223459
The single t-quark productions via the flavor-changing processes in the topcolor-assisted technicolor model at the hadron colliders
In the framework of topcolor-assisted technicolor(TC2) model, there exist tree-level flavor-changing (FC) couplings which can result in the loop-level FC coupling tcg. Such tcg coupling can contribute significant clues at the forthcoming Large Hadron Collider (LHC) experiments. In this paper, based on the TC2 model, we study some single tquark production processes involving tcg coupling at the Tevatron and LHC: pp(pp̄) → tq̄(q = u, d, s), tg. We calculate the cross sections of these processes. The results show that the cross sections at the Tevatron are too small to observe the signal, but at the LHC it can reach a few pb. With the high luminosity, the LHC has considerable capability to find the single t-quark signal produced via some FC processes involving coupling tcg. On the other hand, these processes can also provide some valuable information of the coupling tcg with detailed study of the processes and furthermore provide the reliable evidence to test the TC2 model. PACS number(s): 12.60Nz, 14.80.Mz, 12.15.LK, 14.65.Ha Email Address: wangxuelei@sina.com Email Address: xiaozhenjun@njnu.edu.cn
122968394
Multiscale technicolor and top quark decay
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.
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.
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.
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.
119238692
Effect of longitudinal fluctuation in event-by-event (3+1)D hydrodynamics
Abstract Hadron spectra and elliptic flow in relativistic heavy-ion collisions are studied in event-by-event (3+1)D ideal hydrodynamic simulations with fluctuating initial conditions given by the AMPT Monte Carlo model. Both the coherent soft gluon production from wounded nucleons and incoherent mini-jet production in semi-hard parton scatterings are considered. These partons take part in parton cascade and are assumed to be locally thermalized. They provide the fluctuating initial conditions for hydrodynamic simulations with a Gaussian smearing. Effects of both transverse and longitudinal fluctuations are studied. The initial fluctuations along rapidity direction lead to expanding hot spots in longitudinal direction, which will reduce elliptic flow and the yield of particles at high transverse momentum. The intrinsic correlation introduced in the fluctuating initial conditions is also found to influence the di-hadron correlation of the final hadrons.
121590045
Two particle correlations in jets and triggered distributions in hot and cold matter
The modification of the correlation between high p T particles produced in association with trigger particles from jets emanating from a heavy-ion collision is shown to be a valuable probe of the matter produced in such collisions. While the minimal modification on the same side as the trigger is consistent with the picture and parameters of partonic energy loss, the possible observation of Cherenkov like correlations on the away side leads to the possibility of the existence of composite structures in the excited matter.
14560383
Charmonium production from hot hadronic matter
Abstract Charmonium production from D D annihilation in the hadron gas formed in ultra-relativistic heavy-ion collisions is studied. With initial conditions taken from the HIJING parton model, we have estimated the number of J / ψ produced from an expanding hadron gas, using the J / ψ absorption and production cross sections obtained from either an effective Lagrangian or the quark-exchange model. We find that J / ψ production is negligible in heavy-ion collisions at the Relativistic Heavy Ion Collider (RHIC) but may be important at the Large Hadron Collider (LHC), where more charm mesons are produced. Similar results are obtained for ψ ′ production from the hadron gas at RHIC and LHC.
118479131
Venus transit, aureole and solar diameter
The possibility to measure the solar diameter using the transits of Mercury has been exploited to investigate the past three centuries of its evolution and to calibrate these measurements made with satellites. This measurement basically consists to compare the ephemerides of the internal contact timings with the observed timings. The transits of Venus of 2004 and 2012 gave the possibility to apply this method, involving a planet with atmosphere, with the refraction of solar light through it creating a luminous arc all around the disk of the planet. The observations of the 2012 transit made to measure the solar diameter participate to the project Venus Twilight Experiment to study the aureole appearing around it near the ingress/egress phases.
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.