Bose-Einstein Correlations for Mixed Neutral Mesons

Correlations are shown to arise in nonidentical mixed-particle pairs like $K^o \bar K^o$ when observed in identical decay modes like $K_S K_S$ in multiparticle final states containing many partial waves. No enhancement is found in any single partial wave and all partial wave analyses of the s-wave threshold resonance $a_o$ and $f_o$ should give the same results for all decay modes. In CP violation experiments where $B^o - \bar B^o$ pairs are inclusively produced and correlated decays into $\psi K_S$ and leptonic modes are observed, the CP-violating lepton asymmetry is enhanced by a factor of two in the kinematic region where Bose enhancement occurs.Comment: 11 page

Measuring Double Parton Distributions in Nucleons at Proton-Nucleus Colliders

We predict a strong enhancement of multijet production in proton-nucleus collisions at collider energies, as compared to a naive expectation of a cross section $\propto A$. The study of the process would allow to measure, for the first time, the double parton distribution functions in a nucleon in a model independent way and hence to study both the longitudinal and the transverse correlations of partons.Comment: 12 pages, 2 figure

Transverse Momentum Spectra of Pions in Particle and Nuclear Collisions and Some Ratio-Behaviours: Towards A Combinational Approach

The nature of transverse momentum dependence of the inclusive cross-sections for secondary pions produced in high energy hadronic($PP$), hadronuclear($PA$) and nuclear($AA$) collisions has here been exhaustively investigated for a varied range of interactions in a unified way with the help of a master formula. This formula evolved from a new combination of the basic Hagedorn's model for particle(pion) production in PP scattering at ISR range of energies, a phenomenological approach proposed by Peitzmann for converting the results of $NN(PP)$ reactions to those for either $PA$ or $AA$ collisions, and a specific form of parametrization for mass number-dependence of the nuclear cross sections. This grand combination of models(GCM) is then applied to analyse the assorted extensive data on various high energy collisions. The nature of qualitative agreement between measurements and calculations on both the inclusive cross-sections for production of pions, and some ratios of them as well, is quite satisfactory. The modest successes that we achieve here in dealing with the massive data-sets are somewhat encouraging in view of the diversity of the reactions and the very wide range of interaction energies.Comment: 19 pages, 19 figure

Double parton scatterings in high energy hadronic collisions

CDF has recently measured a large number of double parton scatterings. The observed value of $\sigma_{eff}$, the non perturbative parameter which characterizes the process, is considerably smaller as compared with the naive expectation. The small value of $\sigma_{eff}$ is likely to be an indication of the importance of the two-body parton correlations in the many-body parton distributions of the proton.Comment: 8 pages, latex file, no figures, contributions to the proceedings of the ISMD9

K∗(892)K^{*}(892) Production in Au+Au and pp Collisions at sNN\sqrt{s_{NN}} = 200GeV at STAR

Mid-rapidity $K^{*0}(892)\to K\pi$ and $K^{*\pm}(892)\to K_S^0\pi^{\pm}$ are measured in Au+Au and pp collisions at $\sqrt{s_{NN}}$=200GeV using the STAR detector at RHIC. The $K^{*0}(892)$ mass is systematically shifted at small transverse momentum for both Au+Au and pp collisions. The $K^{*0}(892)$ transverse mass spectra are measured in Au+Au collisions at different centralities and in pp collisions. The $K^{*0}(892)$ mean transverse momentum as a function of the collision centrality is compared to those of identified $\pi^{-}$, $K^{-}$ and $\bar{p}$. The $K^{*}/K$ and $\phi/K^{*}$ ratios are compared to measurements in A+A, $pp$, $\bar{p}p$, $e^{+}e^{-}$ collisions at various colliding energies. The physics implications of these measurements are also discussed.Comment: 6 pages, 4 figures, proceedings of Strange Quarks in Matter (SQM2003), Atlantic Beach, USA, to be published in J. Phys.

Examination of direct-photon and pion production in proton-nucleon collisions

We present a study of inclusive direct-photon and pion production in hadronic interactions, focusing on a comparison of the ratio of gamma/pi0 yields with expectations from next-to-leading order perturbative QCD (NLO pQCD). We also examine the impact of a phenomenological model involving k_T smearing (which approximates effects of additional soft-gluon emission) on absolute predictions for photon and pion production and their ratio.Comment: 20 pages, 12 figures. Minor changes in wording and in figure

Relevance of baseline hard proton-proton spectra for high-energy nucleus-nucleus physics

We discuss three different cases of hard inclusive spectra in proton-proton collisions: high $p_T$ single hadron production at $\sqrt{s}\approx$ 20 GeV and at $\sqrt{s}$ = 62.4 GeV, and direct photon production at $\sqrt{s}$ = 200 GeV; with regard to their relevance for the search of Quark Gluon Plasma signals in A+A collisions at SPS and RHIC energies.Comment: Proceeds. Hot Quarks 2004 Int. Workshop on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions. 26 pages. 26 figs. [minor corrs., refs. added

Incorporating expression data in metabolic modeling: a case study of lactate dehydrogenase

Integrating biological information from different sources to understand cellular processes is an important problem in systems biology. We use data from mRNA expression arrays and chemical kinetics to formulate a metabolic model relevant to K562 erythroleukemia cells. MAP kinase pathway activation alters the expression of metabolic enzymes in K562 cells. Our array data show changes in expression of lactate dehydrogenase (LDH) isoforms after treatment with phorbol 12-myristate 13-acetate (PMA), which activates MAP kinase signaling. We model the change in lactate production which occurs when the MAP kinase pathway is activated, using a non-equilibrium, chemical-kinetic model of homolactic fermentation. In particular, we examine the role of LDH isoforms, which catalyze the conversion of pyruvate to lactate. Changes in the isoform ratio are not the primary determinant of the production of lactate. Rather, the total concentration of LDH controls the lactate concentration.Comment: In press, Journal of Theoretical Biology. 27 pages, 9 figure

Inclusive Dielectron Cross Sections in p+p and p+d Interactions at Beam Energies from 1.04 to 4.88 GeV

Measurements of dielectron production in p+p and p+d collisions with beam kinetic energies from 1.04 to 4.88 GeV are presented. The differential cross section is presented as a function of invariant pair mass, transverse momentum, and rapidity. The shapes of the mass spectra and their evolution with beam energy provide information about the relative importance of the various dielectron production mechanisms in this energy regime. The p+d to p+p ratio of the dielectron yield is also presented as a function of invariant pair mass, transverse momentum, and rapidity. The shapes of the transverse momentum and rapidity spectra from the p+d and p+p systems are found to be similar to one another for each of the beam energies studied. The beam energy dependence of the integrated cross sections is also presented.Comment: 15 pages and 16 figure