2,584 research outputs found
Anapole Moment and Other Constraints on the Strangeness Conserving Hadronic Weak Interaction
Standard analyses of low-energy NN and nuclear parity-violating observables
have been based on a pi-, rho-, and omega-exchange model capable of describing
all five independent s-p partial waves. Here a parallel analysis is performed
for the one-body, exchange-current, and nuclear polarization contributions to
the anapole moments of 133Cs and 205Tl. The resulting constraints are not
consistent, though there remains some degree of uncertainty in the nuclear
structure analysis of the atomic moments.Comment: Revtex, 10 pages, 1 figur
Precision Study of Positronium: Testing Bound State QED Theory
As an unstable light pure leptonic system, positronium is a very specific
probe atom to test bound state QED. In contrast to ordinary QED for free
leptons, the bound state QED theory is not so well understood and bound state
approaches deserve highly accurate tests. We present a brief overview of
precision studies of positronium paying special attention to uncertainties of
theory as well as comparison of theory and experiment. We also consider in
detail advantages and disadvantages of positronium tests compared to other QED
experiments.Comment: A talk presented at Workshop on Positronium Physics (ETH Zurich, May
30-31, 2003
Manifestation of the Nuclear Anapole Moment in M1 Transitions in Thallium
We calculate nuclear spin-dependent parity non-conserving -amplitudes for
optical transition and for hyperfine transition
in Tl. Experimental limit on the former amplitude
placed by Vetter et al. [PRL, 74, 2658 (1995)] corresponds to the anapole
moment constant . Experiment on the hyperfine
transition can give direct measurement of the spin-dependent amplitude, because
spin-independent amplitude turns to zero.Comment: 4 pages, LaTeX2e, uses revtex4.cl
Negative group delay for Dirac particles traveling through a potential well
The properties of group delay for Dirac particles traveling through a
potential well are investigated. A necessary condition is put forward for the
group delay to be negative. It is shown that this negative group delay is
closely related to its anomalous dependence on the width of the potential well.
In order to demonstrate the validity of stationary-phase approach, numerical
simulations are made for Gaussian-shaped temporal wave packets. A restriction
to the potential-well's width is obtained that is necessary for the wave packet
to remain distortionless in the travelling. Numerical comparison shows that the
relativistic group delay is larger than its corresponding non-relativistic one.Comment: 10 pages, 5 figure
Vlasov Description Of Dense Quark Matter
We discuss properties of quark matter at finite baryon densities and zero
temperature in a Vlasov approach. We use a screened interquark Richardson's
potential consistent with the indications of Lattice QCD calculations.
We analyze the choices of the quark masses and the parameters entering the
potential which reproduce the binding energy (B.E.) of infinite nuclear matter.
There is a transition from nuclear to quark matter at densities 5 times above
normal nuclear matter density. The transition could be revealed from the
determination of the position of the shifted meson masses in dense baryonic
matter. A scaling form of the meson masses in dense matter is given.Comment: 15 pages 4 figure
Atomic Parity Violation and Precision Electroweak Physics - An Updated Analysis
A new analysis of parity violation in atomic cesium has led to the improved
value of the weak charge, . The implications
of this result for constraining the Peskin-Takeuchi parameters S and T and for
guiding searches for new Z bosons are discussed.Comment: 8 pages, LaTeX, 3 figures, Submitted to Physical Review D. Updated
experimental inputs and references; clarification of notatio
Coherent amplification of classical pion fields during the cooling of droplets of quark plasma
In the framework of the linear sigma model, we study the time evolution of a
system of classical and pion fields coupled to quarks. For this
purpose we solve numerically the classical transport equation for relativistic
quarks coupled to the nonlinear Klein-Gordon equations for the meson fields. We
examine evolution starting from variety of initial conditions corresponding to
spherical droplets of hot quark matter, which might mimic the behaviour of a
quark plasma produced in high-energy nucleus-nucleus collisions. For large
droplets we find a strong amplification of the pion field that oscillates in
time. This leads to a coherent production of pions with a particular isospin
and so would have similar observable effects to a disoriented chiral condensate
which various authors have suggested might be a signal of the chiral phase
transition. The mechanism for amplification of the pion field found here does
not rely on this phase transition and is better thought of as a "pion laser"
which is driven by large oscillations of the field.Comment: 12 TeX pages + 20 postscript figures, psfig styl
Radium ion: A possible candidate for measuring atomic parity violation
Single trapped and laser cooled Radium ion as a possible candidate for
measuring the parity violation induced frequency shift has been discussed here.
Even though the technique to be used is similar to that proposed by Fortson
[1], Radium has its own advantages and disadvantages. The most attractive part
of Radium ion as compared to that of Barium ion is its mass which comes along
with added complexity of instability as well as other issues which are
discussed hereComment: Conference proceedin
Role of Present and Future Atomic Parity Violation Experiments in Precision Electroweak Tests
Recent reanalyses of the atomic physics effects on the weak charge in cesium
have led to a value in much closer agreement with predictions of the Standard
Model. We review precision electroweak tests, their implications for upper
bounds on the mass of the Higgs boson, possible ways in which these bounds may
be circumvented, and the requirements placed upon accuracy of future atomic
parity violation experiments by these considerations.Comment: 10 pages, LaTeX, 1 figure, to be submitted to Physical Review D, new
data on neutrino deep inelastic scattering include
Analgesic Effects of GpTx-1, PF-04856264 and CNV1014802 in a Mouse Model of NaV1.7-Mediated Pain
Loss-of-function mutations of NaV1.7 lead to congenital insensitivity to pain, a rare condition resulting in individuals who are otherwise normal except for the inability to sense pain, making pharmacological inhibition of NaV1.7 a promising therapeutic strategy for the treatment of pain. We characterized a novel mouse model of NaV1.7-mediated pain based on intraplantar injection of the scorpion toxin OD1, which is suitable for rapid in vivo profiling of NaV1.7 inhibitors. Intraplantar injection of OD1 caused spontaneous pain behaviors, which were reversed by co-injection with NaV1.7 inhibitors and significantly reduced in NaV1.7â/â mice. To validate the use of the model for profiling NaV1.7 inhibitors, we determined the NaV selectivity and tested the efficacy of the reported NaV1.7 inhibitors GpTx-1, PF-04856264 and CNV1014802 (raxatrigine). GpTx-1 selectively inhibited NaV1.7 and was effective when co-administered with OD1, but lacked efficacy when delivered systemically. PF-04856264 state-dependently and selectively inhibited NaV1.7 and significantly reduced OD1-induced spontaneous pain when delivered locally and systemically. CNV1014802 state-dependently, but non-selectively, inhibited NaV channels and was only effective in the OD1 model when delivered systemically. Our novel model of NaV1.7-mediated pain based on intraplantar injection of OD1 is thus suitable for the rapid in vivo characterization of the analgesic efficacy of NaV1.7 inhibitors
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