of double $J / I ¨ $ mesons using COMPASS data collected with a 190 GeV/ $c$ $I ¨ ^{-}$ beam scattering off NH $_{3}$ , Al and W targets. Kinematic dist…

hep-ex2018

Measurement of $P_{T}$ -weighted Sivers asymmetries in leptoproduction of hadrons

M. G. Alexeev, G. D. Alexeev, A. Amoroso +209

The transverse spin asymmetries measured in semi-inclusive leptoproduction of hadrons, when weighted with the hadron transverse momentum $P_{T}$ , allow for the extraction of importan…

hep-ex2014

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…

hep-ex2024

Measurement of the hard exclusive $I ¨ ^{0}$ muoproduction cross section at COMPASS

G. D. Alexeev, M. G. Alexeev, C. Alice +169

A new and detailed measurement of the cross section for hard exclusive neutral-pion muoproduction on the proton was performed in a wide kinematic region, with the photon virtuality…

hep-ex2023

Spin Density Matrix Elements in Exclusive $I ¨ ^{0}$ Meson Muoproduction

G. D. Alexeev, M. G. Alexeev, C. Alice +186

We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $I ¨ ^{0}$ meson muoproduction at COMPASS using 160~GeV/ $c$ polarised $I^¼^{+}$ and $I^¼^{-}$ beams…

hep-ex2022

The exotic meson $I ¨ _{1} (1600)$ with $J^{P C} = 1^{-+}$ and its decay into $I ¨ (770) I ¨ $

M. G. Alexeev, G. D. Alexeev, A. Amoroso +192

We study the spin-exotic $J^{P C} = 1^{-+}$ amplitude in single-diffractive dissociation of 190 GeV $/ c$ pions into $I ¨ ^{-} I ¨ ^{-} I ¨ ^{+}$ using a hydrogen target and confirm the $Ï_1(1600)…

hep-ph1996

Working Group Report on the Structure of the Proton

B. Badelek, J. Bartels, N. Brook +5

We summarize the developments on the structure of the proton that were studied at the Workshop on "HERA Physics" that was held in Durham in September 1995. We survey the latest str…

hep-ex2017

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…

hep-ex2014

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-ex2019

Letter of Intent: A New QCD facility at the M2 beam line of the CERN SPS (COMPASS++/AMBER)

B. Adams, C. A. Aidala, R. Akhunzyanov +263

A New QCD facility at the M2 beam line of the CERN SPS COMPASS++/AMBER

hep-ex2015

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-ex2004

Linear to Circular Polarisation Conversion using Birefringent Properties of Aligned Crystals for Multi-GeV Photons

NA59 Collaboration, A. Apyan, R. O. Avakian +27

We present the first experimental results on the use of a thick aligned Si crystal acting as a quarter wave plate to induce a degree of circular polarisation in a high energy linea…

hep-ex2025

Spectroscopy of Strange Mesons and First Observation of a Strange Crypto-Exotic State with $J^{P} = 0^{-}$

G. D. Alexeev, M. G. Alexeev, C. Alice +160

We measured the strange-meson spectrum in the scattering reaction $K^{-} + p \to K^{-} I ¨ ^{-} I ¨ ^{-} + p$ with the COMPASS spectrometer at CERN. Using the world's largest sample…

hep-ex2016

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…

hep-ex2016

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…

hep-ph2021

Triangle Singularity as the Origin of the $a_{1} (1420)$

G. D. Alexeev, M. G. Alexeev, A. Amoroso +194

The COMPASS experiment recently discovered a new isovector resonance-like signal with axial-vector quantum numbers, the $a_{1} (1420)$ , decaying to $f_{0} (980) I ¨ $ . With a mass too close…

