Theory on Hadrons in Nuclear Medium

After decades-long attempts to measure the mass shift and understand the origin of hadron mass, it became clear that one has to analyze hadrons with small vacuum width. Also, to identify the effect of chiral symmetry breaking, one has to start by looking at chiral partners. In this talk, I will review why such consideration inevitably led us to consider $K^*$ and $K_1$ in nuclear matter [T. Song, T. Hatsuda, S H Lee, PLB792 (2019) 160-169]. With the kaon beam at JPARC, one could observe the mass shift of both particles in a nuclear target experiment. Once the masses and mass difference of $K^*$ and $K_1$ mesons are measured, we will be closer to understanding the origin of the hadron masses and the effects of chiral symmetry breaking in them.Comment: 8 pages, Plenary talk at QNP-201

The mass of charmonium in nuclear matter

The masses of charmonium states immersed in nuclear matter are calculated in LO QCD and in QCD sum rules. While the mass shift for $J/\psi$ are found to be less than -10 MeV, those for the $\chi_{0,1,2}$ and $\psi(3686)$ and $\psi(3770)$ are found to be more than -40 MeV. We investigate the feasibility of observing such mass shifts in the future accelerator project at GSI.Comment: 5 pages, proceeding for Hadron 200

Top quark mass and property measurements at Tevatron

The top quark, discovered in 1995 at the Fermilab Tevatron collider from CDF and D0 experiments, remains by far the most interesting particle to test standard model because of its large mass and unique properties. Having data collected about 10 fb$^{-1}$ of integrated luminosity of $p\bar{p}$ collision, both experiments have been studied the top quark in all the possible directions. In this article, we present the recent measurements of the top quark properties from Tevatron including the mass, width, spin correlation, and $W$ boson helicity using $t\bar{t}$ signature.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 4 pages, 6 figur

Quantum state engineering by a coherent superposition of photon subtraction and addition

We study a coherent superposition of field annihilation and creation operator acting on continuous variable systems and propose its application for quantum state engineering. Specifically, it is investigated how the superposed operation transforms a classical state to a nonclassical one, together with emerging nonclassical effects. We also propose an experimental scheme to implement this elementary coherent operation and discuss its usefulness to produce an arbitrary superposition of number states involving up to two photons.Comment: published version, 7 pages, 8 figure

Top-Quark Mass Measurement in the Dilepton Channel Using {\it in situ} Jet Energy Scale Calibration

We employ a top-quark mass measurement technique in the dilepton channel with {\it in situ} jet energy scale calibration. Three variables having different jet energy scale dependences are used simultaneously to extract not only the top-quark mass but also the energy scale of the jet from a single likelihood fit. Monte Carlo studies with events corresponding to an integrated luminosity of 5 fb$^{-1}$ proton-proton collisions at the Large Hadron Collider $\sqrt{s} = 7$ TeV are performed. Our analysis suggests that the overall jet energy scale uncertainty can be significantly reduced and the top-quark mass can be determined with a precision of less than 1 GeV/c$^2$, including jet energy scale uncertainty, at the Large Hadron Collider.Comment: Submitted to Phys. Rev.

Quarkonium-Hadron Interactions in Perturbative QCD

The next to leading order (NLO) quarkonium-hadron cross section is calculated in perturbative QCD. The corresponding leading order (LO) result was performed by Peskin more than 20 years ago using the operator product expansion (OPE). In this work, the calculation is performed using the Bethe-Salpeter amplitude and the factorization formula. The soft divergence appearing in the intermediate stages of the calculations are shown to vanish after adding all possible crossed terms, while the collinear divergences are eliminated by mass factorization. Applying the result to the Upsilon system, one finds that there are large higher order correction near the threshold. The relevance of the present result to the charmonium case is also discussed.Comment: Yonsei University. to be published in PR