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 $x$ carried by the active quark and the transverse momentum $|\vec k_T|$ for different values of skewness $\xi$ defined as the longitudinal momentum transferred to the proton as well as the total momentum $|\vec\Delta_T|$ 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 $\rm e^- p\rightarrow \nu_e \bar{t} \rightarrow \nu_e h \bar{q}(h\rightarrow b\bar{b})$ in the top-Higgs FCNC couplings at the LHeC with the electron beam energy of $E_{e}$ = 60 GeV and $E_{e}$ = 120 GeV, combination of a 7 TeV and 50 TeV proton beam. With the possibility of e-beam polarization ($p_{e}$ = 0, $\pm0.6$), 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 $\rm(t\to uh)$ 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 ($E_{p}$, $E_{e}$) = (7 TeV, 60 GeV), ($E_{p}$, $E_{e}$) = (7 TeV, 120 GeV), ($E_{p}$, $E_{e}$) = (50 TeV, 60 GeV) and ($E_{p}$, $E_{e}$) = (50 TeV, 120 GeV) beam energy and 1$\sigma$ 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 ($\rm tqh,\ q=u,\ c$). We probe the observability of the FCNC top-Higgs couplings through the processes $\rm e^- p\rightarrow \nu_e \bar{t} \rightarrow \nu_e h \bar{q}$ (signal.I) and $\rm \ e^- p \to \nu_e h b$ (singal.II) at the proposed electron proton (ep) colliders, where the Higgs boson decays to a $\rm b\bar{b}$ pair. We find that at the high luminosity (1 $\rm ab^{-1}$) ep colliders where the electrons have a polarisation of $\rm 80\%$ and electron energy is typical 60 GeV, the 2$\sigma$ upper limit on $\rm Br(t\to uh)$ are $0.15\times 10^{-2}$($2.9\times 10^{-4}$) at the 7TeV@LHeC(50TeV@FCC-eh) for signal.I and $0.15\times 10^{-2}$($2.2\times 10^{-4}$) 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 $8.7\%$($29.4\%$) if the electron beam change from 60GeV to 50(40) GeV at the 7TeV LHeC, and $16.8\%$($19.8\%$) at the 50 TeV FCC-eh.Comment: 8 figures. 4 tables. 26 page

Investigation of intracavity phase interferometry applied to nano-metrology

Intracavity phase interferometry is sensing technique developed at UNM, in which a physical quantity to be measured is put as integral part of a mode-locked laser. It relies on the fact that any intracavity phase shift of an intracavity pulse will result in a frequency change of the whole pulse train. The implementations of IPI requires the operation of a mode-locked laser in which two pulses circulate independently, i.e. with no phase coupling between them. IPI has been demonstrated with a variety of laser systems, to detect either non-reciprocal effects (such as rotation, magnetic field), or phase changes that can be made periodic at the repetition rate of the laser cavity. The purpose of this work is to study the feasibility of applying this technique to the measurement of non-periodic (i.e. slow) changes in optical path. The new concept to measure sub-nanometer displacement uses an optoelectronic modulator (EOM) inside the cavity. The operation of the mode-locked laser after insertion of such an element in its cavity is analyzed. Several laser systems have been tried for the implementation of IPI. Two of them are presented in this thesis. The first one is a Nd:YVO4 laser, mode-locked by a multiple quantum wells (MQW) saturable absorber. The presence of a solid state saturable absorber introduced a dead band in the beat note response of the system. A new coupling between group and phase velocity was discovered experimentally, and explained through simulation. This coupling affects negatively the operation of the system, since the repetition rate is no longer a reliable fixed quantity. The coupling could be eliminated by replacing the MQW with a dye jet absorber. A first demonstration of a slow optical path change (in the nm range) was made. The system that appeared at first the most promising is the intracavity optical parametric oscillator (OPO) synchronously pumped by a mode-locked Ti:Sapphire lasers. Bringing the unstable behavior of that laser under control proved considerably more difficult than anticipated, and led to an extensive theoretical analysis of the laser. The instabilities arise from both intensity and phase fluctuations in the OPO pulse train. We simulate the second order nonlinear interactions taking place inside the nonlinear crystal of the OPO, using a new approach in the frequency domain, valid down to a few optical cycles, and taking into account the dispersion of the crystal to all orders. Phase mismatched processes draw our attention as they introduce large effective nonlinear refractive indices (creating self-phase- and crossphase- modulation) that result in a coupling of intensity and phase instabilities. A full numerical model of coupled Ti:Sapphire and OPO cavities is established by parameterizing the gain, loss, dispersion and nonlinearities. The pulse evolution of both Ti:Sapphire and OPO is examined at each cavity round trip using the ABCD matrix method in temporal domain invented in this dissertation. The simulation reproduces the observed unstable operation. However, islands of stability are found. That is an operation observed to be stable against perturbation of any of the parameters