6,315 research outputs found
T-odd generalized and quasi transverse momentum dependent parton distribution in a scalar spectator model
Generalized transverse momentum dependent parton distributions (GTMDs), as
mother funtions of transverse momentum dependent parton distributions (TMDs)
and generalized parton distributions (GPDs), encode the most general parton
structure of hadrons. We calculate four twist-two time reversal odd GTMDs of
pion in a scalar spectator model. We study the dependence of GTMDs on the
longitudinal momentum fraction carried by the active quark and the
transverse momentum for different values of skewness defined
as the longitudinal momentum transferred to the proton as well as the total
momentum transferred to the proton. In addition, the
quasi-TMDs and quasi-GPDs of pion have also been investigated in this paper
Searches for the Anomalous FCNC Top-Higgs Couplings with Polarized Electron Beam at the LHeC
In this paper, we study the single top and Higgs associated production in the top-Higgs FCNC couplings at the LHeC with the electron beam
energy of = 60 GeV and = 120 GeV, combination of a 7 TeV and 50
TeV proton beam. With the possibility of e-beam polarization ( = 0,
), we distinct the Cut-based method and the Multivariate Analysis (MVA)
based method, and compare with the current experimental and theoretical limits.
It is shown that the branching ratio Br can be probed to 0.113
(0.093) , 0.071 (0.057) , 0.030 (0.022) and 0.024 (0.019)
with the Cut-based (MVA-based) analysis at (, ) = (7 TeV, 60
GeV), (, ) = (7 TeV, 120 GeV), (, ) = (50 TeV, 60
GeV) and (, ) = (50 TeV, 120 GeV) beam energy and 1
level. With the possibility of e-beam polarization, the expected limits can be
probed down to 0.090 (0.073) , 0.056 (0.045) , 0.024 (0.018) and
0.019 (0.015) , respectively.Comment: 13pages, 5 figures. Advance in High Energy Physic
Exploring the Anomalous Top-Higgs FCNC Couplings at the electron proton colliders
We perform an updated analysis on the searches for the anomalous FCNC Yukawa
interactions between the top quark, the Higgs boson, and either an up or charm
quark (). We probe the observability of the FCNC top-Higgs
couplings through the processes (signal.I) and (singal.II) at the
proposed electron proton (ep) colliders, where the Higgs boson decays to a pair. We find that at the high luminosity (1 ) ep
colliders where the electrons have a polarisation of and electron
energy is typical 60 GeV, the 2 upper limit on are
() at the 7TeV@LHeC(50TeV@FCC-eh) for
signal.I and () for signal.II. We also
give an estimate on how the sensitivity (take signal.I as examples) would
change when we reduce the electron beam energy from 60 GeV to 50 GeV or even 40
GeV due to the cost reason. The conclusion is that the discovery potential
reduce () if the electron beam change from 60GeV to 50(40) GeV
at the 7TeV LHeC, and () at the 50 TeV FCC-eh.Comment: 8 figures. 4 tables. 26 page
A study of ion acceleration, asymmetric optical pumping and low frequency waves in two expanding helicon plasmas
This work concerns measurements of parallel ion flow, optical pumping, and low frequency waves in expanding plasmas generated by two different helicon plasma sources. The measurements confirm numerical predictions of the formation of a current-free double layer in a region of diverging magnetic field. With laser-induced fluorescence (LIF), the double layer structure in both helicon plasma sources was investigated through measurements of the bulk parallel ion flow speed. Both double layers have a total potential drop of 3-4 kTe and length scales smaller than ion-neutral mean-free-path. A stronger double layer, with a potential drop of βΌ 6kTe , was created in a uniform magnetic field region with a plasma limiting aperture plate. During the investigations of ion acceleration in expanding plasmas, a new phenomenon, asymmetrical optical pumping (AOP) due to the acceleration of ions in magnetic field gradient, was observed. The signature of AOP is a difference in the LIF emission amplitude from a pair of Zeeman-split ion states. A model that reproduces the dependence of the AOP on magnetic-field and ion-velocity gradients is described. With magnetic fluctuation probes, low frequency, transverse, electromagnetic waves were also identified in the expanding helicon plasma. The wave is localized to the vicinity of the maximum plasma density gradient and appears only at low neutral pressure. Based on the scaling of the wave frequency and amplitude with magnetic field strength, the wave was identified as the resistive drift Alfven wave
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