10,611 research outputs found
Superfield Approach to Nilpotency and Absolute Anticommutativity of Conserved Charges: 2D non-Abelian 1-Form Gauge Theory
We exploit the theoretical strength of augmented version of superfield
approach (AVSA) to Becchi-Rouet-Stora-Tyutin (BRST) formalism to express the
nilpotency and absolute anticommutativity properties of the (anti-)BRST and
(anti-)co-BRST conserved charges for the two -dimensional (2D)
non-Abelian 1-form gauge theory (without any interaction with matter fields) in
the language of superspace variables, their derivatives and suitable
superfields. In the proof of absolute anticommutativity property, we invoke the
strength of Curci-Ferrari (CF) condition for the (anti-)BRST charges. No such
outside condition/restriction is required in the proof of absolute
anticommutativity of the (anti-)co-BRST conserved charges. The latter
observation (as well as other observations) connected with (anti-)co-BRST
symmetries and corresponding conserved charges are novel results of our present
investigation. We also discuss the (anti-)BRST and (anti-)co-BRST symmetry
invariance of the appropriate Lagrangian densities within the framework of
AVSA. In addition, we dwell a bit on the derivation of the above fermionic
(nilpotent) symmetries by applying the AVSA to BRST formaism where only the
(anti-)chiral superfields are used.Comment: LaTeX file, 33 pages, journal referenc
Solar Neutrinos: Spin Flavour Precession and LMA
The time dependence that appears to be hinted by the data from the first 13
years of the solar neutrino Gallium experiments is viewed as resulting from a
partial conversion of active neutrinos to light sterile ones through the
resonant interaction between the magnetic moment of the neutrino and a varying
solar field. A summary of the model and its predictions are presented for the
forthcoming experiments Borexino and LENS.Comment: 6 pages, 3 figures, contribution to 12th Lomonosov Conference in
Elementary Particle Physics, Moscow, Aug 24-31 (2005
Modified 2D Proca Theory: Revisited Under BRST and (Anti-)Chiral Superfield Formalisms
Within the framework of Becchi-Rouet-Stora-Tyutin (BRST) approach, we discuss
mainly the fermionic (i.e. off-shell nilpotent) (anti-)BRST, (anti-)co-BRST and
some discrete dual-symmetries of the appropriate Lagrangian densities for a two
(1+1)-dimensional (2D) modified Proca (i.e. a massive Abelian 1-form) theory
without any interaction with matter fields. One of the novel observations of
our present investigation is the existence of some kinds of restrictions in the
case of our present St\"{u}ckelberg-modified version of the 2D Proca theory
which is not like the standard Curci-Ferrari (CF)-condition of a non-Abelian
1-form gauge theory. Some kinds of similarities and a few differences between
them have been pointed out in our present investigation. To establish the
sanctity of the above off-shell nilpotent (anti-)BRST and (anti-)co-BRST
symmetries, we derive them by using our newly proposed (anti-)chiral superfield
formalism where a few specific and appropriate sets of invariant quantities
play a decisive role. We express the (anti-)BRST and (anti-)co-BRST conserved
charges in terms of the superfields that are obtained after the applications of
(anti-)BRST and (anti-)co-BRST invariant restrictions and prove their off-shell
nilpotency and absolute anticommutativity properties, too. Finally, we make
some comments on (i) the novelty of our restrictions/obstructions, and (ii) the
physics behind the negative kinetic term associated with the pseudo-scalar
field of our present theory.Comment: LaTeX file, 58 pages, Journal reference give
() spectroscopy using Cornell potential
The mass spectra and decay properties of heavy quarkonia are computed in
nonrelativistic quark-antiquark Cornell potential model. We have employed the
numerical solution of Schr\"odinger equation to obtain their mass spectra using
only four parameters namely quark mass (, ) and confinement strength
(, ). The spin hyperfine, spin-orbit and tensor
components of the one gluon exchange interaction are computed perturbatively to
determine the mass spectra of excited , , and states. Digamma,
digluon and dilepton decays of these mesons are computed using the model
parameters and numerical wave functions. The predicted spectroscopy and decay
properties for quarkonia are found to be consistent with available experimental
observations and results from other theoretical models. We also compute mass
spectra and life time of the meson without additional parameters. The
computed electromagnetic transition widths of heavy quarkonia and mesons
are in tune with available experimental data and other theoretical approaches
Phase 1 pilot study of e-mail support for people with long term conditions using the Internet.
