Accessing Quark Helicity through Dihadron Studies

Matevosyan, Hrayr H.; Kotzinian, A.M.; Thomas, A. W.

doi:10.1103/physrevlett.120.252001

Cited by 20 publications

(23 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In particular, as we first noted in Ref. [6], the proposed asymmetry for accessing G ⊥ 1 should vanish. There, we also proposed two new measurements of asymmetries involving G ⊥ 1 , one in electron-positron annihilation and one in SIDIS processes.…”

supporting

confidence: 53%

See 1 more Smart Citation

Accessing quark helicity in $e^+e^-$ and SIDIS via dihadron correlations.

Matevosyan¹

2018

Proceedings of XXVI International Workshop on Deep-Inelastic Scattering and Related Subjects — PoS(DIS2018)

View full text Add to dashboard Cite

The correlation between the longitudinal polarization of a fragmenting quark and the transverse momenta of the produced hadrons was predicted over two decades ago. Nevertheless, experimental searches in the electron-positron annihilation process, both through the so-called jet handedness measurements by the SLD Collaboration and more recently via the measurements of the azimuthal asymmetry containing the helicity-dependent dihadron fragmentation function (DiFF) by the BELLE Collaboration, did not yield a signal. We will first discuss our recent explanation of the zero result at BELLE, and the two new methods for accessing the helicity-dependent DiFFs both in the electron-positron annihilation experiments, and in the semi-inclusive deep inelastic scattering (SIDIS) experiments with a longitudinally polarized target. We will also for the first time describe yet another, new method for accessing the helicity-dependent DiFFs in SIDIS using polarized beam asymmetry. Finally, we will present a new Monte Carlo calculation of the specific Fourier moments of the helicity-dependent DiFF entering in to the new asymmetries, performed within the extended quark-jet model, and compare the results to those for the interference DiFF.

show abstract

supporting

confidence: 53%

“…A new asymmetry to measure G ⊥ 1 has been recently proposed in Ref [6], where the weight includes both the azimuthal angle and the magnitude of q T q 2 T 3 sin(ϕ qR ) sin(ϕ qR ) + cos(ϕ qR ) cos(ϕ qR )…”

mentioning

confidence: 99%

Accessing quark helicity in $e^+e^-$ and SIDIS via dihadron correlations.

Matevosyan¹

2018

Proceedings of XXVI International Workshop on Deep-Inelastic Scattering and Related Subjects — PoS(DIS2018)

View full text Add to dashboard Cite

show abstract

“…(3.15) extracts a product of the helicity-dependent DiFF G ⊥ 1 with the "collinear" helicity FF G 1L when measuring the longitudinal polarization of the Λ. Such a measurement will complement the previously proposed measurements of G ⊥ 1 in e + e − annihilation and SIDIS [20,60], aimed at testing the universality of G ⊥ 1 . The transverse polarization-dependent modulation in Eq.…”

Section: Discussionmentioning

confidence: 91%

“…Recently, we proposed two new measurements [20] of the quark helicity dependent DiFF G ⊥ 1 , both in SIDIS with two final state detected hadrons and two back-to-back hadron pair production in e + e − annihilation. The chiral-even nature of G ⊥ 1 entails that in SIDIS it couples to the well-determined quark unpolarized and helicity PDFs [21].…”

Section: Introductionmentioning

confidence: 99%

Semi-inclusive back-to-back production of a hadron pair and a single hadron in e+e− annihilation

Matevosyan

Kotzinian

Thomas

2018

J. High Energ. Phys.

Self Cite

View full text Add to dashboard Cite

Inclusive hadron production in e + e − annihilation has long been used to study both single hadron fragmentation functions (FF) and dihadron fragmentation functions (DiFF). In particular, the polarized DiFFs can be accessed in electron-positron annihilation by measuring azimuthal correlations between two back-to-back pairs of hadrons in the center of mass system, where the relevant structure functions can be expressed as convolutions of two (polarized) DiFFs. Here we explore the advantages of measuring the inclusive back-to-back production of a single hadron on one side against a hadron pair on the opposite side of the detector in two jet events. The leading twist cross section for this process contains convolutions of the corresponding single hadron FFs on one side and the DiFFs for the hadron pair on the other side, which furnishes several interesting new opportunities. A measurement of the unpolarized cross section with a number of different types of observed hadrons will help in untangling the quark flavor dependence of the unpolarized DiFFs, when the results are analyzed together with the inclusive measurements of dihadron pairs, such as those recently performed by the BELLE collaboration. Even more interesting, with a polarized hyperon on one side we can study the quark spin-dependent DiFFs of an unpolarized hadron pair on the other side. This, in turn, will allow us to test the universality of the spin-dependent DiFFs entering the cross sections of electron-positron annihilation and semi-inclusive deep inelastic scattering processes.

show abstract

“…Such new weight has been recently proposed in Ref. [41], that also involves the azimuthal angle ϕ q = ϕ 1 + π of q T to exactly cancel out the contributions from the unpolarized term in the cross section:…”

Section: B the Asymmetry For The Helicity Dependent Diffmentioning

confidence: 99%

Semi-inclusive production of two back-to-back hadron pairs in e+e− annihilation revisited

et al. 2018

Self Cite

View full text Add to dashboard Cite

The cross section for back-to-back hadron pair production in e þ e − annihilation provides access to the dihadron fragmentation functions (DiFF) needed to extract nucleon parton distribution functions from the semi-inclusive deep inelastic scattering (SIDIS) experiments with two detected final state hadrons. Particular attention is given to the so-called interference DiFF (IFF), which makes it possible to extract the transversity parton distribution of the nucleon in the collinear framework. However, previously unnoticed discrepancies were recently highlighted between the definitions of the IFFs appearing in the collinear kinematics when reconstructed from DiFFs entering the unintegrated fully differential cross sections of SIDIS and e þ e − annihilation processes. In this work, to clarify this problem we re-derive the fully differential cross section for e þ e − annihilation at the leading-twist approximation. We find a mistake in the definition of the kinematics in the original expression that systematically affects a subset of terms and that leads to two significant consequences. First, the discrepancy between the IFF definitions in the cross sections for SIDIS and e þ e − annihilation is resolved. Second, the previously derived azimuthal asymmetry for accessing the helicity dependent DiFF G ⊥ 1 in e þ e − annihilation vanishes, which explains the nonobservation of this asymmetry in the recent experimental searches by the BELLE collaboration. We discuss the recently proposed alternative option to extract G ⊥ 1 .

show abstract

Accessing Quark Helicity through Dihadron Studies

Cited by 20 publications

References 19 publications

Accessing quark helicity in $e^+e^-$ and SIDIS via dihadron correlations.

Accessing quark helicity in $e^+e^-$ and SIDIS via dihadron correlations.

Semi-inclusive back-to-back production of a hadron pair and a single hadron in e+e− annihilation

Semi-inclusive production of two back-to-back hadron pairs in e+e− annihilation revisited

Contact Info

Product

Resources

About