Search results for "Direct product"
showing 10 items of 35 documents
Cohomology and contraction: The “non-relativistic” limit revisited
1984
In this note we reconsider the transition from P⊗U(1) to the N extended Galilei group \(\tilde G\)(m),first discussed by Saletan. To this aim, we first analyse the relations between the groups G⊗U(1) and \(\tilde G\)c , where G is a Lie group of trivial H o 2 (G,U(1)) cohomology and \(\tilde G\)c is a central extension of Gc (obtained from G by contraction) by U(1).
Large characteristically simple sections of finite groups
2021
In this paper we prove that if G is a group for which there are k non-Frattini chief factors isomorphic to a characteristically simple group A, then G has a normal section C/R that is the direct product of k minimal normal subgroups of G/R isomorphic to A. This is a significant extension of the notion of crown for isomorphic chief factors.
On the p-length of some finite p-soluble groups
2014
The main aim of this paper is to give structural information of a finite group of minimal order belonging to a subgroup-closed class of finite groups and whose $p$-length is greater than $1$, $p$ a prime number. Alternative proofs and improvements of recent results about the influence of minimal $p$-subgroups on the $p$-nilpotence and $p$-length of a finite group arise as consequences of our study
DirectX(3872)production ine+e−collisions
2014
Abstract Direct production of the charmonium-like state X ( 3872 ) in e + e − collisions is considered in the framework of the vector meson dominance model. An order-of-magnitude estimate for the width Γ ( X → e + e − ) is found to be ≳0.03 eV. The same approach applied to the χ c 1 charmonium decay predicts the corresponding width of the order 0.1 eV in agreement with earlier estimates. Experimental perspectives for the direct production of the 1 + + charmonia in e + e − collisions are briefly discussed.
Direct production of χc1 at BESIII
2019
The production of resonances in electron-positron annihilation has only been observed for states with quantum numbers JPC = 1−−, while C = +1 resonances appear only among the decay products. The direct production of the 1++ states could happen through two-photon or neutral current. Due to the smallness of the production rate, this process has never been verified experimentally. With the high luminosity and good performance of the BESIII experiment, a search of the direct production of the 1++ state in charmonium region, χc1, is undergoing with dedicated data samples around the χc1 mass. An overview of the data analysis will be presented.
Recoilles and resonant production of double-pion atoms
1992
Abstract We exploit two ideas found successful in the direct production of pionic atoms: recoilless condition and resonance production, in order to produce atomic systems with two bound π − . As an example of recoilless reaction we study π − + A X → p ( A−1 X , π − , π − ) , and as an example of resonant reaction we study π − X → ( π − π − X′) → π − X. In both cases the signals are found to be only a small fraction of the background indicating the big experimental difficulties that one is facing in producing these states.
A combined search for the standard model Higgs boson at s=1.96 TeV
2008
AbstractWe present new results of the search for WH→ℓνbb¯ production in pp¯ collisions at a center-of-mass energy of s=1.96 TeV, based on a dataset with integrated luminosity of 0.44 fb−1. We combine these new results with previously published searches by the D0 collaboration, for WH and ZH production analyzed in the E̸Tbb¯ final state, for ZH (→ℓ+ℓ−bb¯) production, for WH (→WWW) production, and for H (→WW) direct production. No signal-like excess is observed either in the WH analysis or in the combination of all D0 Higgs boson analyses. We set 95% C.L. (expected) upper limits on σ(pp¯→WH)×B(H→bb¯) ranging from 1.6 (2.2) pb to 1.9 (3.3) pb for Higgs boson masses between 105 and 145 GeV, to …
DIRECT PRODUCTION OF PIONIC ATOMS FROM RADIATIVE TRAPPING OF PIONS IN FLIGHT
1992
Abstract The reaction π−A→(πb−A)γ with Tπ=10−30 MeV producing a π− bound in the nucleus is studied to see its viability as an instrument to produce deeply bound pionic atoms in nuclei. We obtain cross sections of the order of tens of μb/ (sr MeV) for the production of the 1s and 2p states of 208Pb and negligible background from radiative pion capture and the other sources. The negligible background expected in the present reaction is unique among all other reactions so far proposed. The cross sections obtained are three orders of magnitude bigger than those in the best electromagnetic reactions previously proposed. The small background, the large cross sections and the present available flu…
Model building by coset space dimensional reduction in ten dimensions with direct product gauge symmetry
2009
14 pages.-- ISI article identifier:000264762400083.-- ArXiv pre-print avaible at:http://arxiv.org/abs/0812.0910
A star product in lattice gauge theory
1993
Abstract We consider a variant of the cup product of simplicial cochains and its applications in discrete formulations of non-abelian gauge theory. The standard geometrical ingredients in the continuum theory all have natural analogues on a simplicial complex when this star product is used to translate the wedge product of differential forms. Although the star product is non-associative, it is graded-commutative, and the coboundary operator acts as a deviation on the star algebra. As such, it is reminiscent of the star product considered in some approaches to closed string field theory, and we discuss applications to the three dimensional non-abelian Chern-Simons theory.