ar X iv : h ep - p h / 06 10 34 5 v 2 1 3 Fe b 20 07 Suppressing Proton Decay By Separating Quarks And Leptons

ar X iv : h ep - t h / 06 02 23 8 v 1 2 3 Fe b 20 06 LTH / 689 UCB - PTH

In string theory, massless particles often originate from a symmetry breaking of a large gauge symmetry G to its subgroup H. The absence of dimension-4 proton decay in supersymmetric theories suggests that (D̄, L) are different from H̄(5̄) in their origins. In this article, we consider a possibility that they come from different irreducible components in g/h. Requiring that all the Yukawa coupling...

ar X iv : h ep - p h / 06 02 19 2 v 1 2 1 Fe b 20 06 UT - 06 - 01 Minimal Supergravity , Inflation , and All That

We consider an inflationary model in the hidden-sector broken supergravity with an effectively large cutoff. The inflaton decay into right-handed neutrinos naturally causes the observed baryon asymmetry of the universe with a reheating temperature low enough to avoid the gravitino overproduction. We emphasize that all the phenomenological requirements from cosmology and particle physics are sat...

ar X iv : h ep - p h / 06 02 21 5 v 1 2 3 Fe b 20 06 IPPP / 06 / 10 DCPT / 06 / 20 22 nd February 2006 Leading neutron spectra

It is shown that the observation of the spectra of leading neutrons from proton beams can be a good probe of absorptive and migration effects. We quantify how these effects modify the Reggeized pion-exchange description of the measurements of leading neutrons at HERA. We are able to obtain a satisfactory description of all the features of these data. We also briefly discuss the corresponding da...

ar X iv : h ep - p h / 96 02 31 9 v 1 1 5 Fe b 19

It is shown that the parity–violating deep–inelastic scatterings of unpolarized charged leptons on polarized protons, ℓ ∓ + P → (−) ν ℓ +X, could provide a sensitive test for the behavior and magnitude of the polarized strange–quark density in a proton. Below charm threshold these processes are also helpful to uniquely determine the magnitude of individual polarized parton distributions.

ar X iv : h ep - p h / 06 09 07 7 v 1 7 S ep 2 00 6 Hadron multiplicities in e + e − annihilation with heavy primary quarks