Related papers: Probing transversity by measuring $\Lambda$ polari…

First extraction of transversity from data on lepton-hadron scattering and hadronic collisions

We present the first extraction of the transversity distribution based on the global analysis of pion-pair production in deep-inelastic scattering and in proton-proton collisions with one transversely polarized proton. The extraction relies…

High Energy Physics - Phenomenology · Physics 2018-10-02 Marco Radici

Beyond Collins and Sivers: further measurements of the target transverse spin-dependent azimuthal asymmetries in semi-inclusive DIS from COMPASS

In semi-inclusive DIS of polarized leptons on a transversely polarized target eight azimuthal modulations appear in the cross-section. Within QCD parton model four azimuthal asymmetries can be interpreted at leading order, two of them being…

High Energy Physics - Experiment · Physics 2007-05-23 Aram Kotzinian

First measurement of the Sivers asymmetry for gluons from SIDIS data

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 asymmetry of hadrons produced in semi-inclusive deep…

High Energy Physics - Experiment · Physics 2017-09-13 C. Adolph , M. Aghasyan , R. Akhunzyanov , M. G. Alexeev , G. D. Alexeev , A. Amoroso , V. Andrieux , N. V. Anfimov , V. Anosov , A. Antoshkin , K. Augsten , W. Augustyniak , A. Austregesilo , C. D. R. Azevedo , B. Badelek , F. Balestra , M. Ball , J. Barth , R. Beck , Y. Bedfer , J. Bernhard , K. Bicker , E. R. Bielert , R. Birsa , M. Bodlak , P. Bordalo , F. Bradamante , C. Braun , A. Bressan , M. Buechele , W. -C. Chang , C. Chatterjee , M. Chiosso , I. Choi , S. -U. Chung , A. Cicuttin , M. L. Crespo , Q. Curiel , S. Dalla Torre , S. S. Dasgupta , S. Dasgupta , O. Yu. Denisov , L. Dhara , S. V. Donskov , N. Doshita , Ch. Dreisbach , V. Duic , W. Duennweber , M. Dziewiecki , A. Efremov , P. D. Eversheim , W. Eyrich , M. Faessler , A. Ferrero , M. Finger , M. Finger , H. Fischer , C. Franco , N. du Fresne von Hohenesche , J. M. Friedrich , V. Frolov , E. Fuchey , F. Gautheron , O. P. Gavrichtchouk , S. Gerassimov , J. Giarra , F. Giordano , I. Gnesi , M. Gorzellik , S. Grabmueller , A. Grasso , M. Grosse Perdekamp , B. Grube , T. Grussenmeyer , A. Guskov , F. Haas , D. Hahne , G. Hamar , D. von Harrach , F. H. Heinsius , R. Heitz , F. Herrmann , N. Horikawa , N. d'Hose , C. -Y. Hsieh , S. Huber , S. Ishimoto , A. Ivanov , Yu. Ivanshin , T. Iwata , V. Jary , R. Joosten , P. Joerg , E. Kabuss , A. Kerbizi , B. Ketzer , G. V. Khaustov , Yu. A. Khokhlov , Yu. Kisselev , F. Klein , K. Klimaszewski , J. H. Koivuniemi , V. N. Kolosov , K. Kondo , K. Koenigsmann , I. Konorov , V. F. Konstantinov , A. M. Kotzinian , O. M. Kouznetsov , M. Kraemer , P. Kremser , F. Krinner , Z. V. Kroumchtein , Y. Kulinich , F. Kunne , K. Kurek , R. P. Kurjata , A. A. Lednev , A. Lehmann , M. Levillain , S. Levorato , Y. -S. Lian , J. Lichtenstadt , R. Longo , A. Maggiora , A. Magnon , N. Makins , N. Makke , G. K. Mallot , B. Marianski , A. Martin , J. Marzec , J. Matousek , H. Matsuda , T. Matsuda , G. V. Meshcheryakov , M. Meyer , W. Meyer , Yu. V. Mikhailov , M. Mikhasenko , E. Mitrofanov , N. Mitrofanov , Y. Miyachi , A. Nagaytsev , F. Nerling , D. Neyret , J. Novy , W. -D. Nowak , G. Nukazuka , A. S. Nunes , A. G. Olshevsky , I. Orlov , M. Ostrick , D. Panzieri , B. Parsamyan , S. Paul , J. -C. Peng , F. Pereira , M. Pesek , D. V. Peshekhonov , N. Pierre , S. Platchkov , J. Pochodzalla , V. A. Polyakov , J. Pretz , M. Quaresma , C. Quintans , S. Ramos , C. Regali , G. Reicherz , C. Riedl , N. S. Rogacheva , M. Roskot , D. I. Ryabchikov , A. Rybnikov , A. Rychter , R. Salac , V. D. Samoylenko , A. Sandacz , C. Santos , S. Sarkar , I. A. Savin , T. Sawada , G. Sbrizzai , P. Schiavon , K. Schmidt , H. Schmieden , K. Schoenning , E. Seder , A. Selyunin , L. Silva , L. Sinha , S. Sirtl , M. Slunecka , J. Smolik , A. Srnka , D. Steffen , M. Stolarski , O. Subrt , M. Sulc , H. Suzuki , A. Szabelski , T. Szameitat , P. Sznajder , S. Takekawa , M. Tasevsky , S. Tessaro , F. Tessarotto , F. Thibaud , A. Thiel , F. Tosello , V. Tskhay , S. Uhl , J. Veloso , M. Virius , J. Vondra , S. Wallner , T. Weisrock , M. Wilfert , J. ter Wolbeek , K. Zaremba , P. Zavada , M. Zavertyaev , E. Zemlyanichkina , N. Zhuravlev , M. Ziembicki , A. Zink

