556 research outputs found
A Few Finite Trigonometric Sums
Finite trigonometric sums occur in various branches of physics, mathematics,
and their applications. These sums may contain various powers of one or more
trigonometric functions. Sums with one trigonometric function are known,
however sums with products of trigonometric functions can get complicated and
may not have a simple expressions in a number of cases. Some of these sums have
interesting properties and can have amazingly simple value. However, only some
of them are available in literature. We obtain a number of such sums using
method of residues.Comment: 11 pages, added references, corrected typo
Gluon Fusion Contribution to Production at Hadron Colliders
We study the associated production of an electroweak vector boson and the
Higgs boson with a jet via gluon-gluon fusion. At the leading order, these
processes occur at one-loop level. The amplitudes of these one-loop processes
are gauge invariant and finite. Therefore, their contributions towards the
corresponding hadronic cross sections and kinematic distributions can be
calculated separately. We present results for the Large Hadron Collider and its
discussed upgrades. We find that the gluon-gluon one-loop process gives
dominant contribution to the production. We observe a destructive
interference effect in the amplitude. We also find that in the
high transverse momentum and central rapidity region, the production
cross section via gluon-gluon fusion becomes comparable to the cross section
contributions coming from quark-quark and quark-gluon channels.Comment: 12 pages, 6 figures, 2 tables. Version to appear in PL
Quantum mutual information and quantumness vectors for multi-qubit systems
We introduce a new information theoretic measure of quantum correlations for
multiparticle systems. We use a form of multivariate mutual information -- the
interaction information and generalize it to multiparticle quantum systems.
There are a number of different possible generalizations. We consider two of
them. One of them is related to the notion of quantum discord and the other to
the concept of quantum dissension. This new measure, called dissension vector,
is a set of numbers -- quantumness vector. This can be thought of as a
fine-grained measure, as opposed to measures that quantify some average quantum
properties of a system. These quantities quantify/characterize the correlations
present in multiparticle states. We consider some multiqubit states and find
that these quantities are responsive to different aspects of quantumness, and
correlations present in a state. We find that different dissension vectors can
track the correlations (both classical and quantum), or quantumness only. As
physical applications, we find that these vectors might be useful in several
information processing tasks. We consider the role of dissension vectors -- (a)
in deciding the security of BB84 protocol against an eavesdropper and (b) in
determining the possible role of correlations in the performance of Grover
search algorithm. Especially, in the Grover search algorithm, we find that
dissension vectors can detect the correlations and show the maximum
correlations when one expects.Comment: 18 pages 8 figures. Updated. Comments are welcom
Effect of Anomalous Couplings on the Associated Production of a Single Top Quark and a Higgs Boson at the LHC
We consider the production of a single top quark in association with a Higgs
boson at the LHC. In particular, we compute the cross sections for the
processes , , , , , ,
in the presence of the anomalous and couplings. We
find that the anomalous and couplings can enhance the cross
sections significantly. We also analyze a few signatures and show that, if
these couplings are indeed anomalous, then with enough data, one should be able
to observe the production of the Higgs boson in association with single top
quark.Comment: 15 pages, 4 figures, 5 tables. Typos fixed, reference added. Journal
versio
Production of a KK-graviton and a Vector Boson in ADD Model via Gluon fusion
In the models with large extra-dimensions, we examine the production of a
vector boson (\gamma / Z) in association with the Kaluza-Klein (KK) modes of
the graviton via gluon fusion. At the leading order, the process takes place
through quark-loop box and triangle diagrams and it is ultraviolate finite. We
report the results for the LHC. We also discuss the issues of anomaly and
decoupling of heavy quarks in the amplitude.Comment: 12 pages, 8 figures, some references and a note in the appendix adde
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