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Related papers: Top Quark Spin Polarization in e \gamma Collision

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We perform a comparative study of the reach of future $e^+e^-$ collider options for the scale of non-resonant new physics effects in the top quark sector, phrased in the language of higher-dimensional operators. Our focus is on the…

High Energy Physics - Phenomenology · Physics 2017-10-26 Christoph Englert , Michael Russell

Extensions of the Standard Model often predict new chiral interactions for top quark, which will contribute to top quark spin correlation and polarization in $t\bar{t}$ production at the LHC. In this work, under the constraints from the…

High Energy Physics - Phenomenology · Physics 2015-03-17 Junjie Cao , Lei Wu , Jin Min Yang

The production of top quark pairs accompanied by a hard gluon in $e^+e^-$ annihilation is studied including next-to-leading order corrections in the strong coupling. At leading order, the fraction r of $t\bar{t}g$ events with respect to all…

High Energy Physics - Phenomenology · Physics 2011-09-13 Arnd Brandenburg

Top quark production in the process $e^+e^- \rightarrow t\bar{t}$ at a future linear electron positron collider with polarized beams is a powerful tool to determine the scale of new physics. Studies at the $\ttbar$ threshold will allow for…

High Energy Physics - Experiment · Physics 2014-01-07 D. Asner , A. Hoang , Y. Kiyo , R. Pöschl , Y. Sumino , M. Vos

We investigate the interaction of strong color fields in the glasma stage of high-energy nuclear collisions with the spins of quarks and antiquarks. We employ the perturbative solution of the quantum kinetic theory for the spin transport of…

Nuclear Theory · Physics 2023-04-28 Avdhesh Kumar , Berndt Müller , Di-Lun Yang

Beam polarization at e+ e- linear colliders will be a powerful tool for high precision analyses. Often it is assumed that the full information from polarization effects is provided by polarization of the electron beam and no further…

High Energy Physics - Phenomenology · Physics 2007-05-23 Gudrid Moortgat-Pick , Herbert M. Steiner

Here, it is suggested that a four-point interaction of the tensor type may lead to spin polarization in quark matter at high density. It is found that the two-flavor superconducting phase and the spin polarized phase correspond to distinct…

Nuclear Theory · Physics 2014-05-07 Y. Tsue , J. da Providencia , C. Providencia , M. Yamamura , H. Bohr

We study anomalous $W^-W^+Z/\gamma$ couplings due to dimension-$6$ operators in the production process $e^-e^+ \to W^-W^+$ followed by semi-leptonic decay using polarizations and spin-spin correlations of $W$ bosons. The construction of…

High Energy Physics - Phenomenology · Physics 2023-05-03 Amir Subba , Ritesh K. Singh

A polarized $ep/eA$ collider (Electron--Ion Collider, or EIC), with polarized proton and light-ion beams and unpolarized heavy-ion beams with a variable center--of--mass energy $\sqrt{s} \sim 20$ to $\sim100$~GeV (upgradable to $\sim 150$…

We calculate the spin density matrix of the vector meson produced in e+e- annihilation at Z^0 pole. We show that the data imply a significant polarization for the antiquark which is created in the fragmentation process of the polarized…

High Energy Physics - Phenomenology · Physics 2009-12-31 Qing-hua Xu , Chun-xiu Liu , Zuo-tang Liang

A set of inclusive cross sections at zero rapidity is presented for p-pbar interactions at center of mass energy sqrt(s)=1.8 TeV. Six particle cross sections are corrected for secondary contributions from decays of higher mass resonances in…

The top quark is by far the most massive fundamental particle observed so far, and the study of its properties is interesting for several reasons ranging from its possible special role in electroweak symmetry breaking to its sensitivity to…

High Energy Physics - Experiment · Physics 2007-05-23 Gervasio Gomez

Vector-like quarks (VLQs) are attractive extensions to the Standard Model. They mix with the SM quarks and can lead to rich phenomenology. Determination of VLQ's interaction structure with the SM is then an important issue, which can be…

High Energy Physics - Phenomenology · Physics 2019-02-20 Hang Zhou , Ning Liu

By using the Nambu-Jona-Lasinio model with a tensor-type four-point interaction between quarks, it is shown that there exists a possibility of a spin polarized phase in quark matter at finite temperature and density. When there exists the…

High Energy Physics - Phenomenology · Physics 2017-03-14 Y. Tsue , J. da Providencia , C. Providencia , H. Matsuoka , M. Yamamura , H. Bohr

We present analytic results for first order radiative QCD corrections to e^+e^- annihilation processes into quarks and gluons under the special aspect of polarized final state particles. This aspect involves single-spin polarization, gluon…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Groote

In top quark production, the polarization of top quarks, decided by the chiral structure of couplings, is likely to be modified in the presence of any new physics contribution to the production. Hence the same is a good discriminator for…

High Energy Physics - Phenomenology · Physics 2019-09-25 Rohini Godbole , Monoranjan Guchait , Charanjit K. Khosa , Jayita Lahiri , Seema Sharma , Aravind H. Vijay

We analyze the capability of the next generation of linear electron--positron colliders to unravel the spin and couplings of excited leptons predicted by composite models. Assuming that these machines will be able to operate both in the…

High Energy Physics - Phenomenology · Physics 2014-11-17 O. J. P. Eboli , E. M. Gregores , J. C. Montero , S. F. Novaes , D. Spehler

We have studied the spin polarization of $\Lambda$ hyperons in heavy ion collisions at center-of-mass energies $\sqrt{s_{NN}} = 200$ GeV and $\sqrt{s_{NN}} = 5.02$ TeV carried out at RHIC and LHC colliders. We have calculated the mean spin…

Nuclear Theory · Physics 2024-07-25 Andrea Palermo , Eduardo Grossi , Iurii Karpenko , Francesco Becattini

The $e^+e^-\to\eta\gamma$ cross section has been measured in the center-of-mass energy range 1.07--2.00 GeV using the decay mode $\eta\to 3\pi^0$, $\pi^0\to \gamma\gamma$. The analysis is based on 36 pb$^{-1}$ of integrated luminosity…

The role of the top quark in completing the Standard Model quark sector is reviewed, along with a discussion of production, decay, and theoretical restrictions on the top quark properties. Particular attention is paid to the top quark as a…

High Energy Physics - Phenomenology · Physics 2009-09-29 S. Dawson