Combination of Heavy Quarks with Partons from Quark-Gluon Matter: a Scaling Probe 山东大学物理系 李世渊 • INTRODUCTION : measurement/probe of QGP , via combination processes… success of combination models, more rigorous framework needed for measurement • FORMULAE for PROCESS heavy + light (from QGP) • EXTRACT COMBINATION MATRIX ELEMENTS • NUMERICAL ESTIMATES • CONCLUSION 2019/4/22 RHIC物理和低能强子物理研讨会，威海
• Quantitatively Measure the Distribution of “QGP” Hot dense quark-gluon matter(QGP?) observed at RHIC • Quantitatively Measure the Distribution of “QGP” from now on Heinz adds that it is now important to move away from discovery measurements and to begin characterizing the plasma's behaviour. "We need to start exploring the details of this new kind of matter," says (Ulrich)Heinz. Nature 430, 498 - 499 (29 July 2004); 2019/4/22 RHIC物理和低能强子物理研讨会，威海
Can we measure it via combination processes? RC Hwa & CB Yang , Infer the distribution in the framework of their model the model ☞ nucl-th/0211010, nucl-th/0301004, nucl-th/0302006, nucl-th/0304073, nucl-th/0307112, hep-ph/0312271, nucl-th/0401001, nucl-th/0406072 … Key:Final hadron ‘proportional’ to quark distribution In principle, this can be done by every kinds of QCM How about the combination models? 2019/4/22 RHIC物理和低能强子物理研讨会，威海
In hadronization process… for “QGP” hadronization QCM(1) Date back to 3 decades ago, In hadronization process… V. V. Anisovich et al.,(1973) J. D. Bjorken et al., (1974) K.P. Das & R.C. Hwa(1977) Xie et al. (SDQCM), (1980’s) A Bulk of quarks ( Gluons??), Combine accord. to some rules Now in RHIC, for “QGP” hadronization B. Muller et al., R. Hwa et al., C. Ko et al. (Coalescence), Xie et al., both rate & spectrum Quark Combination Models(QCM) describes hadronization as well as String ,Cluster, Independent Fragmentation, … ©lsy 2019/4/22 RHIC物理和低能强子物理研讨会，威海
They seem ‘succeed’ the later in RHIC e.g.: Combination schemes describe data in various processes as well as the Fragmentation scheme, which describes inclusive production. PQCD FACTORIZATION They seem ‘succeed’ the later in RHIC e.g.: Perfect scaling for all measured hadrons, some deviation for pions (from decays) The success of combination model also indicates local equilibium 2019/4/22 RHIC物理和低能强子物理研讨会，威海
2019/4/22 RHIC物理和低能强子物理研讨会，威海
So we want to FIX as many as possible. The success of QCMS for RHIC is “annoyed” by the uncertainties in various models. Quark distribution Combination rule both by hand uncertainties : call for further investigation So we want to FIX as many as possible. 2019/4/22 RHIC物理和低能强子物理研讨会，威海
QCM(2) Now comes Heavy Quark combination Asymmetry of D mesons in forward direction Theo.: Braaten et al (2002), Phys.Rev.Lett.89:122002,2002 The parton spectra calculated in PQCD, param.: only a probability（more uniform, ☞Ma& Si) Exp.: E791: 500GeV π-beam on nuclear target 2019/4/22 RHIC物理和低能强子物理研讨会，威海
At the same time,☞ d+Au experiments indicate… spectra are harder than PYTHIA extrapolation from low energies! (hard fragmentation function, charm quark recombination …?) 2019/4/22 RHIC物理和低能强子物理研讨会，威海
•though the light parton spectrum in QGP unknown Now how about QCM in AA when heavy quarks present? Further step more than naïve models •though the light parton spectrum in QGP unknown heavy quark spectrum calculable So We can know more! ☞ key: How to describe the combination with one parton from “QGP” in the framework of PQCD factorization Following Qiu and Vitev, start from Factorization hard proc.+universal param. 2019/4/22 RHIC物理和低能强子物理研讨会，威海
In principle: ☞ Hard Inter. ☞ Charm Meson ME ☞ More than the naïve QCM Parton Distr. In QGP 2019/4/22 RHIC物理和低能强子物理研讨会，威海
1 = = 2 2019/4/22 RHIC物理和低能强子物理研讨会，威海
Higher orders factorization: Infrared cancel between real and virtual everywhere; Collinear for initial parton lead to DGLAP; AND Normal DGLAP Vacuum radiation+medium radiation No Collinear singularity for heavy! VR+MR; But collinear absorbed into Evolution 2019/4/22 RHIC物理和低能强子物理研讨会，威海
To extract the ME in other processes, e. g. , light q frag To extract the ME in other processes, e.g., light q frag. into charm meson in e+e- 2019/4/22 RHIC物理和低能强子物理研讨会，威海
CM ME, AA UNIVERSAL 2019/4/22 RHIC物理和低能强子物理研讨会，威海
Same ME value as Braaten et al., 2019/4/22 RHIC物理和低能强子物理研讨会，威海
Indication of recent data ?! Differences between data and theo. for in e+e- LEP/SLD world average 2001: vs. Theo.:2.007% This diff. leaves space for the recombination process As an first approxi. we can use the value of Braaten More precise measurement: Giga Z! DJ Miller et al., 2019/4/22 RHIC物理和低能强子物理研讨会，威海 *The MC of the shape of these events indicates that part of which could have been included when measuring
Simple numerical estimation Short for Simple numerical estimation In central region, harder than quark Much diff. For various distr. Suit for being probe 2019/4/22 RHIC物理和低能强子物理研讨会，威海
CONCLUSION Quark-gluon matter to be measured @RHIC &LHC QCM successful in RHIC, can be used for measure Uncertainties both quark distri. and comb. rules In the PQCD factorization framework, for universal parameters+hard process We have one parameter as “PDF of QGP” & the Simple scaling relation • Extract comb. ME from, e.g., light to HM in e+e- Comp. wrt data(RHIC,LHC…), we get knowledge on “PDF ”of QGP as well as those of proton, pion photon… • This is also a good framework for light quark jet combination Acknowledgements Part of the work done with 金毅博士 Topic of D mesons suggested by and discussed many times with 王新年教授 Many helpful discussions with 谢去病教授 司宗国教授 邵凤兰博士… Supported in pat by NSFC, Grant No. 10205009 2019/4/22 RHIC物理和低能强子物理研讨会，威海
2019/4/22 RHIC物理和低能强子物理研讨会，威海
☞ Hard Inter. ☞ Charm Meson ME ☞ Parton Distr. In QGP 2019/4/22 RHIC物理和低能强子物理研讨会，威海
☞ Hard Inter. ☞ Charm Meson ME ☞ Parton Distr. In QGP 2019/4/22 RHIC物理和低能强子物理研讨会，威海
2019/4/22 RHIC物理和低能强子物理研讨会，威海
☞ Hard Inter. ☞ Charm Meson ME ☞ Parton Distr. In QGP 2019/4/22 RHIC物理和低能强子物理研讨会，威海
2019/4/22 RHIC物理和低能强子物理研讨会，威海