3,352 research outputs found
Top-charm associated production at hadron colliders in the standard model with large extra dimensions
The precise calculations are carried out on the flavor changing neutral
current couplings in the process at the
large hadron collider(LHC) and very large hadron collider(VLHC) in both
frameworks of the minimal standard model(MSM) and its extension with extra
dimensions. We find that the effects from the large extra dimensions can
enhance the total cross section up to about several hundred times as that in
the MSM, quantitatively.Comment: 5 pages, 8 figure
production in the Randall-Sundrum model at LHC and CLIC
We study the productions at both the CERN Large Hadron
Collider (LHC) and the Compact Linear Collider (CLIC) in the framework of the
Randall-Sundrum (RS) model. The impacts of the virtual RS Kaluza-Klein (KK)
graviton on these processes are studied and compared with the standard model
(SM) background. We present the integrated and differential cross sections in
both the RS model and the SM. The results show that the relative RS
discrepancies at the CLIC differ from those at the LHC, particularly in the
transverse momentum and rapidity distributions. We also find that the RS
signature performance, as a result of the resonance character of the RS
KK-graviton spectrum, is distinctively unlike that in the large extra
dimensions model. We conclude that the CLIC with unprecedented precision and
high center-of-mass energy has a potential advantage over the LHC in exploring
the effects of the RS KK graviton on the production
processes.Comment: 22 pages, 18 figure
Associated production of graviton with pair via photon-photon collisions at a linear collider
We investigate the process \rreeG at the future International Linear
Collider(ILC), where G_n is the Kaluza-Klein graviton in the Large Extra
Dimension Model. When the fundamental energy scale is of a few , the
cross section of this process can reach several hundred fb at a photon-photon
collider with , and the cross section in J=2
polarized photon collision mode is much larger than that in J=0 polarized
photon collision mode. We present strategies to distinguish the graviton signal
from numerous SM backgrounds, and find that the graviton signal with extra
dimensions can be detected when
and c.m.s. energy in unpolarized
photon collision mode, while the detecting upper limit can be increased to
2.79(1.44) in (, ) polarized
photon collision mode(with photon polarization efficiency ).Comment: Accepted by Phys. Rev.
Double Higgs boson production and decay in Randall-Sundrum model at hadron colliders
We investigate the double Higgs production and decay at the
LHC and HE-LHC in both the standard model and Randall-Sundrum
(RS) model. In our calculation we consider reasonably only the contribution of
the lightest two Kaluza-Klein (KK) gravitons. We present the integrated cross
sections and some kinematic distributions in both models. Our results show that
the RS effect in the vicinities of , (the masses of
the lightest two KK gravitons) or in the central Higgs rapidity region is quite
significant, and can be extracted from the heavy SM background by imposing
proper kinematic cuts on final particles. We also study the dependence of the
cross section on the RS model parameters, the first KK graviton mass and
the effective coupling , and find that the RS effect is reduced obviously
with the increment of or decrement of .Comment: 26 pages, 11 figure
Topological phases of spinless -orbital fermions in zigzag optical lattices
Motivated by the experiment [St-Jean {\it et al}., Nature Photon. {\bf 11},
651 (2017)] on topological phases with collective photon modes in a zigzag
chain of polariton micropillars, we study spinless -orbital fermions with
local interorbital hoppings and repulsive interactions between and
bands in zigzag optical lattices. We show that spinless -band fermions in
zigzag optical lattices can mimic the interacting Su-Schrieffer-Heeger model
and the effective transverse field Ising model in the presence of local
hoppings. We analytically and numerically discuss the ground-state phases and
quantum phase transitions of the model. This work provides a simple scheme to
simulate topological phases and the quench dynamics of many-body systems in
optical lattices.Comment: 6 pages, 5 figure
NLO QCD and electroweak corrections to production with -boson leptonic decays at LHC
In this paper we present the full NLO QCD + NLO EW corrections to the
-boson pair production in association with a hard jet at the LHC. The
subsequent -boson leptonic decays are included by adopting both the naive
NWA and MadSpin methods for comparison. Since the production is
an important background for single Higgs boson production and new physics
