1,875 research outputs found
Strange Tribaryons as Nona-quark States
Strange tribaryons as nona-quark (9 quark) states is studied to describe the
S=-1 resonance S^0(3115) recently discovered in the reaction K- + ^4 He -> S^0
+ p. We have identified S^0(3115) as a member of the flavor 27-plet, in
particular, (F_{flavor},I_{isospin},J_{spin})=(27,1,1/2) or (27,1,3/2). The
color-magnetic interaction between quarks favors small multiplets in flavor and
spin, which leads to a natural explanation that I=1 is the lowest state among
the S=-1 tribaryons with J=1/2. Classification of the S^+ -state recently
reported as well as possible locations of other light strange tribaryons such
as (10*,0,3/2) with S=-1, (8,1/2,1/2) with S=-2 and (1,0,3/2) with S=-3 are
also discussed.Comment: 10 pages, 3 figure
Equation of state in 2+1 flavor QCD with improved Wilson quarks by the fixed scale approach
We study the equation of state in 2+1 flavor QCD with nonperturbatively
improved Wilson quarks coupled with the RG-improved Iwasaki glue. We apply the
-integration method to nonperturbatively calculate the equation of state by
the fixed-scale approach. With the fixed-scale approach, we can purely vary the
temperature on a line of constant physics without changing the system size and
renormalization constants. Unlike the conventional fixed- approach, it is
easy to keep scaling violations small at low temperature in the fixed scale
approach. We study 2+1 flavor QCD at light quark mass corresponding to
, while the strange quark mass is chosen around the
physical point. Although the light quark masses are heavier than the physical
values yet, our equation of state is roughly consistent with recent results
with highly improved staggered quarks at large .Comment: 14 pages, 12 figures, v2: Table I and Figure 3 are corrected,
reference updated. Main discussions and conclusions are unchanged, v3:
version to appear in PRD, v4: reference adde
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