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1. chinaXiv:201711.00276 [pdf]

DPABI: Data Processing & Analysis for (Resting-State) Brain Imaging

Chao-Gan Yan; Xin-Di Wang; Xi-Nian Zuo; Yu-Feng Zang
Subjects: Psychology >> Applied Psychology

Brain imaging efforts are being increasingly devoted to decode the functioning of the human brain. Among neuroimaging techniques, resting-state fMRI (R-fMRI) is currently expanding exponentially. Beyond the general neuroimaging analysis packages (e.g., SPM, AFNI and FSL), REST and DPARSF were developed to meet the increasing need of user-friendly toolboxes for R-fMRI data processing. To address recently identified methodological challenges of R-fMRI, we introduce the newly developed toolbox, DPABI, which was evolved from REST and DPARSF. DPABI incorporates recent research advances on head motion control and measurement standardization, thus allowing users to evaluate results using stringent control strategies. DPABI also emphasizes test-retest reliability and quality control of data processing. Furthermore, DPABI provides a user-friendly pipeline analysis toolkit for rat/monkey R-fMRI data analysis to reflect the rapid advances in animal imaging. In addition, DPABI includes preprocessing modules for task-based fMRI, voxel-based morphometry analysis, statistical analysis and results viewing. DPABI is designed to make data analysis require fewer manual operations, be less time-consuming, have a lower skill requirement, a smaller risk of inadvertent mistakes, and be more comparable across studies. We anticipate this open-source toolbox will assist novices and expert users alike and continue to support advancing R-fMRI methodology and its application to clinical translational studies.

submitted time 2017-11-06 Hits9534Downloads3281 Comment 0

2. chinaXiv:201711.00277 [pdf]

Linear trend of resting-state fMRI time series

Xin-Di Wang; Chao-Gan Yan; Yu-Feng Zang
Subjects: Psychology >> Applied Psychology

Although爈inear trend removing has often been implemented as a routine preprocessing step in resting-state functional magnetic resonance imaging (RS-fMRI) data analysis, the爏patial distribution爋f the magnitude of linear trend is still unclear. Further, it is interesting whether there will be any difference of the linear trend magnitude between different resting-states. For the first aim, we analyzed 5 RS-fMRI datasets from 5 different scanners (namely Beijing-Simens-3T, Cambridge-Siemens-3T, CCBD-GE750-3T, Milwaukee-GE-3T, and Oulu-GE-1.5T). One-sample t-tests on the regression coefficient (i.e., the magnitude of linear trend) were performed for each datasets. For the second aim, we used 2 datasets in each of which different states were compared, one containing eyes-open resting-state (EO-RS) vs. eyes-closed resting-state (EC-RS) and the other containing two steady-state tasks, i.e.,爎eal-time finger force feedback?RT-FFF) and sham finger force feedback (S-FFF) tasks. Paired t-tests were performed between EO-RS and EC-RS, and between RT-FFF and S-FFF. One-sample t-tests showed that the spatial pattern of linear trend of RS-fMRI time series were quite different between different manufactures. The 3T SIEMENS scanners showed positive linear trend in almost all part of the brain, while GE scanners showed primarily negative linear trend in most part of the brain. Paired t-tests showed some differences between paired conditions; differences between EO-RS and EC-RS were mainly in cuneus and eyeballs, and differences between RT-FFF and S-FFF were found in the thalamus, anterior cingulate gyrus, and right sensorimotor cortex. The current study indicated that, while the manufacturer-dependent linear trend of RS-fMRI time series were mostly scanner-related noise, the linear trend may also be physiological noise (eyeballs) or even physiologically meaningful, especially during steady-state tasks.

submitted time 2017-11-06 Hits6971Downloads1808 Comment 0

3. chinaXiv:201609.01016 [pdf]

Next-to-Leading Order Differential Cross Sections for J/ψ,ψ(2S), and Υ Production in Proton-Proton Collisions at a Fixed-Target Experiment Using the LHC Beams (AFTER@LHC)

