16352406
Large Multiplicity Gluon Production in QCD
We compute the approximate cross section σ (0) n for producing n − 2 resolved gluons in a gluon-gluon collision, using the Parke-Taylor formula regularized in a Lorentz invariant manner. We find, in double leading logarithm approximation, that σ n ≈ 1 s ( Ncαs 2π √ 12 ln(s/scut) n−2 , where √ scut is the minimum invariant mass for a resolved gluon pair. There is no factor of 1/(n− 2)! multiplying the expression. We present additional numerical results, and comment on their implications for perturbative calculations of n-jet cross sections at colliders. email: goldberg@neuhep.hex.northeastern.edu email: rosenfeld@neuhep.hex.northeastern.edu
120429995
PREDICTIONS FOR INCLUSIVE REACTIONS BASED ON A PARTON STRUCTURE OF HADRONS.
Abstract It is proposed that the asymptotic single-particle distributions f ( x )= x (d σ /d x ) in inclusive reactions should reflect the limiting longitudinal momentum distribution, ∼ νW 2 ( x ), of the hypothetical partons constituting a hadron. It is further argued that f ( x ) becomes, proportional to νW 2 ( x ) as x → 1. Predictions are then made for a large class of inclusive reactions based on our knowledge of νW 2 ( x ) from electroproduction data. For some of these (such as pp → π ± X), in which the predictions differ markedly from the Regge ones, present experiments distinctly favor ours.
119056773
THE MYSTERIOUS ULTRAHIGH ENERGY COSMIC RAY CLUSTERING
We examine the correlation between compact radio quasars (redshifts in the range z=0.3–2.2) and the arrival direction of ultrahigh energy cosmic rays forming clusters. Our Monte Carlo simulation reveals a statistically significant correlation on the AGASA sample: the chance probability of this effect being less than 1%. The implications of this result on the origin of ultrahigh energy cosmic rays are discussed.
13042203
Extensive air showers with TeV scale quantum gravity
One of the possible consequences of the existence of extra degrees of freedom beyond the electroweak scale is the increase of neutrino-nucleon cross sections ({sigma}{sub {nu}N}) beyond standard model predictions. At ultrahigh energies this may allow the existence of neutrino-initiated extensive air showers. In this paper, we examine the most relevant observables of such showers. Our analysis indicates that the future Pierre Auger Observatory could be potentially powerful in probing models with large compact dimensions.
119188244
LHC phenomenology of lowest massive Regge recurrences in the Randall-Sundrum orbifold
We consider string realizations of the Randall-Sundrum effective theory for electroweak symmetry breaking and explore the search for the lowest massive Regge excitation of the gluon and of the extra (color singlet) gauge boson inherent in D-brane constructions. In these curved backgrounds, the higher-spin Regge recurrences of standard model fields localized near the IR brane are warped down to close to the TeV range and hence can be produced at collider experiments. Assuming that the theory is weakly coupled, we make use of four gauge boson amplitudes evaluated near the first Regge pole to determine the discovery potential of LHC. We study the inclusive dijet mass spectrum in the central rapidity region |y{sub jet}| =}2.5 TeV. We find that with an integrated luminosity of 100 fb{sup -1}, the 5{sigma} discovery reach can be as high as 4.7 TeV. Observations of resonant structures in pp{yields}direct{gamma}+jet can provide interesting corroboration for string physics up to 3.0 TeV. We also study the ratio of dijet mass spectra at small and large scattering angles. We show that with the first fb{sup -1} such a ratio can probe lowest-lying Regge states for masses {approx}2.5 TeV.
10475979
Primordial Fluctuations from Gaugino Condensation
I present a model for inflation based on the gaugino-dilaton dynamics of supersymmetry breaking. The inflaton is the dimension–1 scalar field φ related to the gaugino condensate via λT λ = φ. Recent work in this area is used to obtain two significant results: (1) Scalar density fluctuations at second horizon crossing are generated on scale λ with amplitude
102780453
ELASTICALLY SCATTERED POLARIZATION OF 40-MeV PROTONS FROM DEUTERIUM
121567945
An optical model consistency condition between the regeneration phase and the real parts of the KON forward scattering amplitudes
Abstract Using just the magnitude of the regeneration amplitude we show that both the regeneration phase, ϕ r , and the sum of the ratios of the real to imaginary parts of the K O N forward scattering amplitudes, γ pn , can be determined for nuclei with zero or moderate neutron excess. We find: ϕ r = (43.5 ± 2.5) o ; γ pn = −0.73 ± 0.1 + 1.7 γ pn 〈 2.7 GeV /c 〉 = −0.65 ± 0.07 + 1.6 γ pn 〈 4.5 GeV /c 〉 , where γ pn is corresponding quantity for K O N scattering. Applications to regeneration in hydrogen and the ϕ-meson are discussed.