118759982
Effects of little Higgs models on single top production at the e- gamma colliders
In the framework of the littlest Higgs($LH$) model and the littlest Higgs model with T-parity($LHT$), We investigate the single top production process $e^{-}\gamma\to \nu_{e}b\bar{t}$, and calculate the corrections of these two models to the cross section of this process. We find that in the reasonable parameter space, the correction terms for the tree-level $Wtb$ couplings coming from the $LHT$ model can generate significantly corrections to the cross section of this process, which might be detected in the future high energy linear $e^{+}e^{-}$ collider($ILC$) experiments. However, the contributions of the new gauge boson $W^{\pm}_{H}$ predicted by the $LH$ model to this process is very small.
14268595
Phase transition of finite size quark droplets with isospin chemical potential in the Nambu–Jona-Lasinio model
Making use of the Nambu\char21{}Jona-Lasinio model and the multiple reflection expansion approximation, we study the phase transition of the finite size droplet with $u$ and $d$ quarks. We find that the dynamical masses of $u$, $d$ quarks are different, and the chiral symmetry can be restored at different critical radii for $u$, $d$ quarks. It provides a clue to understanding the effective nucleon mass splitting in nuclear matter. Meanwhile, it shows that the maximal isospin chemical potential at zero temperature is much smaller than the mass of pion in free space.
43093269
Rare decays of the top quark in the one generation technicolor model.
The decays [ital t][r arrow][ital cV] ([ital V]=[gamma],[ital g],[ital Z]) and [ital t][r arrow][ital cP][sup 0] induced through loop processes are calculated in the Farhi-Susskind one family technicolor (TC) model. We find that these new contributions can enhance the SM branching fractions by as much as 3--4 orders of magnitude, i.e., [ital B]([ital t][r arrow][ital cg])[similar to]10[sup [minus]6], [ital B]([ital t][r arrow][ital cZ])[similar to]10[sup [minus]7], [ital B]([ital t][r arrow][ital c][gamma])[similar to]10[sup [minus]8], and [ital B]([ital t][r arrow][ital cP][sup 0])[similar to]10[sup [minus]9], for the favorable values of the parameters. It might provide a unique window to detect the virtual effects of pseudo Goldstone bosons in TC theory.
122968394
Multiscale technicolor and top quark decay
119099946
The Flavor-changing bottom and anti-strange quark production in the littlest Higgs model with T parity at the ILC
In the littlest Higgs model with T-parity (LHT) the mirror quarks induce the special flavor structures and some new flavor-changing (FC) couplings which could greatly enhance the production rates of the FC processes. We in this paper study some bottom and anti-strange production processes in the LHT model at the International Linear Collider (ILC), i.e., $e^+e^-\to b\bar{s}$ and $\gamma\gamma\to b\bar{s}$. The results show that the production rates of these processes are sizeable for the favorable values of the parameters. Therefore, it is quite possible to test the LHT model or make some constrains on the relevant parameters of the LHT through the detection of these processes at the ILC.
118036569
Detecting Toppion via a Flavor-Changing Single Top QuarkProduction Process*
In the framework of topcolor-assisted technicolor (TC2) theory, we study a flavor changing single top quarkproduction process pp(pp) →Ⅱ0t → tc(tc) at upgraded Tevatron and LHC. The results show that with the flavor changingcoupling of neutral toppion to top and charm quark, toppion provides a large te-channel resonance effect. The signal ofsingle top production could be detected at LHC. Otherwise, the narrow peak in the invariant mass distribution could beclearly detected both at upgraded Tevatron and LHC. Therefore, such single top production process provides a uniqueway to test TC2 model via the detection of tc-channel neutral toppion contribution.
76655214
Hadron production in p+p, p+Pb, and Pb+Pb collisions with the HIJING 2.0 model at energies available at the CERN Large Hadron Collider
The Heavy-Ion Jet Interaction Generator (hijing) Monte Carlo model is updated with the latest parton distributions functions and a new set of the parameters in the two-component minijet model that controls the total p+p cross section and the central pseudorapity density. We study hadron spectra and multiplicity distributions using the hijing2.0 model and compare to recent experimental data from p+p collisions at the Large Hadron Collider (LHC) energies. We also give predictions of hadron production in p+p, p+Pb, and Pb+Pb collisions at the full LHC energy.
119369173
The Distinct Light Curve Shape of the Asteroid (469)
The observation light curves of the main belt asteroid (469) Argentina, obtained on March 9–11 2002 and August 10–11 2004, are presented in this paper. The complex light curve of the (469) suggests that it may be in NPA rotation. Using the Fourier analysis method, some prominent spectrum values are derived individually for two subset data. Among these period values, periods of 13.00 and 8.74 h are regarded as basic components. Other derived period values can be combined linearly with these two basic period values. If the (469) is in a free-force precession mode, the motion mode will be LAM (largest-axis mode) according the ratio of precession and rotation periods. And the minimum of I1/I3 (ratio of the largest and smallest principal momentum of inertial) is 3.05. Assuming an external torque releasing by a satellite forces the (469) to precess, the mass of satellite roughly is the same order as the primary’s on condition that the precession and rotation periods are two basic values. At present, we cannot draw an unambiguous conclusion on (469)’s motion for sparse data, So the further observations are necessary for understanding the (469)’s tumbling motion farther.
119209391
Four jets as a probe of O(100 GeV) physics beyond standard model at hadron colliders
O(100 GeV) physics beyond the standard model (BSM) could be overlooked provided that it is hidden in the untouched Higgs sector or jets. The top quark forward-backward asymmetry measurements and di-jet bump, which is observed in the associated production with charged lepton plus missing energy (supposed arising from W decay), may indicate the existence of a new color-octet axial-vector Z_C with a mass about 145 GeV. Here Z_C only decays into two jets. In this paper we investigated the possibility to discover Z_C pair via analyzing the four jets as the final states, which are heavily polluted by huge QCD background. Our simulation showed that, however, both Tevatron and LHC have the excellent chance to discover Z_C through analyzing the four jets events in the current accumulated data.
119185233
Study on the temperature dependence of BGO light yield
The temperature dependence of BGO coupled with photomultiplier tube R5610A-01 was studied in the range of −30–30°C. The temperature coefficient of the BGO and R5610A as a whole was tested to be −1.82%/°C. And the temperature coefficient of the gain of the R5610A is −0.44%/°C which was tested in the same situation using a blue LED. Thus the temperature coefficient of BGO’s light yield can be evaluated as −1.38%/°C.
18838442
Approach to Parton Equilibration
Abstract Perturbative QCD-based models of parton production and equilibration in ultrarelativistic heavy ion collisions are reviewed with an emphasis on the treatment of quantum interference effects. Uncertainties in the initial parton production and their effects on later parton equilibration are considered. Probes of early parton dynamics are also discussed.