Yu Feng; Jian-Xiong Wang
Subjects: Physics >> Nuclear Physics

Using nonrelativistic QCD (NRQCD) factorization, we calculate the yields for?J/ψ,?ψ(2S)?and?Υ(1S)hadroproduction at?s√=?72 GeV and 115 GeV including the next-to-leading order QCD corrections. Both these center-of-mass energies correspond to those obtained with 7~TeV and 2.76~TeV nucleon beam impinging a fixed target. We study the cross section integrated in?pt?as a function of the rapidity as well as the?pt?differential cross section in the central rapidity region. Using different NLO fit results of the NRQCD long-distance matrix elements, we evaluate a theoretical uncertainty which is certainly much larger than the projected experimental uncertainties with the expected 20 fb?1?to be collected per year with AFTER@LHC.

submitted time 2016-09-14 Hits535Downloads307 Comment 0

4. chinaXiv:201609.01012 [pdf]

Potential of Geo-neutrino Measurements at JUNO

Ran HAN; Yu-Feng LI; Liang ZHAN; William F McDonough; Jun CAO; Livia Ludhova
Subjects: Physics >> Nuclear Physics

The flux of geoneutrinos at any point on the Earth is a function of the abundance and distribution of radioactive elements within our planet. This flux has been successfully detected by the 1-kt KamLAND and 0.3-kt Borexino detectors with these measurements being limited by their low statistics. The planned 20-kt JUNO detector will provide an exciting opportunity to obtain a high statistics measurement, which will provide data to address several questions of geological importance. This paper presents the JUNO detector design concept, the expected geo-neutrino signal and corresponding backgrounds. The precision level of geo-neutrino measurements at JUNO is obtained with the standard least-squares method. The potential of the Th/U ratio and mantle measurements is also discussed.

submitted time 2016-09-14 Hits799Downloads442 Comment 0

5. chinaXiv:201609.00978 [pdf]

Neutrino Oscillation Probabilities in Matter with Direct and Indirect Unitarity Violation in the Lepton Mixing Matrix

Yu-Feng Li; Shu Luo
Subjects: Physics >> Nuclear Physics

In the presence of both direct and indirect unitarity violation in the lepton mixing matrix, we derive a complete set of series expansion formulas for neutrino oscillation probabilities in matter of constant density. Expansions in the mass hierarchy parameter?α≡Δm221/Δm231?and those unitarity violation parameters?s2ij?(for i = 1, 2, 3 and j = 4, 5, 6) up to the first order are studied in this paper. We analyse the accuracy of the analytical series expansion formulas in different regions of L / E. A detailed numerical analysis is also performed, of which the different effects of the direct and the indirect unitarity violation are particularly emphasized. We also study in this paper the summed?να→νe,ν,τprobabilities, whose deviation from the unity provides a definite signal of the unitarity violation.

submitted time 2016-09-14 Hits943Downloads529 Comment 0

6. chinaXiv:201609.00958 [pdf]

Electromagnetic neutrinos in laboratory experiments and astrophysics

Carlo Giunti; Konstantin A. Kouzakov; Yu-Feng Li; Alexey V. Lokhov; Alexander I. Studenikin; Shun Zhou
Subjects: Physics >> Nuclear Physics

An overview of neutrino electromagnetic properties, which open a door to the new physics beyond the Standard Model, is given. The effects of neutrino electromagnetic interactions both in terrestrial experiments and in astrophysical environments are discussed. The experimental bounds on neutrino electromagnetic characteristics are summarized. Future astrophysical probes of electromagnetic neutrinos are outlined.

submitted time 2016-09-13 Hits1323Downloads774 Comment 0

7. chinaXiv:201609.00934 [pdf]

Long-range self-interacting dark matter in the Sun

Jing Chen; Zheng-Liang Liang; Yue-Liang Wu; Yu-Feng Zhou
Subjects: Physics >> Nuclear Physics

We investigate the implications of the long-rang self-interaction on both the self-capture and the annihilation of the self-interacting dark matter (SIDM) trapped in the Sun. Our discussion is based on a specific SIDM model in which DM particles self-interact via a light scalar mediator, or Yukawa potential, in the context of quantum mechanics. Within this framework, we calculate the self-capture rate across a broad region of parameter space. While the self-capture rate can be obtained separately in the Born regime with perturbative method, and the classical limits with the Rutherford formula, our calculation covers the gap between in a non-perturbative fashion. Besides, the phenomelogy of both the Sommerfeld-enhanced s- and p-wave annihilation of the solar SIDM is also involved in our discussion. Moreover, by combining the analysis of the Super-Kamiokande (SK) data and the observed DM relic density, we constrain the nuclear capture rate of the DM particles in the presence of the dark Yukawa potential. The consequence of the long-range dark force on probing the solar SIDM turns out to be significant if the force-carrier is much lighter than the DM particle, and a quantitative analysis is provided.

