13 research outputs found
Generalized parton correlation functions for a spin-1/2 hadron
The fully unintegrated, off-diagonal quark-quark correlator for a spin-1/2
hadron is parameterized in terms of so-called generalized parton correlation
functions. Such objects, in particular, can be considered as mother
distributions of generalized parton distributions on the one hand and
transverse momentum dependent parton distributions on the other. Therefore, our
study provides new, model-independent insights into the recently proposed
nontrivial relations between generalized and transverse momentum dependent
parton distributions. We find that none of these relations can be promoted to a
model-independent status. As a by-product we obtain the first complete
classification of generalized parton distributions beyond leading twist. The
present paper is a natural extension of our previous corresponding analysis for
spin-0 hadrons.Comment: 41 pages, 3 figures; v2: added referenc
Diffractive upsilon production at the LHC
We compute the rate for diffractive upsilon meson production at the Tevatron
and the LHC. The upsilon is produced diffractively via the subprocess gamma + p
-> upsilon + p where the initial photon is radiated off an incoming proton (or
antiproton). We consider the possibility to use low angle proton detectors to
make a measurement of the gamma p cross-section and conclude that a measurement
of the cross-section at a centre of mass energy in excess of 1 TeV is possible
at the LHC. This is in the region where saturation effects are likely to reveal
themselves.Comment: 14 page
Central exclusive production of longlived gluinos at the LHC
We examine the possibility of producing gluino pairs at the LHC via the
exclusive reaction pp -> p+gluino+gluino+p in the case where the gluinos are
long lived. Such long lived gluinos are possible if the scalar super-partners
have large enough masses. We show that it may be possible to observe the
gluinos via their conversion to R-hadron jets and measure their mass to better
than 1% accuracy for masses below 350 GeV with 300/fb of data.Comment: 13 pages, 9 figures. Minor corrections to version
Forward Physics with Rapidity Gaps at the LHC
A rapidity gap program with great potential can be realized at the Large
Hadron Collider, LHC, by adding a few simple forward shower counters (FSCs)
along the beam line on both sides of the main central detectors, such as CMS.
Measurements of single diffractive cross sections down to the lowest masses can
be made with an efficient level-1 trigger. Exceptionally, the detectors also
make feasible the study of Central Diffractive Excitation, and in particular
the reaction g + g to g + g, in the color singlet channel, effectively using
the LHC as a gluon-gluon collider.Comment: 15 pages, 11 figure
Forward Jet Production at the Large Hadron Collider
At the Large Hadron Collider (LHC) it will become possible for the first time to investigate experimentally the forward region in hadron-hadron collisions via high-pT processes. In the LHC forward kinematics QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. We analyze the hadroproduction of forward jets in the framework of QCD high-energy factorization, which allows one to resum consistently both kinds of corrections to higher orders in QCD perturbation theory. We compute the short-distance matrix elements needed to evaluate the factorization formula at fully exclusive level. We discuss numerically dynamical features of multi-gluon emission at large angle encoded in the factorizing high-energy amplitudes
Detecting Higgs bosons in the bb decay channel using forward proton tagging at the LHC
A detailed study is presented of the search for Higgs bosons in the b-decay
channel in the central exclusive production process at the LHC. We present
results for proton tagging detectors at both 220m and 420m around ATLAS or CMS.
We consider two benchmark scenarios; a Standard Model (SM) Higgs boson and the
m_h^{max} scenario of the Minimal Supersymmetric Standard Model (MSSM).
Detector acceptance, smearing and event trigger strategies are considered. We
find that the SM Higgs will be challenging to observe in the b-jet channel
without improvements to the currently proposed experimental configuration, but
a neutral scalar MSSM Higgs Boson could be observable in the b-jet channel with
a significance of 3 sigma or greater within three years of data taking at all
luminosities between 2 x 10^{33} cm^{-2} s^{-1} and 10^{34} cm^{-2} s^{-1}, and
at 5 sigma or greater after three years in certain scenarios.Comment: 35 pages, 34 figure