406,083 research outputs found
Study of J /ψ production in Jets
The production of J/ψ mesons in jets is studied in the forward region of proton-proton collisions using data collected with the LHCb detector at a center-of-mass energy of 13 TeV. The fraction of the jet transverse momentum carried by the J/ψ meson, z(J/ψ)≡pT(J/ψ)/pT(jet), is measured using jets with pT(jet)>20 GeV in the pseudorapidity range 2.5<η(jet)<4.0. The observed z(J/ψ)distribution for J/ψ mesons produced in b-hadron decays is consistent with expectations. However, the results for prompt J/ψ production do not agree with predictions based on fixed-order nonrelativistic QCD. This is the first measurement of the pT fraction carried by prompt J/ψ mesons in jets at any experiment
On blocks of strongly p-solvable groups
We prove that a block of a finite strongly p-solvable group G with defect group P is Morita equivalent to its corresponding block of NG(Z(J(P))) via a bimodule with endo-permutation source
More three-point correlators of giant magnons with finite size
In the framework of the semiclassical approach, we compute the normalized
structure constants in three-point correlation functions, when two of the
vertex operators correspond to heavy string states, while the third vertex
corresponds to a light state. This is done for the case when the heavy string
states are finite-size giant magnons with one or two angular momenta, and for
two different choices of the light state, corresponding to dilaton operator and
primary scalar operator. The relevant operators in the dual gauge theory are
Tr(F_{\mu\nu}^2 Z^j+...) and Tr(Z^j). We first consider the case of AdS_5 x S^5
and N = 4 super Yang-Mills. Then we extend the obtained results to the
gamma-deformed AdS_5 x S^5_\gamma, dual to N = 1 super Yang-Mills theory,
arising as an exactly marginal deformation of N = 4 super Yang-Mills.Comment: 14 pages, no figure
FeH Absorption in the Near-Infrared Spectra of Late M and L Dwarfs
We present medium-resolution z-, J-, and H-band spectra of four late-type
dwarfs with spectral types ranging from M8 to L7.5. In an attempt to determine
the origin of numerous weak absorption features throughout their near-infrared
spectra, and motivated by the recent tentative identification of the E 4\Pi- A
^4\Pi system of FeH near 1.6 microns in umbral and cool star spectra, we have
compared the dwarf spectra to a laboratory FeH emission spectrum. We have
identified nearly 100 FeH absorption features in the z-, J-, and H-band spectra
of the dwarfs. In particular, we have identified 34 features which dominate the
appearance of the H-band spectra of the dwarfs and which appear in the
laboratory FeH spectrum. Finally, all of the features are either weaker or
absent in the spectrum of the L7.5 dwarf which is consistent with the weakening
of the known FeH bandheads in the spectra of the latest L dwarfs.Comment: accepted by Ap
Proper motion L and T dwarf candidate members of the Pleiades
We present the results of a deep optical-near-infrared multi-epoch survey
covering 2.5 square degrees of the Pleiades open star cluster to search for new
very-low-mass brown dwarf members. A significant (~ 5 year) epoch difference
exists between the optical (CFH12k I-, Z-band) and near infrared (UKIRT WFCAM
J-band) observations. We construct I,I-Z and Z,Z-J colour magnitude diagrams to
select candidate cluster members. Proper motions are computed for all candidate
members and compared to the background field objects to further refine the
sample. We recover all known cluster members within the area of our survey. In
addition, we have discovered 9 new candidate brown dwarf cluster members. The 7
faintest candidates have red Z-J colours and show blue near-infrared colours.
These are consistent with being L and T-type Pleiads. Theoretical models
predict their masses to be around 11 Jupiter masses.
There is 1 errata for this paperComment: 12 pages, 9 figures, 4 tables, accepted for publication in MNRAS
Errata: 1 tabl
The Elliptic Algebra U_{q,p}(sl_N^) and the Deformation of W_N Algebra
After reviewing the recent results on the Drinfeld realization of the face
type elliptic quantum group B_{q,lambda}(sl_N^) by the elliptic algebra
U_{q,p}(sl_N^), we investigate a fusion of the vertex operators of
U_{q,p}(sl_N^). The basic generating functions \Lambda_j(z) (j=1,2,.. N-1) of
the deformed W_N algebra are derived explicitly.Comment: 15 pages, to appear in Journal of physics A special issue - RAQIS0
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