Transversely polarized Drell-Yan measurements at COMPASS

The exploration of the transverse spin structure of the nucleon by measuring spin (in)dependent azimuthal asymmetries in semi-inclusive DIS (SIDIS) and in Drell-Yan processes is one of the main objectives of the COMPASS experiment at CERN…

High Energy Physics - Experiment · Physics 2019-08-08 Bakur Parsamyan

Accessing gluon polarization with high-$P_T$ hadrons in SIDIS

A recent global QCD analysis of jet production and other polarized scattering data has found the presence of negative solutions for the gluon helicity distribution in the proton, $\Delta g$, along with the traditional $\Delta g > 0$…

High Energy Physics - Phenomenology · Physics 2026-05-04 R. M. Whitehill , Yiyu Zhou , N. Sato , W. Melnitchouk

Single hadron transverse spin asymmetries from COMPASS

Transverse spin physics is an important part of the scientific programme of the COMPASS experiment at CERN. The analysis of the data taken with the target polarized orthogonally to the 160 GeV/c muon beam momentum has allowed to measure for…

High Energy Physics - Experiment · Physics 2008-11-26 F. Bradamante

Transversity and Spin Structure Functions

Measurements of single-spin asymmetries for semi-inclusive electro-production of pions and kaons in deep-inelastic scattering with transverse target polarization open a new window on the transverse quark and gluon structure of the nucleon.…

High Energy Physics - Experiment · Physics 2007-05-23 H. E. Jackson

Azimuthal asymmetries in the unpolarized SIDIS cross section at COMPASS

The study of the spin structure of the nucleon and of the effects rising from the quarks transverse momentum are part of the scientific program of COMPASS, a fixed target experiment at the CERN SPS. The azimuthal asymmetries which appear in…

High Energy Physics - Experiment · Physics 2019-08-14 Giulio Sbrizzai

Predictions for double spin asymmetry A_{LT} in Semi Inclusive DIS

In the leading order of QCD parton model of Semi Inclusive Deep Inelastic Scattering (SIDIS) the double spin asymmetry $A_{LT}$ arises due to the longitudinal polarization of quarks in the transversely polarized nucleon. The corresponding…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Kotzinian , B. Parsamyan , A. Prokudin

Measurements of Unpolarized Azimuthal Asymmetries at COMPASS

Azimuthal Asymmetries in unpolarized SIDIS can be used to probe the transverse momentum of quarks inside the nucleon. Furthermore, they give access to the so-far unmeasured Boer-Mulders function. We report on the first measurement of…

High Energy Physics - Experiment · Physics 2019-08-13 W. Käfer

Single spin asymmetry $A_{UL}^{\sin(2\phi_h-2\phi_R)}$ in dihadron semi-inclusive DIS

The single longitudinal spin asymmetry $A_{UL}^{\sin(2\phi_h-2\phi_R)}$ of dihadron production in semi-inclusive deep inelastic scattering (SIDIS) is examined through helicity-dependent dihadron fragmentation function (DiFF) $G_1^\perp$.…