submitted time 2016-09-13 Hits760Downloads455 Comment 0

8. chinaXiv:201609.00911 [pdf]

Detection Prospects of the Cosmic Neutrino Background

Yu-Feng Li
Subjects: Physics >> Nuclear Physics

The existence of the cosmic neutrino background (CnuB) is a fundamental prediction of the standard Big Bang cosmology. Although current cosmological probes provide indirect observational evidence, the direct detection of the CnuB in a laboratory experiment is a great challenge to the present experimental techniques. We discuss the future prospects for the direct detection of the CnuB, with the emphasis on the method of captures on beta-decaying nuclei and the PTOLEMY project. Other possibilities using the electron-capture (EC) decaying nuclei, the annihilation of extremely high-energy cosmic neutrinos (EHEC\nus) at the Z-resonance, and the atomic de-excitation method are also discussed in this review.

submitted time 2016-09-13 Hits911Downloads526 Comment 0

9. chinaXiv:201609.00900 [pdf]

Energy dependence of direct-quarkonium production in $pp$ collisions from fixed-target to LHC energies: complete one-loop analysis

Yu Feng; Jean-Philippe Lansberg; Jian-XiongWang
Subjects: Physics >> Nuclear Physics

We compute the energy dependence of the P_T-integrated cross section of directly produced quarkonia in pp collisions at next-to-leading order (NLO), namely up to alpha_s^3, within nonrelativistic QCD (NRQCD). Our analysis is based on the idea that the P_T-integrated and the P_T-differential cross sections can be treated as two different observables. The colour-octet NRQCD parameters needed to predict the P_T-integrated yield can thus be extracted from the fits of the P_T-differential cross sections at mid and large P_T. For the first time, the total cross section is evaluated in NRQCD at full NLO accuracy using the recent NLO fits of the P_T-differential yields at RHIC, the Tevatron and the LHC. Both the normalisation and the energy dependence of the J/psi, psi' and Upsilon(1S), we obtained, are in disagreement with the data irrespective of the fit method. The same is true if one uses CEM-like colour-octet NRQCD parameters. If, on the contrary, one disregards the colour-octet contribution, the existing data in the TeV range are well described by the alpha_s^3 contribution in the colour-singlet model --which, at alpha_s^4, however shows an unphysical energy dependence. A similar observation is made for eta(c,b). This calls for a full NNLO or for a resummation of the initial-state radiation in this channel. In any case, past claims that colour-octet transitions are dominantly responsible for low-P_T quarkonium production are not supported by our results. This may impact the interpretation of quarkonium suppression in high-energy proton-nucleus and nucleus-nucleus collisions.

submitted time 2016-09-13 Hits545Downloads287 Comment 0

10. chinaXiv:201609.00899 [pdf]

An updated study of $\Upsilon$ production and polarization at the Tevatron and LHC

Yu Feng; Bin Gong; Lu-Ping Wan; Jian-Xiong Wang
Subjects: Physics >> Nuclear Physics

Following the nonrelativistic QCD factorization scheme, by taking latest available measurement on?χb(3P)?into consideration, we present an updated study on the yield and polarization of?Υ(1S,2S,3S)?hadroproduction, and the fractions of?χb(mP)?feed-down in?Υ(nS)?production at QCD next-to-leading order. In the fitting, three schemes are applied with different choice of?χb(mP)?feed-down ratios and NRQCD factorization scale. The results can explain the measurements on yield very well as in our previous work. The polarization puzzle to?Υ(3S)?is now solved by considering the?χb(3P)?feed-down contributions. The ratio of?σ[χb2(1P)]/σ[χb1(1P)]?measurements from CMS can also be reproduced in our prediction. Among the different schemes, the results show little difference, but there are sizeable difference for the fitted long-distance color-octet matrix elements. It may bring large uncertainty when the values are applied in other experiments such as in?ee,?ep?colliders.

submitted time 2016-09-13 Hits563Downloads335 Comment 0

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