14,548 research outputs found

### Study of the slepton non-universality at the CERN Large Hadron Collider

In supersymmetric theory, the sfermion-fermion-gaugino interactions conserve
the chirality of (s)fermions. The effect appears as the charge asymmetry in
$m(jl)$ distributions at the CERN Large Hadron Collider where jets and leptons
arise from the cascade decay $\tilde{q} \to q \tilde{\chi}^0_2 \to
ql\tilde{l}$. Furthermore, the decay branching ratios and the charge
asymmetries in $m(jl)$ distributions are flavor non-universal due to the
$\tilde{l}_L$ and $\tilde{l}_R$ mixing. When $\tan\beta$ is large, the
non-universality between $e$ and $\mu$ becomes $O(10)%$ level. We perform a
Monte Carlo simulation for some minimal supergravity benchmark points to
demonstrate the detectability.Comment: 19 pages, 6 figures, revte

### NMR relaxation of quantum spin chains in magnetic fields

We investigate NMR relaxation rates 1/T_1 of quantum spin chains in magnetic
fields. Universal properties for the divergence behavior of 1/T_1 are obtained
in the Tomonaga-Luttinger-liquid state. The results are discussed in comparison
with experimental results.Comment: 5 pages, 3 figure

### Environmental dependence of 8um luminosity functions of galaxies at z~0.8: Comparison between RXJ1716.4+6708 and the AKARI NEP deep field

We aim to reveal environmental dependence of infrared luminosity functions
(IR LFs) of galaxies at z~0.8 using the AKARI satellite. We construct restframe
8um IR LFs in the cluster region RXJ1716.4+6708 at z=0.81, and compare them
with a blank field using the AKARI North Ecliptic Pole deep field data at the
same redshift. AKARI's wide field of view (10'x10') is suitable to investigate
wide range of galaxy environments. AKARI's 15um filter is advantageous here
since it directly probes restframe 8um at z~0.8, without relying on a large
extrapolation based on a SED fit, which was the largest uncertainty in previous
work. We have found that cluster IR LFs at restframe 8um have a factor of 2.4
smaller L^* and a steeper faint-end slope than that of the field. Confirming
this trend, we also found that faint-end slopes of the cluster LFs becomes
flatter and flatter with decreasing local galaxy density. These changes in LFs
cannot be explained by a simple infall of field galaxy population into a
cluster. Physics that can preferentially suppress IR luminous galaxies in high
density regions is required to explain the observed results.Comment: Accepted for publication in A&A AKARI special issu

### Muon spin relaxation and rotation study on the solid solution of the two spin-gap systems (CH3)2CHNH3-CuCl3 and (CH3)2CHNH3-CuBr3

Muon-spin-rotation and relaxation studies have been performed on
(CH$_3$)$_2$CHNH$_3$Cu(Cl$_x$Br$_{1-x}$)$_3$ with $x$=0.85 and 0.95, which are
solid solutions of the two isomorphic spin-gap systems
(CH$_3$)$_2$CHNH$_3$CuCl$_3$ and (CH$_3$)$_2$CHNH$_3$CuBr$_3$ with different
spin gaps. The sample with $x$=0.85 showed a clear muon spin rotation under
zero-field below $T_{\rm N}$=11.65K, indicating the existence of a long-range
antiferromagnetic order. A critical exponent of the hyperfine field was
obtained to be $\beta$=0.33, which agrees with 3D-Ising model. In the other
sample with $x$=0.95, an anomalous enhancement of the muon spin relaxation was
observed at very low temperatures indicating a critical slowing down due to a
magnetic instability of the ground state

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