Seminars

ハドロン物理セミナーでは、気鋭の研究者に最近の研究のお話をしていただきます。

We invite spirited researchers as speakers of the Hadron Physics Seminar.

*  以下の時間は、UTC + 9である日本標準時（JST）です。

*  The schedule below is in terms of Japan Standard Time (JST), namely UTC +9.

Mon, May 26th

TBA

Daisuke Fujii (JAEA)
Room 907 (16:00-18:00)

Abstract:

Mon, Apr 21st

Gluon saturation in stopping and particle production

Georg Wolschin (Heidelberg Univ.)
Room 907 (16:00-17:00)

Abstract: In relativistic heavy-ion collisions, stopping in the initial collision stages is accompanied by a local thermalization of gluons towards the Bose–Einstein distribution, and of valence quarks towards the Fermi–Dirac limit. Whereas the thermalization can be accounted for by an analytically solvable nonlinear diffusion model, we describe the time-dependent slowing down (“stopping”) of the fragments based on a QCD-inspired model for the interaction of valence quarks and soft gluons in the respective other nucleus. For stopping data in the peak region at LHC that could determine the gluon saturation scale, a forward-spectrometer would be needed to distinguish protons from pions and kaons. Charged-hadron production in symmetric (Pb–Pb) and asymmetric (p–Pb) collisions also depends on the gluon saturation scale Qs, and we investigate its centrality dependence in p–Pb at √sNN = 5.02 and 8.16 TeV.

Mon, Apr 7th

Chiral model description of exotic diquark and its application to singly-heavy baryon spectrum

Suenaga Daiki (Nagoya Univ.)
Room 907 (16:00-17:00)

Abstract: Among singly-heavy baryons (SHBs) made of a heavy quark and two light quarks, it is known that the mass and decay width of the Roper-like Λc(2765) whose spin and parity are expected to be J^P=1/2^+ cannot be explained easily by a simple quark model. SHB properties are mostly determined by light diquarks inside by virtue of the heavy-quark effective theory. In this talk, in order to to describe the Roper-like and ground-state \Lambda_c baryons simultaneously, I introduce a new type of diquarks, qq\bar{q}q, in addition to the conventional ones, qq, based on a chiral model. The Roper-like and ground-state \Lambda_c baryons seem to be dominated by Qqq\bar{q}q and Qqq, respectively. The masses of negative-parity baryons are also predicted. Besides, I present a mass formula and the extended Goldberger-Treiman relation among the SHBs.