4,255 research outputs found
Heavy Quarkonium States with the Holographic Potential
The quarkonium states in a quark-gluon plasma is examined with the heavy
quark potential implied by the holographic principle. Both the vanila
AdS-Schwarzschild metric and the one with an infrared cutoff are considered.
The dissociation temperature is calculated by solving the Schr\"o dinger
equation of the potential model. In the case of the AdS-Schwarzschild metric
with a IR cutoff, the dissociation temperatures for and
with the U-ansatz of the potential are found to agree with the lattice results
within a factor of two.Comment: 9 pages with 2 figues in Revte
Suggestion, hypnosis and hypnotherapy: a survey of use, knowledge and attitudes of anaesthetists
Publisher's copy made available with the permission of the publisher © Australian Society of AnaesthetistsClinical hypnosis is a skill of using words and gestures (frequently called suggestions) in particular ways to achieve specific outcomes. It is being increasingly recognised as a useful intervention for managing a range of symptoms, especially pain and anxiety. We surveyed all 317 South Australian Fellows and trainees registered with ANZCA to determine their use, knowledge of, and attitudes towards positive suggestion, hypnosis and hypnotherapy in their anaesthesia practice. The response rate was 218 anaesthetists (69%). The majority of respondents (63%) rated their level of knowledge on this topic as below average. Forty-eight per cent of respondents indicated that there was a role for hypnotherapy in clinical anaesthesia, particularly in areas seen as traditional targets for the modality, i.e. pain and anxiety states. Nearly half of the anaesthetists supported the use of hypnotherapy and positive suggestions within clinical anaesthesia. Those respondents who had experience of clinical hypnotherapy were more likely to support hypnosis teaching at undergraduate or postgraduate level when compared with those with no experience.http://www.aaic.net.au/Article.asp?D=200408
Probing Yukawa Unification with K and B Mixing
We consider corrections to the unification of down-quark and charged-lepton
Yukawa couplings in supersymmetric GUTs, which links the large nu_tau-nu_mu
mixing angle to b -> s transitions. These corrections generically occur in
simple grand-unified models with small Higgs representations and affect s -> d
and b -> d transitions via the mixing of the corresponding right-handed
superpartners. On the basis of a specific SUSY-SO(10) model, we analyze the
constraints from K-Kbar and B-Bbar mixing on the additional
\tilde{d}_R-\tilde{s}_R rotation angle theta. We find that epsilon_K already
sets a stringent bound on theta, theta^{max}=O(1 degree), indicating a very
specific flavor structure of the correction operators. The impact of the large
neutrino mixings on the unitarity triangle analysis is also briefly discussed,
as well as their ability to account for the sizeable CP-violating phase
observed recently in B_s -> psi phi decays.Comment: 19 pages. Discussion in Sec. 5.2 slightly extended; minor numerical
modifications in Secs. 5.1 to 5.4, conclusions unchanged. Version to appear
in JHE
eta_c production at the Large Hadron Collider
We have studied the production of the 1S_0 charmonium state, eta_c, at the
Large Hadron Collider (LHC) in the framework of Non-Relativistic Quantum
Chromodynamics (NRQCD) using heavy-quark symmetry. We find that NRQCD predicts
a large production cross-section for this resonance at the LHC even after
taking account the small branching ratio of eta_c into two photons. We show
that it will be possible to test NRQCD through its predictions for eta_c, with
the statistics that will be achieved at the early stage of the LHC, running at
a center of mass energy of 7 TeV with an integrated luminosity of 100 pb^{-1}Comment: 8 pages, 2 figure
The MSSM fine tuning problem: a way out
As is well known, electroweak breaking in the MSSM requires substantial
fine-tuning, mainly due to the smallness of the tree-level Higgs quartic
coupling, lambda_tree. Hence the fine tuning is efficiently reduced in
supersymmetric models with larger lambda_tree, as happens naturally when the
breaking of SUSY occurs at a low scale (not far from the TeV). We show, in
general and with specific examples, that a dramatic improvement of the fine
tuning (so that there is virtually no fine-tuning) is indeed a very common
feature of these scenarios for wide ranges of tan(beta) and the Higgs mass
(which can be as large as several hundred GeV if desired, but this is not
necessary). The supersymmetric flavour problems are also drastically improved
due to the absence of RG cross-talk between soft mass parameters.Comment: 28 pages, 9 PS figures, LaTeX Published versio
Charmless hadronic decays in the perturbative QCD approach
In this work, we calculate the branching ratios (BRs) and the polarization
fractions of sixty two charmless two-body meson decays into final states
involving one vector and one axial-vector meson () or two axial-vector
mesons() within the framework of perturbative QCD (pQCD) approach
systematically, where is either a or axial-vector meson.
All considered decay channels can only occur through the annihilation
topologies in the standard model. Based on the perturbative calculations and
phenomenological analysis, we find the following results: (i) the CP-averaged
BRs of the considered sixty two decays are in the range of to
; (ii) since the behavior for meson is much different from
that of meson, the BRs of decays are
generally larger than that of decays in the
pQCD approach; (iii) many considered decays modes, such as , , etc, have sizable BRs within the reach of the LHCb
experiments; (iv) the longitudinal polarization fractions of most considered
decays are large and play the dominant role; (v) the pQCD predictions for
several decays involving mixtures of and/or mesons are highly
sensitive to the values of the mixing angles, which will be tested by the
ongoing LHC and forthcoming Super-B experiments; (vi) the CP-violating
asymmetries of these considered decays are absent in the standard model
because only one type tree operator is involved.Comment: 31 pages, 1 figur
Physics Beyond the Standard Model and Cosmological Connections: A Summary from LCWS 06
The International Linear Collider (ILC) is likely to provide us important
insights into the sector of physics that may supersede our current paradigm
viz., the Standard Model. In anticipation of the possibility that the ILC may
come up in the middle of the next decade, several groups are vigourously
investigating its potential to explore this new sector of physics. The Linear
Collider Workshop in Bangalore (LCWS06) had several presentations of such
studies which looked at supersymmetry, extra dimensions and other exotic
possibilities which the ILC may help us discover or understand. Some papers
also looked at the understanding of cosmology that may emerge from studies at
the ILC. This paper summarises these presentations.Comment: 8 pages (including cover page) LaTeX, Summary talk presented at the
International Linear Collider Workshop in Bangalore, India in March 200
B Physics at the Z0 Resonance
B physics results from e+ e- annihilation at the Z0 resonance are reviewed. A
vast program is summarised, including the study of B+, B0d, B0s and b baryon
lifetimes, the time dependence of B0d and B0s oscillations, the width
difference in the B0s system, and the measurements of the magnitudes of the CKM
matrix elements Vcb and Vub.Comment: 17 pages, 8 figures, presented at the UK Phenomenology Workshop on
Heavy Flavour and CP Violation, 17-22 September 200
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