arXiv subjects

Hao Sun

Publications and source records attributed to Hao Sun.

536 records · Page 30Linked to original sources

arXiv2014

NLO QCD corrections to Single Top and W associated production at the LHC with forward detector acceptances

In this paper we study the Single Top and W boson associated photoproduction via the main reaction $\rm pp\rightarrow pγp\rightarrow pW^{\pm}t+Y$ at the 14 TeV Large Hadron Collider (LHC) up to next-to-leading order (NLO) QCD level assuming a typical LHC multipurpose forward detector. We use the Five-Flavor-Number Schemes (5FNS) with massless bottom quark assumption in the whole calculation. Our results show that the QCD NLO corrections can reduce the scale uncertainty. The typical K-factors are in the range of 1.15 to 1.2 which lead to the QCD NLO corrections of 15$%$ to 20$%$ correspond to the leading-order (LO) predictions with our chosen parameters.

hep-ph↗

arXiv2014

Experiment of Diffuse Reflection Laser Ranging to Space Debris and Data Analysis

Space debris has been posing a serious threat to human space activities and is needed to be measured and cataloged. As a new technology of space target surveillance, the measurement accuracy of DRLR (Diffuse Reflection Laser Ranging) is much higher than that of microwave radar and electro-optical measurement. Based on laser ranging data of space debris from DRLR system collected at SHAO (Shanghai Astronomical Observatory) in March-April 2013, the characteristics and precision of the laser ranging data are analyzed and its applications in OD (Orbit Determination) of space debris are discussed in this paper, which is implemented for the first time in China. The experiment indicates that the precision of laser ranging data can reach 39cm-228cm. When the data is sufficient enough (4 arcs of 3 days), the orbit accuracy of space debris can be up to 50m.

physics.space-ph↗

arXiv2014

Dark Matter Searches in Jet plus Missing Energy in $\rm γp$ collision at CERN LHC

In this paper, we investigate the $\rm γp$ photoproduction of jet plus missing energy signal to set limits on the couplings of the fermionic dark matter to the quarks at the LHC via the main reaction $\rm pp\rightarrow pγp\rightarrow p χχj$. We assume a typical LHC multipurpose forward detectors and work in a model independent Effective Field Theory framework. Typically, when we do the background analysis, we also include their corresponding Single Diffractive (SD) productions. Our result shows that by requiring a $5σ$ ($\rm S/\sqrt{B} \geq 5$) signal deviation, with an integrated luminosity of $\rm {\cal L} = 200 fb^{-1}$, the lower bounds of WIMP masses scale can be detected up to $\rm Λ$ equal 665.5, 808.9 and 564.0 GeV for the forward detector acceptances $ξ_1$, $ξ_2$, and $ξ_3$, respectively, where $0.0015<ξ_1<0.5$, $0.1<ξ_2<0.5$ and $0.0015<ξ_3<0.15$.

hep-ph↗

arXiv2014

Large Extra Dimension effects through Light-by-Light Scattering at the CERN LHC

Observing light-by-light scattering at the Large Hadron Collider (LHC) has received quite some attention and it is believed to be a clean and sensitive channel to possible new physics. In this paper, we study the diphoton production at the LHC via the process $\rm pp\rightarrow pγγp\rightarrow pγγp$ through graviton exchange in the Large Extra Dimension (LED) model. Typically, when we do the background analysis, we also study the Double Pomeron Exchange (DPE) of $γγ$ production. We compare its production in the quark-quark collision mode to the gluon-gluon collision mode and find that contributions from the gluon-gluon collision mode are comparable to the quark-quark one. Our result shows, for extra dimension $δ=4$, with an integrated luminosity $\rm {\cal L} = 200 fb^{-1}$ at the 14 TeV LHC, that diphoton production through graviton exchange can probe the LED effects up to the scale $\rm M_S=5.06 (4.51, 5.11) TeV$ for the forward detector acceptance $ξ_1 (ξ_2, ξ_3)$, respectively, where $0.0015<ξ_1<0.5$, $0.1<ξ_2<0.5$ and $0.0015<ξ_3<0.15$.

hep-ph↗

arXiv2014

Probe Anomalous $tqγ$ couplings through Single Top Photoproduction at the LHC

In this work we study the constraints on the anomalous $tqγ$ ($q=u$, $c$) couplings by photon-produced leading single top production and single top jet associated production through the main reaction $pp\rightarrow pγp\rightarrow pt\rightarrow pW(\rightarrow\ell ν_\ell) b+X$ and $pp\rightarrow pγp\rightarrow ptj\rightarrow pW(\rightarrow\ell ν_\ell) bj+X$ assuming a typical LHC multipurpose forward detectors in a model independent effective lagrangian approach. Our results show that: for the typical detector acceptance $0.0015<ξ_1<0.5$, $0.1<ξ_2<0.5$ and $0.0015<ξ_3<0.15$ with a luminosity of 2 $\rm{fb}^{-1}$, the lower bounds of $κ_{tqγ}$ through leading single top channel (single top jet channel) are 0.0096 (0.0115), 0.0162 (0.0152) and 0.0098 (0.0122), respectively, correspond to $\rm{Br}(t\rightarrow qγ)\sim 3\times 10^{-5}$. With a luminosity of 200 $\rm{fb}^{-1}$, the lower bounds of $κ_{tqγ}$ are 0.0031 (0.0034), 0.0051 (0.0047) and 0.0031(0.0038), respectively, correspond to $\rm{Br}(t\rightarrow qγ)\sim 4\times 10^{-6}$. We conclude that both channels can be used to detect such anomalous $tqγ$ couplings and the detection sensitivity on $κ_{tqγ}$ can be improved.

