Improved measurement of the longitudinal spin transfer to Λ and Λ  hyperons in polarized proton-proton collisions at s =200 GeV

STAR Collaboration

doi:10.1103/PhysRevD.98.112009

Improved measurement of the longitudinal spin transfer to Λ and Λ hyperons in polarized proton-proton collisions at s =200 GeV

STAR Collaboration

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Abstract

The longitudinal spin transfer DLL to Λ and Λ hyperons produced in high-energy polarized proton-proton collisions is expected to be sensitive to the helicity distribution functions of strange quarks and antiquarks of the proton, and to longitudinally polarized fragmentation functions. We report an improved measurement of DLL from data obtained at a center-of-mass energy of s=200 GeV with the STAR detector at RHIC. The data have an approximately twelve times larger figure of merit than prior results and cover |η|<1.2 in pseudorapidity with transverse momenta pT up to 6 GeV/c. In the forward scattering hemisphere at largest pT, the longitudinal spin transfer is found to be DLL=-0.036±0.048(stat)±0.013(sys) for Λ hyperons and DLL=0.032±0.043(stat)±0.013(sys) for Λ antihyperons. The dependences on η and pT are presented and compared with model evaluations.

Original language	English
Article number	112009
Journal	Physical Review D
Volume	98
Issue number	11
DOIs	https://doi.org/10.1103/PhysRevD.98.112009
State	Published - Dec 1 2018
Externally published	Yes

Funding

We thank the RHIC Operations Group and RCF at BNL, the NERSC Center at LBNL, and the Open Science Grid consortium for providing resources and support. This work was supported in part by the Office of Nuclear Physics within the U.S. DOE Office of Science, the U.S. National Science Foundation, the Ministry of Education and Science of the Russian Federation, National Natural Science Foundation of China, Chinese Academy of Science, the Ministry of Science and Technology of China and the Chinese Ministry of Education, the National Research Foundation of Korea, Czech Science Foundation and Ministry of Education, Youth and Sports of the Czech Republic, Department of Atomic Energy and Department of Science and Technology of the Government of India, the National Science Centre of Poland, the Ministry of Science, Education and Sports of the Republic of Croatia, RosAtom of Russia and German Bundesministerium für Bildung, Wissenschaft, Forschung and Technologie (BMBF) and the Helmholtz Association.

Funders	Funder number
RosAtom of Russia and German Bundesministerium für Bildung, Wissenschaft, Forschung and Technologie
National Science Foundation
Office of Science
Nuclear Physics
Department of Science and Technology, Ministry of Science and Technology, India
National Natural Science Foundation of China
Ministerstvo Školství, Mládeže a Tělovýchovy
Grantová Agentura České Republiky
Ministry of Education of the People's Republic of China
Bundesministerium für Bildung und Forschung
Chinese Academy of Sciences
Ministry of Science and Technology of the People's Republic of China
Ministarstvo Obrazovanja, Znanosti i Sporta
Ministry of Education and Science of the Russian Federation
National Research Foundation of Korea
Narodowe Centrum Nauki
Helmholtz Association

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10.1103/PhysRevD.98.112009

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@article{cfaf06f7810c4a02a2bd6b878169583e,

title = "Improved measurement of the longitudinal spin transfer to Λ and Λ hyperons in polarized proton-proton collisions at s =200 GeV",

abstract = "The longitudinal spin transfer DLL to Λ and Λ hyperons produced in high-energy polarized proton-proton collisions is expected to be sensitive to the helicity distribution functions of strange quarks and antiquarks of the proton, and to longitudinally polarized fragmentation functions. We report an improved measurement of DLL from data obtained at a center-of-mass energy of s=200 GeV with the STAR detector at RHIC. The data have an approximately twelve times larger figure of merit than prior results and cover |η|<1.2 in pseudorapidity with transverse momenta pT up to 6 GeV/c. In the forward scattering hemisphere at largest pT, the longitudinal spin transfer is found to be DLL=-0.036±0.048(stat)±0.013(sys) for Λ hyperons and DLL=0.032±0.043(stat)±0.013(sys) for Λ antihyperons. The dependences on η and pT are presented and compared with model evaluations.",

author = "{STAR Collaboration} and J. Adam and L. Adamczyk and Adams, {J. R.} and Adkins, {J. K.} and G. Agakishiev and Aggarwal, {M. M.} and Z. Ahammed and I. Alekseev and Anderson, {D. M.} and R. Aoyama and A. Aparin and D. Arkhipkin and Aschenauer, {E. C.} and Ashraf, {M. U.} and F. Atetalla and A. Attri and Averichev, {G. S.} and X. Bai and V. Bairathi and K. Barish and Bassill, {A. J.} and A. Behera and R. Bellwied and A. Bhasin and Bhati, {A. K.} and J. Bielcik and J. Bielcikova and Bland, {L. C.} and Bordyuzhin, {I. G.} and Brandenburg, {J. D.} and Brandin, {A. V.} and D. Brown and J. Bryslawskyj and I. Bunzarov and J. Butterworth and H. Caines and {Calder{\'o}n De La Barca S{\'a}nchez}, M. and D. Cebra and R. Cendejas and I. Chakaberia and P. Chaloupka and Chan, {B. K.} and Chang, {F. H.} and Z. Chang and N. Chankova-Bunzarova and A. Chatterjee and S. Chattopadhyay and Chen, {J. H.} and X. Chen and J. Schambach",

