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Related papers: Spin effects in vector meson production at LEP

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The recently developed quantum mechanical string+${}^3P_0$ model of polarized quark fragmentation with pseudoscalar and vector meson production has been implemented in a stand alone Monte Carlo program. The simulation enables the detailed…

High Energy Physics - Phenomenology · Physics 2023-01-18 Albi Kerbizi , Xavier Artru , Anna Martin

The global spin alignment of vector mesons has been observed by the STAR collaboration at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). It provides a unique opportunity to probe the correlation between…

High Energy Physics - Phenomenology · Physics 2025-02-27 Jin-Hui Chen , Zuo-Tang Liang , Yu-Gang Ma , Xin-Li Sheng , Qun Wang

Based on the formalism presented in [1], we make a systematic study of spin polarizations of hadrons with different spins including vector mesons, spin-1/2 and spin-3/2 hyperons and spin correlations of hadron-hadron such as…

Nuclear Theory · Physics 2026-03-17 Ji-peng Lv , Zi-han Yu , Xiao-wen Li , Zuo-tang Liang

Collisions of twisted particles --- that is, non-plane-wave states of photons, electrons, or any other particle, equipped with a non-zero orbital angular momentum (OAM) with respect to its propagation direction --- offer novel ways to probe…

High Energy Physics - Phenomenology · Physics 2020-05-20 Igor P. Ivanov , Nikolai Korchagin , Alexandr Pimikov , Pengming Zhang

Linear polarization of gluons inside unpolarized hadrons affects the transverse momentum distribution of produced spin-0 particles, such as of the Higgs or (pseudo-)scalar quarkonium states at LHC. Despite the currently unknown amount of…

High Energy Physics - Phenomenology · Physics 2015-10-21 Daniël Boer

Multiple polarization observables must be measured to access the amplitude structure of pseudoscalar meson photoproduction off the proton. The hyperon-producing reactions are especially attractive to study, since the weak decays allow…

Nuclear Experiment · Physics 2008-11-26 Reinhard Schumacher

The analytic expressions for the production cross sections of polarized bottom and top quarks in $e^+e^-$ annihilation are explicitly derived at the one-loop order of strong interactions. Chirality-violating mass effects will reduce the…

High Energy Physics - Phenomenology · Physics 2015-06-25 J. G. K"orner , A. Pilaftsis , M. M. Tung

In hydrodynamic approach to relativistic heavy ion collisions, hadrons with nonzero spin, produced out of the hydrodynamic medium, can acquire polarization via spin-vorticity thermodynamic coupling mechanism. The hydrodynamical quantity…

Nuclear Theory · Physics 2018-03-14 Iurii Karpenko , Francesco Becattini

The spin alignment matrix element rho_{00} for the vector mesons K^{*0} and phi(1020) has been measured in RHIC at central rapidities. These measurements are consistent with the absence of polarization with respect to the reaction plane in…

High Energy Physics - Phenomenology · Physics 2009-12-22 Alejandro Ayala , Eleazar Cuautle , G. Herrera Corral , J. Magnin , Luis Manuel Montano

The quark spin effects are introduced for the first time in the string fragmentation routine of the Pythia 8 Monte Carlo event generator for the simulation of $e^+e^-$ annihilation to hadrons. To describe the spin effects the…

High Energy Physics - Phenomenology · Physics 2023-12-29 A. Kerbizi , L. Lönnblad , A. Martin

We study the fragmentation of a transversely polarized quark into a non collinear (k_T not= 0) spinless hadron and the fragmentation of an unpolarized quark into a non collinear transversely polarized spin 1/2 baryon. These nonperturbative…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Anselmino , D. Boer , U. D'Alesio , F. Murgia

The measurement of the angular distribution of leptons from the decay of a $W$, $Z$, $\gamma^{\ast}$, or $\Jpsi$ produced at high transverse momentum in hadronic collisions provides a detailed test of the production and decay mechanism of…

High Energy Physics - Phenomenology · Physics 2009-09-25 E. Mirkes , J. Ohnemus

Spin effects in exclusive and inclusive reactions provide an essential new dimension for testing QCD and unraveling hadron structure. Remarkable new experiments from SLAC, HERMES (DESY), and the Jefferson Laboratory present many challenges…

High Energy Physics - Phenomenology · Physics 2009-09-11 Stanley J. Brodsky

We develop a general framework for studying the spin alignment $\rho_{00}$ for flavorless vector mesons by using the gauge/gravity duality. Focusing on the dilepton production through vector meson decay, we derive the relation between…

High Energy Physics - Phenomenology · Physics 2024-03-13 Xin-Li Sheng , Yan-Qing Zhao , Si-Wen Li , Francesco Becattini , Defu Hou

$Z$ production at an $e^+e^-$ collider, associated with production of other particles, can be an accurate source of information of details of electroweak interactions, including possible interactions beyond the standard model. We discuss…

High Energy Physics - Phenomenology · Physics 2023-11-23 Kumar Rao , Saurabh D. Rindani , Priyanka Sarmah , Balbeer Singh

The influence of the electron spin degree of freedom on nonperturbative electron-positron pair production by high-energy proton impact on an intense laser field of circular polarization is analyzed. Predictions from the Dirac and…

High Energy Physics - Phenomenology · Physics 2011-01-17 Tim-Oliver Müller , Carsten Müller

The spin effect of electrons/positrons ($e^-$/$e^+$) and polarization effect of $\gamma$ photons are investigated in the interaction of two counter-propagating linearly polarized 10-PW-class laser pulses with a thin foil target. The…

The ATLAS, CMS and LHCb collaborations have reported data for the inclusive production of lepton pairs with invariant mass 80-100 GeV in pp collisions. We find the ATLAS data from at $\sqrt{s}$ =8 TeV shows an unexpected vortex-like…

High Energy Physics - Phenomenology · Physics 2026-05-06 A. Gautam , J. C. Martens , J. P. Ralston , G. Stejskal , J. D. Tapia Takaki

Spin-dependent quark densities, matrix elements of specific density operators in proton states of definite spin-polarization, indicate that the nucleon may harbor an infinite variety of non-spherical shapes. We show that these matrix…

Nuclear Theory · Physics 2008-11-26 Gerald A. Miller

Spin alignments of vector mesons and hyperons in relativistic heavy-ion collisions have been proposed as signals of the global polarization. The STAR experiment first observed the $\rm \Lambda$ polarization. Recently, the ALICE…

Nuclear Experiment · Physics 2021-05-26 Diyu Shen , Jinhui Chen , Zi-Wei Lin