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…

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…

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…

hep-ex1995

The Structure Function Ratios F2(Li)/F2(D) and F2(C)/F2(D) at small x

THE NEW MUON COLLABORATION, M. Arneodo, A. Arvidson +71

We present the structure function ratios F2(Li)/F2(D) and F2(C)/F2(D) measured in deep inelastic muon-nucleus scattering at a nominal incident muon energy of 200 GeV. The kinematic…

hep-ex2001

TESLA Technical Design Report, Part VI, Chapter 1: The Photon Collider at TESLA

B. Badelek, C. Blochinger, J. Blumlein +96

TESLA Technical Design Report, Part VI, Chapter 1: The Photon Collider at TESLA

hep-ex2014

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…

hep-ex2005

Results on the Coherent Interaction of High Energy Electrons and Photons in Oriented Single Crystals

NA59 Collaboration, A. Apyan, R. O. Avakian +27

The CERN-NA-59 experiment examined a wide range of electromagnetic processes for multi-GeV electrons and photons interacting with oriented single crystals. The various types of cry…

hep-ph1994

Shadowing in the Deuteron and the New $F_{2}^{n} / F_{2}^{p}$ Measurements

B. Badelek, J. Kwiecinski

The quantity $2 F_{2}^{d} (x, Q^{2}) / F_{2}^{p} (x, Q^{2}) - 1$ is calculated in the region of low $x$ and low- and moderate $Q^{2}$ relevant for recent NMC and E665 measurements as well as for the expe…

hep-ex2019

Contribution of exclusive diffractive processes to the measured azimuthal asymmetries in SIDIS

J. Agarwala, M. G. Alexeev, G. D. Alexeev +203

Hadron leptoproduction in Semi-Inclusive measurements of Deep-Inelastic Scattering (SIDIS) on unpolarised nucleons allows one to get information on the intrinsic transverse momentu…

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…

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…

hep-ex2017

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-ex2012

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…

hep-ex2025

Dihadron Transverse-Spin Asymmetries in Muon-Deuteron Deep-Inelastic Scattering

G. D. Alexeev, M. G. Alexeev, C. Alice +168

In 2022, the COMPASS collaboration performed semi-inclusive measurements of deep-inelastic muon-scattering on a transversely polarised deuteron (6LiD) target. From these data, tran…

hep-ex2012

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-ex2021

Spin Density Matrix Elements in Exclusive $I ¨ $ Meson Muoproduction $^{*}$

M. G. Alexeev, G. D. Alexeev, A. Amoroso +197

We report on a measurement of Spin Density Matrix Elements (SDMEs) in hard exclusive $I ¨ $ meson muoproduction on the proton at COMPASS using 160 GeV/ $c$ polarised $I^¼^{+}$ and $ Î…

hep-ex2023

Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of $I ¨ ^{0}$ mesons

G. D. Alexeev, M. G. Alexeev, C. Alice +188

The production of vector mesons in deep inelastic scattering is an interesting yet scarsely explored channel to study the transverse spin structure of the nucleon and the related p…

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…

hep-ex2017

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…

hep-ex2014

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 $160$ …

hep-ex2012

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…

hep-ex2004

Measurement of Coherent Emission and Linear Polarization of Photons by Electrons in the Strong Fields of Aligned Crystals

NA59 Collaboration, A. Apyan, R. O. Avakian +27

We present new results regarding the features of high energy photon emission by an electron beam of 178 GeV penetrating a 1.5 cm thick single Si crystal aligned at the Strings-Of-S…

hep-ex2004

Coherent Pair Production by Photons in the 20-170 GeV Energy Range Incident on Crystals and Birefringence

NA59 Collaboration, A. Apyan, R. O. Avakian +27

The cross section for coherent pair production by linearly polarised photons in the 20-170 GeV energy range was measured for photon aligned incidence on ultra-high quality diamond…

hep-ex2023

Final COMPASS results on the transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan process

G. D. Alexeev, M. G. Alexeev, C. Alice +180

The COMPASS Collaboration performed measurements of the Drell-Yan process in 2015 and 2018 using a 190 GeV/c $I ¨ ^{-}$ beam impinging on a transversely polarised ammonia target. Com…

hep-ph1999

Spin dependent structure function g_1 at low x and low Q^2

B. Badelek, J. Kiryluk, J. Kwiecinski

Theoretical description of the spin dependent structure function g_1(x,Q^2) in the region of low values of x and Q^2 is presented. It contains the Vector Meson Dominance contributi…

hep-ex2024

Multiplicities of positive and negative pions, kaons and unidentified hadrons from deep-inelastic scattering of muons off a liquid hydrogen target