hep-ph↗

arXiv2014

Pluricanonical maps of varieties of Albanese fiber dimension two

In this paper we prove that for any smooth projective variety of Albanese fiber dimension two and of general type, the 6-canonical map is birational. And we also show that the 5-canonical map is birational for any such variety with some geometric restrictions.

math.AG↗

arXiv2014

Precise photoproduction of the charged top-pions at the LHC with forward detector acceptances

We study the photoproduction of the charged top-pion predicted by the top triangle moose ($TTM$) model (a deconstructed version of the topcolor-assisted technicolor $TC2$ model) via the processes $pp\rightarrow p γp \rightarrow π^\pm_t t +X$ at the 14 $TeV$ Large Hadron Collider ($LHC$) including next-to-leading order ($NLO$) $QCD$ corrections. Our results show that the production cross sections and distributions are sensitive to the free parameters $\sinω$ and $M_{π_t}$. Typical $QCD$ correction value is $7\% \sim 11\%$ and does not depend much on $\sinω$ as well as the forward detector acceptances.

hep-ph↗

arXiv2013

Combinatorial symmetry of line arrangements and applications

We introduce an algorithm that exploits a combinatorial symmetry of an arrangement in order to produce a geometric reflection between two disconnected components of its moduli space. We apply this method to disqualify three real examples found in previous work by the authors from being Zariski pairs. Robustness is shown by its application to complex cases, as well.

math.AG↗

arXiv2013

Cohomological support loci of varieties of Albanese fiber dimension one

Let $X$ be a smooth projective variety of Albanese fiber dimension 1 and of general type. We prove that the translates through 0 of all components of $V^0(ω_X)$ generate $\Pic^0(X)$. We then study the pluricanonical maps of $X$. We show that $|4K_X|$ induces a birational map.

math.AG↗

arXiv2012

Enhancement of Loop induced 125GeV Higgs pair production through Large-Extra-Dimensions model at the LHC

Based on the analysis of 5 fb^-1 of data at the LHC, the ATLAS and CMS collaborations have presented evidence for a Higgs boson with a mass in the 125 GeV range. We consider the 125 GeV neutral Higgs pair production process in the context of large-extra-dimensions(LED) model including the Kaluza-Klein(KK) excited gravitons at the LHC. We take into account the LED effects coming from gluon-gluon fusion and quark-antiquark collision channels as well as their corresponding next-to-leading order(NLO) QCD loop induced corrections. We analyse their impacts on both the total cross section and some key distributions. Indeed,pp -> HH has the clear advantage of a lower standard model(SM) background compare to process like pp -> jj, though its SM prediction is very small, it is shown that the LED model raises the cross section of Higgs pair production compare to its SM prediction and enhance the transverse momentum(pHT) and invariant mass(MHH) Distributions especially at high scales of pH T and MHH. By including the NLO QCD loop corrections, the scale dependence of total cross section can be reduced obviously. Choose suitable decay modes like HH -> bbrr or HH -> bbmumu and some simple cuts, we can strongly reduce the SM background but keep most of the LED effects, leading Higgs pair production a promising channel to search LED effects.

hep-ph↗

arXiv2012

Constraints on large-extra-dimensions model through 125 GeV Higgs pair production at the LHC

hep-ph↗

arXiv2012

Flavor changing top quark decay and bottom-strange production in the littlest Higgs model with T-parity

Flavor changing effects on the processes \tch, \eebs, \eebsh and \ppbs in the LHT model are investigated in this paper. We calculate the one-loop level contributions from the T-parity odd mirror quarks and gauge bosons. The results show that the top quark rare decay \tch in the LHT model can be significantly enhanced relative to that in the SM. The $b\bar{s}$ production at linear colliders in the LHT model can enhance the SM cross section a lot and reach 0.1 fb in some parameter space allowed in the experiment. But the heavy gauge boson and mirror fermion loops have small contribution to the processes \ppbs and \eebsh. So the LHT effect on \eebs might be detected at future linear colliders, while it's too small to be seen for the \eebsh and \ppbs processes at future linear colliders and LHC.

hep-ph↗

arXiv2012

Neutral Triple Gauge Boson production in the large extra dimensions model at linear colliders

We consider the neutral triple gauge boson production process in the context of large extra dimensions (LED) model including the Kaluza-Klein (KK) excited gravitons at future linear colliders, say ILC(CLIC). We consider $γγγ, γγZ, γZ Z$ and $ZZZ$ production processes, and analyse their impacts on both the total cross section and some key distributions. These processes are important for new physics searches at linear colliders. Our results show that KK graviton exchange has the most significant effect on \eerzz among the four processes with relatively small $M_S$, while it has the largest effect on \eerrr with larger $M_S$. By using the neutral triple gauge boson production we could set the discovery limit on the fundamental Plank scale $M_S$ up to around 6-9 TeV for $δ$ = 4 at the 3 TeV CLIC.

hep-ph↗

arXiv2012

On the Clifford theorem for surfaces

We give two generalizations of the Clifford theorem to algebraic surfaces. As an application, we obtain some bounds for the number of moduli of surfaces of general type.

math.AG↗