1,917 research outputs found
Gauge Invariant Noether's Theorem in Yang-Mills Theory
The gauge invariant definition of the spin dependent gluon distribution
function from first principle is necessary to study the proton spin crisis at
high energy colliders. In this paper we derive the gauge invariant Noether's
theorem in Yang-Mills theory by using combined Lorentz transformation plus
local non-abelian gauge transformation. We find that the definition of the
gauge invariant spin (or orbital) angular momentum of the Yang-Mills field does
not exist in Yang-Mills theory although the definition of the gauge invariant
spin (or orbital) angular momentum of the quark exists. We show that the gauge
invariant definition of the spin angular momentum of the Yang-Mills field in
the literature is not correct because of the non-vanishing boundary surface
term in Yang-Mills theory. We also find that the Belinfante-Rosenfeld tensor in
Yang-Mills theory is not required to obtain the symmetric and gauge invariant
energy-momentum tensor of the quark and the Yang-Mills field.Comment: 26 pages latex. arXiv admin note: text overlap with arXiv:1802.0286
String Theory at LHC Using Jet Production From String Regge Excitations vs String Balls
If we find extra dimensions in the second run of the LHC in the
collisions at = 14 TeV, then the string mass scale can be
TeV and we should produce QCD jets in partonic
collisions via string Regge excitations at the LHC. QCD jets can also be
produced from string balls via thermal radiation at Hagedorn temperature. In
this paper we study jet production from string Regge excitations vs string
balls in collisions at = 14 TeV at LHC and make a comparison
with the standard model QCD jets. We find that high jet production from
string Regge excitations can be larger than that from string balls and from
standard model QCD jets. We also find resonances in the jet production cross
section in string Regge excitation scenario which is absent in the other two
scenarios. Hence TeV scale high jets can be a good signature to study
string Regge excitations in the collisions at = 14 TeV at the
LHC.Comment: 14 pages latex, 4 .eps figures. arXiv admin note: text overlap with
arXiv:0902.376
Proof of Factorization of Production in Non-Equilibrium QCD at RHIC and LHC
suppression/production is one of the main signature of quark-gluon
plasma detection at RHIC and LHC. In order to study
suppression/production in high energy heavy-ion collisions at RHIC and LHC, one
needs to prove the factorization theorem of production in
non-equilibrium QCD medium, otherwise one will predict infinite cross section
of . In this paper we prove factorization theorem of
production in non-equilibrium QCD at RHIC and LHC at all order in coupling
constant.Comment: 29 pages latex. arXiv admin note: substantial text overlap with
arXiv:1509.01148; text overlap with arXiv:1506.02593, arXiv:1506.02651,
arXiv:1508.0119
Correct Definition of the Gluon Distribution Function at High Energy Colliders
Unlike QED, since F_{\mu \nu}^a(x)F^{\mu \nu a}(0) in QCD contains cubic and
quartic powers of the gluon field the present definition of the gluon
distribution function at high energy colliders is not consistent with the
number operator interpretation of the gluon. In this paper we derive the
correct definition of the gluon distribution function at high energy colliders
from first principles which is consistent with the number operator
interpretation of the gluon and is gauge invariant and is consistent with the
factorization theorem in QCD.Comment: 32 pages latex. arXiv admin note: substantial text overlap with
arXiv:1506.0259
Momentum Sum Rule Is Violated in The Operator Product Expansion in QCD At The High Energy Colliders
To prove the momentum sum rule in the operator product expansion (OPE) in QCD
at high energy colliders it is assumed that
where is the momentum eigenstate of the hadron with momentum
and is the component of the gauge invariant color
singlet energy-momentum tensor density operator of all
the quarks plus antiquarks plus gluons inside the hadron . However, in this
paper, we show that this relation is correct
if is the energy-momentum tensor density operator of
the hadron but this relation is not correct
if is the gauge invariant color singlet energy-momentum
tensor density operator of all the quarks plus antiquarks plus gluons inside
the hadron. Hence we find that the momentum sum rule is violated in the
operator product expansion (OPE) in QCD at high energy colliders.Comment: 11 pages late
Operator Product Expansion in QCD Is Not Consistent With Quantum Field Theory For Gluon Distribution Function