High Energy Physics - Phenomenology · Physics 2020-08-05 Xuan Luo , Hao Sun

Transverse Lambda polarization in semi-inclusive DIS

Following a previous description of Lambda and Lambda-bar polarization in unpolarized p-p interactions, within a perturbative QCD factorization scheme with new polarizing fragmentation functions, here we investigate the transverse…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Anselmino , D. Boer , U. D'Alesio , F. Murgia

Single spin asymmetry $A _ { U L } ^ { \sin ( 3 \phi _ { h } - \phi_{ R } ) }$ in dihadron production in SIDIS

In the field of particle physics, the phenomenon of dihadron production in semi-inclusive deep inelastic scattering (SIDIS) process has always been a significant focus. This paper focuses on the single longitudinal spin asymmetry $A_{UL…

High Energy Physics - Phenomenology · Physics 2025-09-05 Lei Tan , Gang Li , Mao Song , Xuan Luo

First glances at the transversity parton distribution through dihadron fragmentation functions

We present first observations of the transversity parton distribution based on an analysis of pion-pair production in deep inelastic scattering off transversely polarized targets. The extraction of transversity relies on the knowledge of…

High Energy Physics - Phenomenology · Physics 2011-10-27 Alessandro Bacchetta , A. Courtoy , Marco Radici

ECCE unpolarized TMD measurements

We performed feasibility studies for various measurements that are related to unpolarized TMD distribution and fragmentation functions. The processes studied include semi-inclusive Deep inelastic scattering (SIDIS) where single hadrons…

High Energy Physics - Experiment · Physics 2023-08-09 R. Seidl , A. Vladimirov , J. K. Adkins , Y. Akiba , A. Albataineh , M. Amaryan , I. C. Arsene , C. Ayerbe Gayoso , J. Bae , X. Bai , M. D. Baker , M. Bashkanov , R. Bellwied , F. Benmokhtar , V. Berdnikov , J. C. Bernauer , F. Bock , W. Boeglin , M. Borysova , E. Brash , P. Brindza , W. J. Briscoe , M. Brooks , S. Bueltmann , M. H. S. Bukhari , A. Bylinkin , R. Capobianco , W. -C. Chang , Y. Cheon , K. Chen , K. -F. Chen , K. -Y. Cheng , M. Chiu , T. Chujo , Z. Citron , E. Cline , E. Cohen , T. Cormier , Y. Corrales Morales , C. Cotton , J. Crafts , C. Crawford , S. Creekmore , C. Cuevas , J. Cunningham , G. David , C. T. Dean , M. Demarteau , S. Diehl , N. Doshita , R. Dupré , J. M. Durham , R. Dzhygadlo , R. Ehlers , L. El Fassi , A. Emmert , R. Ent , C. Fanelli , R. Fatemi , S. Fegan , M. Finger , M. Finger , J. Frantz , M. Friedman , I. Friscic , D. Gangadharan , S. Gardner , K. Gates , F. Geurts , R. Gilman , D. Glazier , E. Glimos , Y. Goto , N. Grau , S. V. Greene , A. Q. Guo , L. Guo , S. K. Ha , J. Haggerty , T. Hayward , X. He , O. Hen , D. W. Higinbotham , M. Hoballah , T. Horn , A. Hoghmrtsyan , P. -h. J. Hsu , J. Huang , G. Huber , A. Hutson , K. Y. Hwang , C. E. Hyde , M. Inaba , T. Iwata , H. S. Jo , K. Joo , N. Kalantarians , G. Kalicy , K. Kawade , S. J. D. Kay , A. Kim , B. Kim , C. Kim , M. Kim , Y. Kim , Y. Kim , E. Kistenev , V. Klimenko , S. H. Ko , I. Korover , W. Korsch , G. Krintiras , S. Kuhn , C. -M. Kuo , T. Kutz , J. Lajoie , D. Lawrence , S. Lebedev , H. Lee , J. S. H. Lee , S. W. Lee , Y. -J. Lee , W. Li , W. Li , X. Li , X. Li , Y. T. Liang , S. Lim , C. -H. Lin , D. X. Lin , K. Liu , M. X. Liu , K. Livingston , N. Liyanage , W. J. Llope , C. Loizides , E. Long , R. -S. Lu , Z. Lu , W. Lynch , D. Marchand , M. Marcisovsky , C. Markert , P. Markowitz , H. Marukyan , P. McGaughey , M. Mihovilovic , R. G. Milner , A. Milov , Y. Miyachi , A. Mkrtchyan , P. Monaghan , R. Montgomery , D. Morrison , A. Movsisyan , H. Mkrtchyan , A. Mkrtchyan , C. Munoz Camacho , M. Murray , K. Nagai , J. Nagle , I. Nakagawa , C. Nattrass , D. Nguyen , S. Niccolai , R. Nouicer , G. Nukazuka , M. Nycz , V. A. Okorokov , S. Orešić , J. D. Osborn , C. O'Shaughnessy , S. Paganis , Z Papandreou , S. F. Pate , M. Patel , C. Paus , G. Penman , M. G. Perdekamp , D. V. Perepelitsa , H. Periera da Costa , K. Peters , W. Phelps , E. Piasetzky , C. Pinkenburg , I. Prochazka , T. Protzman , M. L. Purschke , J. Putschke , J. R. Pybus , R. Rajput-Ghoshal , J. Rasson , B. Raue , K. Read , K. Røed , R. Reed , J. Reinhold , E. L. Renner , J. Richards , C. Riedl , T. Rinn , J. Roche , G. M. Roland , G. Ron , M. Rosati , C. Royon , J. Ryu , S. Salur , N. Santiesteban , R. Santos , M. Sarsour , J. Schambach , A. Schmidt , N. Schmidt , C. Schwarz , J. Schwiening , A. Sickles , P. Simmerling , S. Sirca , D. Sharma , Z. Shi , T. -A. Shibata , C. -W. Shih , S. Shimizu , U. Shrestha , K. Slifer , K. Smith , D. Sokhan , R. Soltz , W. Sondheim , J. Song , J. Song , I. I. Strakovsky , P. Steinberg , P. Stepanov , J. Stevens , J. Strube , P. Sun , X. Sun , K. Suresh , V. Tadevosyan , W. -C. Tang , S. Tapia Araya , S. Tarafdar , L. Teodorescu , D. Thomas , A. Timmins , L. Tomasek , N. Trotta , R. Trotta , T. S. Tveter , E. Umaka , A. Usman , H. W. van Hecke , C. Van Hulse , J. Velkovska , E. Voutier , P. K. Wang , Q. Wang , Y. Wang , Y. Wang , D. P. Watts , N. Wickramaarachchi , L. Weinstein , M. Williams , C. -P. Wong , L. Wood , M. H. Wood , C. Woody , B. Wyslouch , Z. Xiao , Y. Yamazaki , Y. Yang , Z. Ye , H. D. Yoo , M. Yurov , N. Zachariou , W. A. Zajc , J. Zhang , Y. Zhang , Y. X. Zhao , X. Zheng , P. Zhuang

