18805981
System size and energy dependence of phi meson production at RHIC
We present a system size and energy dependence of meson production in Cu + Cu and Au + Au collisions at GeV and 200 GeV measured by the STAR experiment at RHIC. We find that the number of participant scaled meson yields in heavy-ion collisions over that of p + p collisions are larger than 1 and increase with collision energy. We compare the results with those of open-strange particles and discuss the physics implication.
122417032
Hypernucleus physics at RHIC
Abstract We report recent progress in hypernucleus studies measured by the STAR collaboration at the Relativistic Heavy Ion Collider. We show a preliminary hypertriton measurement from our current event sample and discuss the next step for this project.
32811554
Model-independent results for SU(3) violation in light-cone distribution functions.
Using chiral symmetry we investigate the leading SU(3) violation in light-cone distribution functions phi(M)(x) of the pion, kaon, and eta. It is shown that terms nonanalytic in the quark masses do not affect the shape, and only appear in the decay constants. Predictive power is retained including the leading analytic m(q) operators. With the symmetry violating corrections we derive useful model-independent relations between phi(pi),phi(eta),phiK+(,K0), and phiK(0)(,K-). Using the soft-collinear effective theory we discuss how factorization generates the subleading chiral coefficients.
118966106
Relaxation from color Compton Scattering of Plasmons in A Collisionless Quark-Gluon Plasma
Non-Abelian kinetic effects are taken into account for the study of the relaxation of collective motion in a quark-gluon plasma(QGP). An explicit Compton scattering is considered to calculate the relaxation time. It is shown that the new non-Abelian relaxation has a physical mechanism from the non-linear dynamics and the meaning of the relaxation is discussed.
119107849
Bose symmetry interference effects of 4 pi final states
We analyze the relative branching ratios of 4 pi final states pi(+)pi(-)pi(+)pi(-), pi(+)pi(-)pi(0)pi(0), and pi(0)pi(0)pi(0)pi(0), from various resonances with J(PC) = 0(++), 0(-+), 2(++). We find that in some cases the interference effects due to Bose symmetry make their ratios obviously different from the naive counting values without these effects. The results allow an accurate estimate of the 4 pi branching ratios of relevant resonances when only one (or two) modes are measured in a given experiment.
56112288
Residue theorem and summing over Kaluza-Klein excitations
Applying the equations of motion together with corresponding boundary conditions of bulk profiles at infrared and ultraviolet branes, we verify some lemmas on the eigenvalues of Kaluza-Klein modes in extension of the standard model with a warped extra dimension and the custodial symmetry SU(3){sub c}xSU(2){sub L}xSU(2){sub R}xU(1){sub X}xP{sub LR}. Using the lemmas and performing properly analytic extensions of bulk profiles, we present the sufficient condition for a convergent series of Kaluza-Klein excitations and sum over the series through the residue theorem. The method can also be applied to sum over the infinite series of Kaluza-Klein excitations in a universal extra dimension. Furthermore, we analyze the possible connection between the propagators in five-dimensional full theory and the product of bulk profiles with corresponding propagators of exciting Kaluza-Klein modes in four-dimensional effective theory, and recover some relations presented in the literature for warped and universal extra dimensions, respectively. As an example, we present the correction from new physics to the branching ratio of B{yields}X{sub s{gamma}} to the order O({mu}{sub EW}{sup 2}/{Lambda}{sub KK}{sup 2}) in extension of the standard model with a warped extra dimension and the custodial symmetry, where {Lambda}{sub KK} denotes the energy scale of low-lying Kaluza-Klein excitations and {mu}{sub EW}more » denotes the electroweak energy scale.« less
49577145
Neutrino deuteron scattering in effective field theory at next-to-next-to-leading order
We study the four channels associated with neutrino-deuteron breakup reactions at next-to-next-to-leading order in effective field theory. We find that the total cross section is indeed converging for neutrino energies up to 20 MeV, and thus our calculations can provide constraints on theoretical uncertainties for the Sudbury Neutrino Observatory. We stress the importance of a direct experimental measurement to high precision in at least one channel, in order to fix an axial two-body counterterm.