Since the operator product expansion (OPE) is applicable at short distance
the OPE in QCD does not solve the long distance confinement problem involving
hadron in QCD where the non-perturbative QCD is applicable. In this paper we
show that the gauge invariant definition of the non-perturbative gluon
distribution function inside the hadron consistent with the operator product
expansion (OPE) in QCD at high energy colliders is not consistent with the
gauge invariant definition of the non-perturbative gluon distribution function
in the quantum field theory.Comment: 17 pages late
Non-Perturbative Quark-Antiquark Production From a Constant Chromo-Electric Field via the Schwinger Mechanism
We obtain an exact result for the non-perturbative quark (antiquark)
production rate and its p_T distribution from a constant SU(3) chromo-electric
field E^a with arbitary color index by directly evaluating the path
integral. Unlike the WKB tunneling result, which depends only on one gauge
invariant quantity |E|, the strength of the chromo-electric field, we find that
the exact result for the p_T distribution for quark (antiquark) production rate
depends on two independent Casimir (gauge) invariants, E^aE^a and
[d_{abc}E^aE^bE^c]^2.Comment: 7 pages latex. To appear in Phys. Rev.
String Theory at LHC Using Supersymmetry Production From String Balls
If extra dimensions are found in the second run of LHC in the collisions
at = 14 TeV then the string scale can be TeV, and we should
produce string balls at LHC. In this paper we study supersymmetry (squark and
gluino) production from string balls at LHC in collisions at =
14 TeV and compare that with the parton fusion results using pQCD. We find
significant squark and gluino production from string balls at LHC which is
comparable to parton fusion pQCD results. Hence, in the absence of black hole
production at LHC, an enhancement in supersymmetry production can be a
signature of TeV scale string physics at LHC.Comment: 18 pages latex, 7 .eps figures. arXiv admin note: substantial text
overlap with arXiv:0902.3764, arXiv:1508.0635
String Theory at LHC Using Higgs Production and Decay From String Balls
We study Higgs production and decay from TeV scale string balls in
collisions at = 14 TeV at LHC. We present the results of total cross
section of diphotons, invariant mass distribution of the diphotons and
distribution of the diphotons and pairs from Higgs from string balls at
LHC. We find that the invariant mass distribution of diphotons from Higgs from
string balls is not very sensitive to the increase in diphoton invariant mass.
We find that for string mass scale =2.5 TeV, which is the lower limit of
the string mass scale set by the recent CMS collaboration at LHC, the
of high ( 450 GeV) diphotons and pairs
produced from Higgs from string balls is larger than that from standard model
Higgs. Hence in the absence of black hole production at LHC an enhancement of
high diphotons and pairs at LHC can be useful signatures for string
theory at LHC. Since the matrix element for Higgs production in parton-parton
collisions via string regge excitations is not available we compute
of photon production from string regge excitations and
make a comparison with that from string balls at LHC. We find that for string
mass scale = 2.5 TeV the from string
regge excitations is larger than that from string balls and black holes at LHC.Comment: Title changed, New results on string regge excitations added, 18
pages latex, 7 figures, Accepted for publication in JHE
Correct Definition of Color Singlet P-Wave Non-Perturbative Matrix Element of Heavy Quarkonium Production
Recently we have proved factorization of infrared divergences in NRQCD S-wave
heavy quarkonium production at high energy colliders at all orders in coupling
constant. One of the problem which still exists in the higher order pQCD
calculation of color singlet P-wave heavy quarkonium production/anihillation is
the appearance of non-canceling infrared divergences due to real soft gluons
exchange, although no such infrared divergences are present in the color
singlet S-wave heavy quarkonium. In this paper we find that since the
non-perturbative matrix element of the color singlet P-wave heavy quarkonium
production contains derivative operators, the gauge links are necessary to make
it gauge invariant and be consistent with the factorization of such
non-canceling infrared divergences at all orders in coupling constant.Comment: 18 pages latex, Final Version, Accepted for Publication in JHE
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