1,132 research outputs found
Comparison of the EPIC Physical Activity Questionnaire with combined heart rate and movement sensing in a nationally representative sample of older British adults
Peer reviewedPublisher PD
Aspects of Axion Phenomenology in a slice of AdS_5
Motivated by multi-throat considerations, we study the phenomenological
implications of a bulk axion in a slice of AdS_5 with a large extra dimension:
k~0.01 eV, kR > 1. In particular, we compare axion physics with a warped
geometry to axions in flat compactifications. As in flat compactification
scenarios, we find that the mass of the axion can become independent from the
underlying Peccei-Quinn scale. Surprisingly, we find that in warped extra
dimensions the axion's invisibility, cosmological viability, and basic
phenomenology remain essentially unaltered in comparison to axions in flat
compactifications.Comment: 25 pages, 9 figure
Cosmological constraints on neutrino plus axion hot dark matter: Update after WMAP-5
We update our previous constraints on two-component hot dark matter (axions
and neutrinos), including the recent WMAP 5-year data release. Marginalising
over sum m_nu provides m_a < 1.02 eV (95% C.L.) for the axion mass. In the
absence of axions we find sum m_nu < 0.63 eV (95% C.L.).Comment: 4 pages, 1 figure, uses iopart.cls; v2 matches published versio
Simple predictions from ALCOR_c for rehadronisation of charmed quark matter
We study the production of charmed hadrons with the help of ALCOR_c, the
algebraic coalescence model for rehadronisation of charmed quark matter.
Mesonic ratios are introduced as factors connecting various antibaryon to
baryon ratios. The resulting simple relations could serve as tests of quark
matter formation and coalescence type rehadronization in heavy ion collisions.Comment: 7 pages in Latex, 1 PS figur
CP violation in the secluded U(1)'-extended MSSM
We study the Higgs sector of the secluded -extended MSSM (sMSSM)
focusing on CP violation. Using the one-loop effective potential that includes
contributions from quarks and squarks in the third generation, we search for
the allowed region under theoretical and experimental constraints. It is found
that the possible region for the electroweak vacuum to exist is quite limited,
depending on the parameters in the model. The masses and couplings of the Higgs
bosons are calculated with/without CP violation. Even at the tree level, CP
violation is possible by complex soft SUSY breaking masses. Similar to the CPX
scenario in the MSSM, the scalar-pseudoscalar mixing enables the lightest Higgs
boson mass to become smaller than the boson mass while the coupling with
the boson is sufficiently suppressed to avoid the LEP experimental
constraints. However, unlike the CPX scenario, large and are not
required for the realization of large CP violation. The typical spectrum of the
SUSY particles is thus different. We also investigate the possible upper bound
of the lightest Higgs boson in the case of spontaneous CP violation. The
maximal value of it can reach above 100 GeV with maximal CP-violating phases.Comment: 28 pages, 16 figures, JHEP styl
Exploring improved holographic theories for QCD: Part II
This paper is a continuation of ArXiv:0707.1324 where improved holographic
theories for QCD were set up and explored. Here, the IR confining geometries
are classified and analyzed. They all end in a "good" (repulsive) singularity
in the IR. The glueball spectra are gaped and discrete, and they favorably
compare to the lattice data. Quite generally, confinement and discrete spectra
imply each other. Asymptotically linear glueball masses can also be achieved.
Asymptotic mass ratios of various glueballs with different spin also turn out
to be universal. Mesons dynamics is implemented via space filling D4-anti-D4
brane pairs. The associated tachyon dynamics is analyzed and chiral symmetry
breaking is shown. The dynamics of the RR axion is analyzed, and the
non-perturbative running of the QCD theta-angle is obtained. It is shown to
always vanish in the IR.Comment: 65+18 pages, 20 figures (v3) Some modifications in Appendix E
explaining in more detail the issue of initial conditions; typos corrected.
Published versio
Leptonic CP violation: zero, maximal or between the two extremes
Discovery of the CP-violation in the lepton sector is one of the challenges
of the particle physics. We search for possible principles, symmetries and
phenomenological relations that can lead to particular values of the
CP-violating Dirac phase, . In this connection we discuss two extreme
cases: the zero phase, , and the maximal CP-violation, , and relate them to the peculiar pattern of the neutrino mixing. The
maximal CP-violation can be related to the reflection
symmetry. We study various aspects of this symmetry and introduce a generalized
reflection symmetry that can lead to an arbitrary phase that depends on the
parameter of the symmetry transformation. The generalized reflection symmetry
predicts a simple relation between the Dirac and Majorana phases. We also
consider the possibility of certain relations between the CP-violating phases
in the quark and lepton sectors.Comment: 34 pages, no figures; v3: version appeared in JHE
Antihyperon-Production in Relativistic Heavy Ion Collision
Recently it has been shown that the observed antiproton yield in heavy-ion
collisions at CERN-SpS energies can be understood by multi-pionic interactions
which enforce local chemical equilibrium of the antiprotons with the nucleons
and pions. Here we show that antihyperons are driven towards local chemical
equilibrium with pions, nucleons and kaons on a timescale of less than 3 fm/c
when applying a similar argument for the antihyperons by considering the
inverse channel of annihilation reactions anti-Y + p to pions + kaons. These
multi-mesonic reactions easily explain the antihyperon yields at CERN-SpS
energies as advertised in pure thermal, hadronic models without the need of a
quark gluon plasma phase. In addition, the argument also applies for AGS
energies.Comment: 4 pages using RevTeX, 1 eps figur
Theoretical predictions for the direct detection of neutralino dark matter in the NMSSM
We analyse the direct detection of neutralino dark matter in the framework of
the Next-to-Minimal Supersymmetric Standard Model. After performing a detailed
analysis of the parameter space, taking into account all the available
constraints from LEPII, we compute the neutralino-nucleon cross section, and
compare the results with the sensitivity of detectors. We find that sizable
values for the detection cross section, within the reach of dark matter
detectors, are attainable in this framework. For example, neutralino-proton
cross sections compatible with the sensitivity of present experiments can be
obtained due to the exchange of very light Higgses with m_{h_1^0}\lsim 70
GeV. Such Higgses have a significant singlet composition, thus escaping
detection and being in agreement with accelerator data. The lightest neutralino
in these cases exhibits a large singlino-Higgsino composition, and a mass in
the range 50\lsim m_{\tilde\chi_1^0}\lsim 100 GeV.Comment: Final version to appear in JHEP. References added. LaTeX, 53 pages,
23 figure
Fragmentation of exotic oxygen isotopes
Abrasion-ablation models and the empirical EPAX parametrization of projectile fragmentation are described. Their cross section predictions are compared to recent data of the fragmentation of secondary beams of neutron-rich, unstable 19,20,21O isotopes at beam energies near 600 MeV/nucleon as well as data for stable 17,18O beams
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