note = "Publisher Copyright: {\textcopyright} 2018 authors. Published by the American Physical Society.",

year = "2018",

month = dec,

day = "1",

doi = "10.1103/PhysRevD.98.112009",

language = "English",

volume = "98",

journal = "Physical Review D",

issn = "2470-0010",

publisher = "American Physical Society",

number = "11",

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TY - JOUR

T1 - Improved measurement of the longitudinal spin transfer to Λ and Λ hyperons in polarized proton-proton collisions at s =200 GeV

AU - STAR Collaboration

AU - Adam, J.

AU - Adamczyk, L.

AU - Adams, J. R.

AU - Adkins, J. K.

AU - Agakishiev, G.

AU - Aggarwal, M. M.

AU - Ahammed, Z.

AU - Alekseev, I.

AU - Anderson, D. M.

AU - Aoyama, R.

AU - Aparin, A.

AU - Arkhipkin, D.

AU - Aschenauer, E. C.

AU - Ashraf, M. U.

AU - Atetalla, F.

AU - Attri, A.

AU - Averichev, G. S.

AU - Bai, X.

AU - Bairathi, V.

AU - Barish, K.

AU - Bassill, A. J.

AU - Behera, A.

AU - Bellwied, R.

AU - Bhasin, A.

AU - Bhati, A. K.

AU - Bielcik, J.

AU - Bielcikova, J.

AU - Bland, L. C.

AU - Bordyuzhin, I. G.

AU - Brandenburg, J. D.

AU - Brandin, A. V.

AU - Brown, D.

AU - Bryslawskyj, J.

AU - Bunzarov, I.

AU - Butterworth, J.

AU - Caines, H.

AU - Calderón De La Barca Sánchez, M.

AU - Cebra, D.

AU - Cendejas, R.

AU - Chakaberia, I.

AU - Chaloupka, P.

AU - Chan, B. K.

AU - Chang, F. H.

AU - Chang, Z.

AU - Chankova-Bunzarova, N.

AU - Chatterjee, A.

AU - Chattopadhyay, S.

AU - Chen, J. H.

AU - Chen, X.

AU - Schambach, J.

PY - 2018/12/1

Y1 - 2018/12/1

N2 - The longitudinal spin transfer DLL to Λ and Λ hyperons produced in high-energy polarized proton-proton collisions is expected to be sensitive to the helicity distribution functions of strange quarks and antiquarks of the proton, and to longitudinally polarized fragmentation functions. We report an improved measurement of DLL from data obtained at a center-of-mass energy of s=200 GeV with the STAR detector at RHIC. The data have an approximately twelve times larger figure of merit than prior results and cover |η|<1.2 in pseudorapidity with transverse momenta pT up to 6 GeV/c. In the forward scattering hemisphere at largest pT, the longitudinal spin transfer is found to be DLL=-0.036±0.048(stat)±0.013(sys) for Λ hyperons and DLL=0.032±0.043(stat)±0.013(sys) for Λ antihyperons. The dependences on η and pT are presented and compared with model evaluations.

AB - The longitudinal spin transfer DLL to Λ and Λ hyperons produced in high-energy polarized proton-proton collisions is expected to be sensitive to the helicity distribution functions of strange quarks and antiquarks of the proton, and to longitudinally polarized fragmentation functions. We report an improved measurement of DLL from data obtained at a center-of-mass energy of s=200 GeV with the STAR detector at RHIC. The data have an approximately twelve times larger figure of merit than prior results and cover |η|<1.2 in pseudorapidity with transverse momenta pT up to 6 GeV/c. In the forward scattering hemisphere at largest pT, the longitudinal spin transfer is found to be DLL=-0.036±0.048(stat)±0.013(sys) for Λ hyperons and DLL=0.032±0.043(stat)±0.013(sys) for Λ antihyperons. The dependences on η and pT are presented and compared with model evaluations.

UR - http://www.scopus.com/inward/record.url?scp=85059479764&partnerID=8YFLogxK

U2 - 10.1103/PhysRevD.98.112009

DO - 10.1103/PhysRevD.98.112009

M3 - Article

AN - SCOPUS:85059479764

SN - 2470-0010

VL - 98

JO - Physical Review D

JF - Physical Review D

IS - 11

M1 - 112009

ER -

Improved measurement of the longitudinal spin transfer to Λ and Λ hyperons in polarized proton-proton collisions at s =200 GeV

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