16223404
Gluon minijet production in nuclear collisions at high energies
We show explicitly that the leading soft gluon p{sub T} distribution, predicted by Kovner, McLerran, and Weigert after solving classical Yang-Mills equations, can be understood in terms of conventional QCD perturbation theory. We also demonstrate that the key logarithm in their result represents the logarithm in DGLAP evolution equations. {copyright} {ital 1999} {ital The American Physical Society}
118936305
Multiple scattering and energy loss in semi-inclusive deeply inelastic eA scattering
We calculate the multiple scattering effect on single hadron production in semi-inclusive lepton-nucleus deeply inelastic scattering. We show that the quantum interference of multiple scattering amplitudes leads to suppression in hadron productions. At the leading power in medium length, the suppression can be approximately expressed in terms of a shift in $z$ of the fragmentation function $D(z)$, and could be therefore interpreted as the collisional energy loss. We compare our calculation with existing experimental data. We also discuss the effect of quark mass on the suppression. Our approach can be extended to other observables in hadronic collisions.
13900650
Nuclear dependence in the Drell-Yan transverse momentum distribution
We calculate the nuclear enhancement in the Drell-Yan transverse momentum distribution in hadron-nucleus collisions. In terms of the multiple scattering picture, we compute the contributions from double scattering. Applying the generalized factorization theorem, we express the nuclear enhancement in terms of twist-4 nuclear parton correlation functions. Using the known information on these twist-4 parton correlation functions, we estimate the nuclear enhancement for Drell-Yan pairs in the large q{sub T} region. We also discuss the source of nuclear suppression in the small q{sub T} region. {copyright} {ital 1998} {ital The American Physical Society}
118914273
Direct photon production in a nuclear environment
42222465
Universality in the nuclear dependence coefficient alpha(q(T))
We derive the nuclear dependence coefficient alpha(q(T)) for Drell-Yan and J/psi production. We show that at small q(T), alpha(q(T)) is given by a universal functional form: alpha(q(T)) = a+bq(2)(T), and the parameters a and b are completely determined by either perturbatively calculable or independently measurable quantities. This universal functional form alpha(q(T)) is insensitive to A, and is consistent with existing data.
14220177
Leading Soft Gluon Production in High Energy Nuclear Collisions
The leading soft gluon pT distribution in heavy ion collisions was ob-tained by Kovner, McLerran, and Weigert after solving classical Yang-Mills equations. I show explicitly this result can be understood in terms of conventional QCD perturbation theory. I also demonstrate that the key logarithm in their result represents the logarithm in DGLAP evolution equations.
15163914
Supernova Neutrinos Detection On Earth
In this paper, we first discuss the detection of supernova neutrino on Earth. Then we propose a possible method to acquire information about θ13 smaller than 1.5 ◦ by detecting the ratio of the event numbers of different flavor supernova neutrinos. Such an sensitivity cannot yet be achieved by the Daya Bay reactor neutrino experiment.
119547297
TEST ON APPLICATION RANGE OF QCD SUM-RULES FROM BARYON SPECTROSCOPY
By considering the nonperturbative QCD effect via quark and gluon condensates, the confinement terms in effective q-q potential can automatically be given. A potential in the form of (Yukawa-type terms) where positive and negative signs appear alternatively in 's is proposed. To testify the validity range of QCD sum rules, the experimental baryon spectrum is fitted and the values of 's as well as their signs are obtained. It is found that in the baryon spectrum calculation, the terms of and are important and higher terms beyond can be neglected. Comparing these values with the result calculated from QCD sum rules, some agreements and disagreements are found.
123500440
Solution of the Schwinger-Dyson Equation Involving the Gluon condensate Kernel*
The form of the quantum chromodynamic Schwinger-Dyson (SD) equation modified by the nonperturbative kernel associated with the gluon condensate is obtained. It is shown that the solution for the renormalization group invariant quark condensate from the SD equation is in agreement with that obtained from the consistent equation for quark condensate when the leading behavior of the dynamical quark mass is concerned. It is also found that the gluon condensate kernel makes the critical coupling constant above which the chiral symmetry breaks smaller and increases the value of the quark condensate.
121699809
A SEMIPHENOMENOLOGICAL DETERMINATION OF QUARK CONDENSATE
A consistent equation for the quark condensate in the chiral limit provides a determination of the renormalization-group-invariant quark condensate. A critical point at which the strong coupling constant is big enough for chiral symmetry breaking to take place is found. They are analyzed at the one- and two-loop levels respectively. An intuitive picture of the condensation above the critical coupling constant is discussed.
17365172
Heavy quark distribution functions in heavy baryons
Using the Bethe-Salpeter (B-S) equations for heavy baryons Lambda_Q, Sigma_Q, Xi_Q and Omega_Q (Q=b or c), which were established in previous work, we calculate the heavy quark distribution functions in these baryons. The numerical results indicate that these distribution functions have an obvious peak at some fraction, alpha_0, of the baryon's light-cone ``plus'' momentum component carried by the heavy quark, and that as m_Q becomes heavier this peak becomes sharper and closer to 1. The dependence of the distribution functions on various input parameters in the B-S model is also discussed. The results are seen to be qualitatively similar to an existing phenomenological model.