G. D. Alexeev, M. G. Alexeev, C. Alice +166

The multiplicities of positive and negative pions, kaons and unidentified hadrons produced in deep-inelastic scattering are measured in bins of the Bjorken scaling variable $x$ , th…

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…

hep-ex2025

Coherent bremsstrahlung, coherent pair production, birefringence and polarimetry in the 20-170 GeV energy range using aligned crystals

NA59 Collaboration, A. Apyan, R. O. Avakian +27

The processes of coherent bremsstrahlung (CB) and coherent pair production (CPP) based on aligned crystal targets have been studied in the energy range 20-170 GeV. The experimental…

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…

hep-ex2012

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-ph2001

Spin structure function g_1 at low x: status and plans

B. Badelek

A brief review of measurements and expectations concerning the spin structure function g_1 of the nucleon at low values of the scaling variable x is given.

hep-ph2022

Longitudinal structure function $F_{L}$ at low $Q^{2}$ and low $x$ with model for higher twist: an update

B. Badelek, A. M. Stasto

A reanalysis of the model for the longitudinal structure function $F_{L} (x, Q^{2})$ at low $x$ and low $Q^{2}$ was undertaken, in view of the advent of the EIC. The model is based on the…

hep-ex2020

Antiproton over proton and K $^{-}$ over K $^{+}$ multiplicity ratios at high $z$ in DIS

M. G. Alexeev, G. D. Alexeev, A. Amoroso +195

The $p ˉ$ over p multiplicity ratio is measured in deep-inelastic scattering for the first time using (anti-) protons carrying a large fraction of the virtual-photon energ…

hep-ex2015

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…

hep-ex2014

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…

Publications (71)

A model for FL​ and R=FL​/FT​ at low x and low Q2

K− over K+ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

Parametrisation of F_2^gamma at low Q^2 and of sigma(gamma,gamma) and sigma(gamma^*,gamma) at high energies

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

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

Probing transversity by measuring I^ polarisation in SIDIS

Longitudinal double-spin asymmetry A1p​ and spin-dependent structure function g1p​ of the proton at small values of x and Q2

F_2^gamma at low Q^2 and sigma_{Î³Î³} at high energies

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

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

First measurement of the Sivers asymmetry for gluons from SIDIS data

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

Measurement of radiative widths of a2​(1320) and I¨2​(1670)

Interplay among transversity induced asymmetries in hadron leptoproduction

High-statistics measurement of Collins and Sivers asymmetries for transversely polarised deuterons

Measurement of the cross section for hard exclusive I¨0 leptoproduction

First Observation of an Exotic Reggeon

TESLA Technical Design Report Part III: Physics at an e+e- Linear Collider

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

Double J/I¨ production in pion-nucleon scattering at COMPASS

Measurement of PT​-weighted Sivers asymmetries in leptoproduction of hadrons

Search for exclusive photoproduction of Zc±​(3900) at COMPASS

Measurement of the hard exclusive I¨0 muoproduction cross section at COMPASS

Spin Density Matrix Elements in Exclusive I¨0 Meson Muoproduction

The exotic meson I¨1​(1600) with JPC=1−+ and its decay into I¨(770)I¨

Working Group Report on the Structure of the Proton

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

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

Letter of Intent: A New QCD facility at the M2 beam line of the CERN SPS (COMPASS++/AMBER)

The Spin Structure Function g1p​ of the Proton and a Test of the Bjorken Sum Rule

Linear to Circular Polarisation Conversion using Birefringent Properties of Aligned Crystals for Multi-GeV Photons

Spectroscopy of Strange Mesons and First Observation of a Strange Crypto-Exotic State with JP=0−