Update on transversity and Collins functions from SIDIS and e+ e- data

We present an update of a previous global analysis of the experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS), from the HERMES and COMPASS Collaborations, and in e+ e- -> h1 h2 X processes, from…

High Energy Physics - Phenomenology · Physics 2011-03-22 M. Anselmino , M. Boglione , U. D'Alesio , A. Kotzinian , F. Murgia , A. Prokudin , S. Melis

Probing transverse quark polarization via azimuthal asymmetries in leptoproduction

We consider the leading order result for polarized leptoproduction, putting emphasis on transverse momentum dependent effects appearing in azimuthal asymmetries. Measurements of weighted cross sections enable extraction of the distribution…

High Energy Physics - Phenomenology · Physics 2009-10-30 A. M. Kotzinian , P. J. Mulders

Transverse Polarization of Lambda and Lambda-bar Hyperons in Quasireal Photoproduction

The HERMES experiment has measured the transverse polarization of Lambda and Lambda-bar hyperons produced inclusively in quasireal photoproduction at a positron beam energy of 27.6 GeV. The transverse polarization of the Lambda hyperon is…

High Energy Physics - Experiment · Physics 2012-08-03 The HERMES Collaboration , A. Airapetian

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

Hadron leptoproduction in Semi-Inclusive measurements of Deep-Inelastic Scattering (SIDIS) on unpolarised nucleons allows one to get information on the intrinsic transverse momentum of quarks in a nucleon and on the Boer-Mulders function…