search at hadron colliders, the theoretical predictions with high accuracy for
the hadronic production of are necessary. We present the
numerical results of the integrated cross section and various kinematic
distributions of final particles, and conclude that it is necessary to take
into account the spin correlation and finite width effects from the -boson
leptonic decays. We also find that the NLO EW correction is quantitatively
nonnegligible in matching the experimental accuracy at the LHC, particularly is
significant in high transverse momentum region.Comment: 22 pages, 9 figure
Searching for lepton-flavor-violating decay at super charm-tau factory
We investigate the possibility of searching the lepton-flavor-violating (LFV)
rare decay at the Super Charm-Tau Factory (CTF). By
comparing the kinematic distributions of the LFV signal and the standard model
(SM) background, we develop an optimized event selection criteria which can
significantly reduce the background events. It is concluded that new
upper limit of about on
can be obtained at the CTF, which is beyond the capability of Super-B factory
in searching lepton rare decay. Within the framework of the scalar
leptoquark model, a joint constraint on and can
be derived from the upper bound on . With
data expected at the CTF, we get and at confidence level
(C.L.).Comment: 15 pages, 9 figure
Triple -boson production in large extra dimensions model at ILC
We investigate the effects induced by the interactions of the Kaluza-Klein
(KK) graviton with the standard model (SM) particles on the triple -boson
production process at the ILC in the framework of the large extra dimension
(LED) model. We present the dependence of the integrated cross sections on the
electron-positron colliding energy , and various kinematic
distributions of final bosons and their subsequential decay products in
both the SM and the LED model. We also provide the relationship between the
integrated cross section and the fundamental scale by taking the number
of the extra dimensions () as 3, 4, 5, and 6, respectively. The numerical
results show that the LED effect can induce a observable relative discrepancy
for the integrated cross section (), which can reach the value of
when and the colliding energy . We find the relative discrepancy of LED effect can even reach few
dozen percent in the high transverse momentum area or the central rapidity
region of the final -bosons and muons.Comment: 14 pages, 7 figure
production in large extra dimensions model at LHC and ILC
We investigate the effect induced by the Kaluza-Klein (KK) graviton in the
production in the framework of the large extra dimensions
(LED) model at both the CERN Large Hadron Collider (LHC) and the International
Linear Collider (ILC). The integrated cross sections and various kinematic
distributions in the LED model are presented and compared with those in the
standard model. The results show that the contributions from KK-graviton
exchange remarkably affect the observables of the triple gauge boson
() production processes at both the ILC and the LHC,
particularly either in the high transverse momentum region or in the central
rapidity region. We also find that the relative LED discrepancy for the
production at the LHC is generally larger than that at the ILC
due to the additional LED contribution via fusion subprocess and the
KK-graviton exchanging resonant effect induced by the continuous large
colliding energy in collision. We conclude that the and
productions at the LHC could have the distinct advantage over at
the ILC from the aspect of effectively exploring the LED signal in measuring
production.Comment: 23 pages, 19 figure
P-wave excited meson photoproduction at the LHeC
As an important sequential work of the S-wave ()
meson production at the large hadron electron collider (LHeC), we investigate
the production of the P-wave excited states ( and
with ) via photoproduction mechanism within the framework of
nonrelativistic QCD at the LHeC. Generally, the process is considered as the main production
mechanism at an electron-proton collider due to the large luminosity of the
gluon. However, according to our experience on the S-wave meson
production at the LHeC, the extrinsic production mechanism, i.e., and , could also provide dominating contributions at low
region. A careful treatment between these channels is performed and the results
on total and differential cross sections, together with main uncertainties are
discussed. Taking the quark masses GeV and
GeV into account and summing up all the production channels, we expect to
accumulate ,
,
and
events at the
LHeC in one operation year with luminosity cms. With such sizable events, it is worth studying the
properties of excited P-wave states at the LHeC
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