Final COMPASS results on the deuteron spin-dependent structure function g1d​ and the Bjorken sum rule

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

Triangle Singularity as the Origin of the a1​(1420)

New analysis of I^⋅I¨ tensor resonances measured at the COMPASS experiment

Observation of a new narrow axial-vector meson a1​(1420)

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

The Structure Function Ratios F2(Li)/F2(D) and F2(C)/F2(D) at small x

TESLA Technical Design Report, Part VI, Chapter 1: The Photon Collider at TESLA

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

Results on the Coherent Interaction of High Energy Electrons and Photons in Oriented Single Crystals

Shadowing in the Deuteron and the New F2n​/F2p​ Measurements

Contribution of exclusive diffractive processes to the measured azimuthal asymmetries in SIDIS

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

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

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

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

Dihadron Transverse-Spin Asymmetries in Muon-Deuteron Deep-Inelastic Scattering

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

Spin Density Matrix Elements in Exclusive I¨ Meson Muoproduction ∗

Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of I¨0 mesons

Exclusive I¨ meson muoproduction on transversely polarised protons

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

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

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

Measurement of Coherent Emission and Linear Polarization of Photons by Electrons in the Strong Fields of Aligned Crystals

Coherent Pair Production by Photons in the 20-170 GeV Energy Range Incident on Crystals and Birefringence

Final COMPASS results on the transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan process

Spin dependent structure function g_1 at low x and low Q^2

Multiplicities of positive and negative pions, kaons and unidentified hadrons from deep-inelastic scattering of muons off a liquid hydrogen target

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

Coherent bremsstrahlung, coherent pair production, birefringence and polarimetry in the 20-170 GeV energy range using aligned crystals

The COMPASS Setup for Physics with Hadron Beams

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

Spin structure function g_1 at low x: status and plans

Longitudinal structure function FL​ at low Q2 and low x with model for higher twist: an update

Antiproton over proton and K− over K+ multiplicity ratios at high z in DIS

Measurement of the charged-pion polarisability

Light isovector resonances in I¨−p→I¨−I¨−I¨+p at 190 GeV/c

Odd and Even Partial Waves of I^⋅I¨− and I^⋅′I¨− in I¨−p→I^⋅(′)I¨−p at 191GeV/c

A model for $F_{L}$ and $R = F_{L} / F_{T}$ at low $x$ and low $Q^{2}$

K $^{-}$ over K $^{+}$ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

Probing transversity by measuring $I^$ polarisation in SIDIS

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

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

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

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

Measurement of the cross section for hard exclusive $I ¨ ^{0}$ leptoproduction

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

Double $J / I ¨ $ production in pion-nucleon scattering at COMPASS

Measurement of $P_{T}$ -weighted Sivers asymmetries in leptoproduction of hadrons

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

Measurement of the hard exclusive $I ¨ ^{0}$ muoproduction cross section at COMPASS

Spin Density Matrix Elements in Exclusive $I ¨ ^{0}$ Meson Muoproduction

The exotic meson $I ¨ _{1} (1600)$ with $J^{P C} = 1^{-+}$ and its decay into $I ¨ (770) I ¨ $

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

Spectroscopy of Strange Mesons and First Observation of a Strange Crypto-Exotic State with $J^{P} = 0^{-}$

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

Triangle Singularity as the Origin of the $a_{1} (1420)$

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

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

Shadowing in the Deuteron and the New $F_{2}^{n} / F_{2}^{p}$ Measurements

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

Spin Density Matrix Elements in Exclusive $I ¨ $ Meson Muoproduction $^{*}$

Collins and Sivers transverse-spin asymmetries in inclusive muoproduction of $I ¨ ^{0}$ mesons

Exclusive $I ¨ $ meson muoproduction on transversely polarised protons

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

Longitudinal structure function $F_{L}$ at low $Q^{2}$ and low $x$ with model for higher twist: an update

Antiproton over proton and K $^{-}$ over K $^{+}$ multiplicity ratios at high $z$ in DIS

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

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