High Energy Physics - Experiment · Physics 2020-06-24 J. Agarwala , M. G. Alexeev , G. D. Alexeev , A. Amoroso , V. Andrieux , N. V. Anfimov , V. Anosov , A. Antoshkin , K. Augsten , W. Augustyniak , C. D. R. Azevedo , B. Badelek , F. Balestra , M. Ball , J. Barth , R. Beck , Y. Bedfer , J. Berenguer Antequera , J. Bernhard , M. Bodlak , P. Bordalo , F. Bradamante , A. Bressan , M. Buechele , V. E. Burtsev , W. -C. Chang , C. Chatterjee , M. Chiosso , A. G. Chumakov , S. -U. Chung , A. Cicuttin , P. M. M. Correia , M. L. Crespo , D. D'Ago , S. Dalla Torre , S. S. Dasgupta , S. Dasgupta , I. Denisenko , O. Yu. Denisov , L. Dhara , S. V. Donskov , N. Doshita , Ch. Dreisbach , W. Duennweber , R. R. Dusaev , A. Efremov , P. D. Eversheim , M. Faessler , A. Ferrero , M. Finger , M. Finger , H. Fischer , C. Franco , J. M. Friedrich , V. Frolov , F. Gautheron , O. P. Gavrichtchouk , S. Gerassimov , J. Giarra , I. Gnesi , M. Gorzellik , A. Grasso , A. Gridin , M. Grosse Perdekamp , B. Grube , A. Guskov , D. von Harrach , R. Heitz , F. Herrmann , N. Horikawa , N. d'Hose , C. -Y. Hsieh , S. Huber , S. Ishimoto , A. Ivanov , T. Iwata , M. Jandek , T. Jary , R. Joosten , P. Joerg , E. Kabuss , F. Kaspar , A. Kerbizi , B. Ketzer , G. V. Khaustov , Yu. A. Khokhlov , Yu. Kisselev , F. Klein , J. H. Koivuniemi , V. N. Kolosov , K. Kondo , I. Konorov , V. F. Konstantinov , A. M. Kotzinian , O. M. Kouznetsov , A. Koval , Z. Kral , F. Krinner , Y. Kulinich , F. Kunne , K. Kurek , R. P. Kurjata , A. Kveton , K. Lavickova , S. Levorato , Y. -S. Lian , J. Lichtenstadt , P. -J. Lin , R. Longo , V. E. Lyubovitskij , A. Maggiora , A. Magnon , N. Makins , N. Makke , G. K. Mallot , A. Maltsev , S. A. Mamon , B. Marianski , A. Martin , J. Marzec , J. Matousek , T. Matsuda , G. Mattson , G. V. Meshcheryakov , M. Meyer , W. Meyer , Yu. V. Mikhailov , M. Mikhasenko , E. Mitrofanov , N. Mitrofanov , Y. Miyachi , A. Moretti , A. Nagaytsev , C. Naim , D. Neyret , J. Novy , W. -D. Nowak , G. Nukazuka , A. S. Nunes , A. G. Olshevskiy , M. Ostrick , D. Panzieri , B. Parsamyan , S. Paul , H. Pekeler , J. -C. Peng , F. Pereira , M. Pesek , D. V. Peshekhonov , M. Peskova , N. Pierre , S. Platchkov , J. Pochodzalla , V. A. Polyakov , J. Pretz , M. Quaresma , C. Quintans , S. Ramos , G. Reicherz , C. Riedl , D. I. Ryabchikov , T. Rudnicki , A. Rybnikov , A. Rychter , V. D. Samoylenko , A. Sandacz , S. Sarkar , I. A. Savin , G. Sbrizzai , H. Schmieden , A. Selyunin , L. Sinha , M. Slunecka , J. Smolik , A. Srnka , D. Steffen , M. Stolarski , O. Subrt , M. Sulc , H. Suzuki , A. Szabelski , P. Sznajder , S. Tessaro , F. Tessarotto , A. Thiel , J. Tomsa , F. Tosello , A. Townsend , V. Tskhay , S. Uhl , B. I. Vasilishin , A. Vauth , B. M. Veit , J. Veloso , B. Ventura , A. Vidon , M. Virius , M. Wagner , S. Wallner , M. Wilfert , K. Zaremba , P. Zavada , M. Zavertyaev , M. Zemko , E. Zemlyanichkina , Y. Zhao , M. Ziembicki

First Measurement of the Transverse Spin Asymmetries of the Deuteron in Semi-Inclusive Deep Inelastic Scattering

First measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarized 6-LiD target are presented. The data were taken in 2002 with the COMPASS spectrometer…

High Energy Physics - Experiment · Physics 2012-08-27 The COMPASS Collaboration