BACKGROUND: Use of the Internet for people with Long Term Conditions (LTCs) can have a positive effect on knowledge, social support, behavioural and clinical outcomes, yet there is concern that a 'digital divide' prevents some patients from benefitting. While some patients do not have access to the Internet, others that do may still lack expertise or the confidence to make full use of it. The aim of this pilot study was to develop an intervention and test methods for a definitive randomised controlled trial (RCT) of anonymous personal online email support for patients in this latter group. METHODS: Recruitment success was evaluated by the number and appropriateness of participants recruited. A personalised e-health support intervention was developed. The provisional primary outcome was the extent to which the Internet affected the participants' confidence in dealing with their LTC. Primary outcome, seven process measures and two secondary outcomes measures were evaluated for completeness of data and sensitivity to detect changes. RESULTS: Thirty nine participants were recruited, 29 after personally receiving a leaflet, seven via email advertising, and three via leaflets left in waiting areas. Most participants (61%) were aged over 60. The majority (21/38) rated themselves as experienced Internet users although only 5/38 had used discussion forums for their LTC. Piloting the intervention identified support needed as: (i) technical help with some websites, (ii) advice about issues such as anonymity, (iii) help in judging information quality, (iv) identification of relevant information (via 'Information Prescriptions'), (v) motivational support to try new sites. Attrition was fairly high: 20/39 completed follow up questionnaires. Three process measures showed ceiling effects and two had too many missing values to be useable. CONCLUSION: E-health support is a promising way of addressing the problems faced by older generation e-health seekers. Face-to-face leaflet distribution recruited sufficient numbers but additional locations other than hospital should be tried to recruit Internet novices with LTCs. An RCT is feasible and necessary to evaluate the potential benefits of anonymous email support. Our methods could be used by other researchers studying Internet use by people with LTCs
Two Gallium data sets, spin flavour precession and KamLAND
We reexamine the possibility of a time modulation of the low energy solar
neutrino flux which is suggested by the average decrease of the Ga data in line
with our previous arguments. We perform two separate fits to the solar neutrino
data, one corresponding to 'high' and the other to 'low' Ga data, associated
with low and high solar activity respectively. We therefore consider an
alternative to the conventional solar+KamLAND fitting, which allows one to
explore the much wider range of the angle permitted by the
KamLAND fitting alone. We find a solution with parameters in which the 'high' and
the 'low' Ga rates lie far apart and are close to their central values and is
of comparable quality to the global best fit, where these rates lie much closer
to each other. This is an indication that the best fit in which all solar and
KamLAND data are used is not a good measure of the separation of the two Ga
data sets, as the information from the low energy neutrino modulation is
dissimulated in the wealth of data. Furthermore for the parameter set proposed
one obtains an equally good fit to the KamLAND energy spectrum and an even
better fit than the 'conventional' LMA one for the reactor antineutrino
survival probability as measured by KamLAND.Comment: V2: 15 pages, 3 eps figures, fit improved, final version to appear in
Journal of Physics
Constraints, Symmetry Transformations and Conserved Charges for Massless Abelian 3-Form Theory
We demonstrate the existence of the first-class constraints on the massless
Abelian 3-form theory which generate the classical gauge symmetry
transformations for this theory in any arbitrary D-dimension of spacetime. We
write down the explicit expression for the generator in terms of these
first-class constraints. Using the celebrated Noether theorem, corresponding to
the gauge symmetry transformations, we derive the Noether conserved current and
conserved charge. The latter is connected with the first-class constraints of
the theory in a subtle manner as we demonstrate clearly in our present
investigation. We comment on the first-class constraints within the framework
of Becchi-Rouet-Stora-Tyutin (BRST) formalism where the conserved (anti-)BRST
charges are the generalizations of the above generator for the classical gauge
symmetry transformations. The standard Noether conserved (anti-)BRST charges
are found to be non-nilpotent. We derive the nilpotent versions of the
(anti-)BRST charges. One of the interesting observations of our present
endeavor is the result that only the nilpotent versions of the conserved
(anti-)BRST charges lead to the annihilation of the physical states by the
operator form of the first-class constraints at the quantum level which is
consistent with the Dirac quantization condition for the systems that are
endowed with any kind of constraints.Comment: LaTeX file, 15 pages v2: major changes in the title and text,
references expanded, 21 page
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