Dark Matter from Baryon Asymmetry

The measured densities of dark and baryonic matter are surprisingly close to each other, even though the baryon asymmetry and the dark matter are usually explained by unrelated mechanisms. We consider a scenario where the dark matter S is produced non-thermally from the decay of a messenger particle X, which carries the baryon number and compensates for the baryon asymmetry in the Universe, thereby establishing a connection between the baryonic and dark matter densities. We propose a simple model to realize this scenario, adding only a light singlet fermion S and a colored particle X which has a mass in the O(TeV) range and a lifetime to appear long-lived in collider detector. Therefore in hadron colliders the signal is similar to that of a stable or long-lived gluino in supersymmetric models.Comment: 12 pages; v2: bounds on the mass of the messenger particle are relaxed; conclusions unchanged. additional minor modification

Observations from the EEFIT-TDMRC mission to Banda Aceh, Indonesia to investigate the recovery from the 2004 Indian Ocean Tsunami

On 26th December 2004 a subduction zone earthquake of magnitude Mw 9.3 struck off the coast of Sumatra in Indonesia. A large area of the Indian Ocean seabed was vertically displaced, and as a result a tsunami wave was generated that went on to affect many countries around the world. One of the worst hit places was the Aceh province of Sumatra where the capital city, Banda Aceh, experienced serious ground shaking and significant sea water inundation. In Indonesia at least 126,732 people were killed, a further 93,652 people were confirmed missing and 533,770 people were displaced. In 2022, nearly 20 years on from the disaster, engineers and scientists from the UK Earthquake Engineering Field Investigation Team (EEFIT) and from the Indonesian Tsunami and Disaster Mitigation Research Centre (TDMRC) conducted a joint longterm recovery mission. This paper reflects on how a society rebuilds after such a devastating loss and what lessons can be learnt as a community for future disaster risk reduction. The scope of the paper includes the rapid assessment of post-disaster housing, community infrastructure and preparedness measures

Single gluino production in the R-parity lepton number violating MSSM at the LHC

We examine the $R_{p}$-violating signal of single gluino production associated with a charged lepton or neutrino at the large hadron collider (LHC), in the model of R-parity relaxed supersymmetric model. If the parameters in the ${\rlap/R}_p$ supersymmetric interactions are not too small, and the mass of gluino is considered in the range from several GeV (as the Lightest Supersymmetric Particle) to 800 GeV, the cross section of the single gluino production via Drell-Yan processes can be in the order of $10^2 \sim 10^3$ femto barn, and that via gluon fusion in the order of $10^{-1} \sim 10^3$ femto barn. If the gluino decay can be well detected in the CERN LHC, this process provides a prospective way to probe supersymmetry and $R_p$ violation.Comment: LaTex, 22 pages, 5 EPS file

The Impact of an Event-Triggered Video Intervention on Rural Teenage Driving

This study examines the ability of an event-triggered video system to extend parental involvement into the independent driving phase of newly licensed teen drivers. The system provides both immediate feedback and a 20-second video clip, giving the teen driver and their parent the opportunity to review and learn from their mistakes as well as good responses. The event-triggered video system was placed in the vehicles of 25 teen drivers (ages 16-17) for 57 weeks. The first nine weeks established a within-subject baseline; no parental or system feedback was given during this time. During the next 40 weeks, feedback was provided to the teen driver in the form of a blinking LED on the camera and a weekly report card mailed to the parents. The report showed the driver’s weekly and cumulative performance regarding unsafe behaviors and seatbelt use relative to the other participants. The last eight weeks was a second baseline period. Results revealed two distinct groups: one that triggered few events and one that triggered many events. Combining this emerging technology with parental weekly review of safety-relevant incidents resulted in a significant and lasting decrease in events for most of the teens that triggered many events

Fast Proton Decay

We consider proton decay in the testable flipped SU(5) X U(1)_X models with TeV-scale vector-like particles which can be realized in free fermionic string constructions and F-theory model building. We significantly improve upon the determination of light threshold effects from prior studies, and perform a fresh calculation of the second loop for the process p \to e^+ \pi^0 from the heavy gauge boson exchange. The cumulative result is comparatively fast proton decay, with a majority of the most plausible parameter space within reach of the future Hyper-Kamiokande and DUSEL experiments. Because the TeV-scale vector-like particles can be produced at the LHC, we predict a strong correlation between the most exciting particle physics experiments of the coming decade.Comment: RevTex4, 5 pages, 3 figures, 1 table, comments added, version to appear in PL

The Golden Strip of Correlated Top Quark, Gaugino, and Vectorlike Mass In No-Scale, No-Parameter F-SU(5)

We systematically establish the hyper-surface within the tan(beta), top quark mass m_t, universal gaugino mass M_1/2, and vectorlike mass M_V parameter volume which is compatible with the application of the No-Scale Supergravity boundary conditions, particularly the vanishing of the Higgs bilinear soft term B_mu, near to the Planck mass at the point M_F of ultimate F-lipped SU(5) unification. M_F is elevated from the penultimate partial unification near the traditional GUT scale at a mass M_32 by the inclusion of extra F-theory derived heavy vectorlike multiplets. We demonstrate that simultaneous adherence to all current experimental constraints, most importantly contributions to the muon anomalous magnetic moment (g-2)_mu, the branching ratio limit on (b \to s gamma), and the 7-year WMAP relic density measurement, dramatically reduces the allowed solutions to a highly non-trivial "golden strip" with tan(beta) \sim 15, m_t = 173.0-174.4 GeV, M_1/2 = 455-481 GeV, and M_V = 691-1020 GeV, effectively eliminating all extraneously tunable model parameters. We emphasize that the consonance of the theoretically viable m_t range with the experimentally established value is an independently correlated "postdiction". The predicted range of M_V is testable at the Large Hadron Collider (LHC). The partial lifetime for proton decay in the leading (e+|mu+) pi0 channels falls around 4.6 X 10^34 Y, testable at the future DUSEL and Hyper-Kamiokande facilities.Comment: V2, As accepted for publication in Physics Letters B; 7 pages, 3 figure

Moduli Dependent mu-Terms in a Heterotic Standard Model

In this paper, we present a formalism for computing the non-vanishing Higgs mu-terms in a heterotic standard model. This is accomplished by calculating the cubic product of the cohomology groups associated with the vector bundle moduli (phi), Higgs (H) and Higgs conjugate (Hbar) superfields. This leads to terms proportional to phi H Hbar in the low energy superpotential which, for non-zero moduli expectation values, generate moduli dependent mu-terms of the form H Hbar. It is found that these interactions are subject to two very restrictive selection rules, each arising from a Leray spectral sequence, which greatly reduce the number of moduli that can couple to Higgs-Higgs conjugate fields. We apply our formalism to a specific heterotic standard model vacuum. The non-vanishing cubic interactions phi H Hbar are explicitly computed in this context and shown to contain only four of the nineteen vector bundle moduli.Comment: 23 pages, LaTe

Searching for Strongly Interacting Massive Particles (SIMPs)

We consider laboratory experiments that can detect stable, neutral strongly interacting massive particles (SIMPs). We explore the SIMP annihilation cross section from its minimum value (restricted by cosmological bounds) to the barn range, and vary the mass values from a GeV to a TeV. We calculate, as a function of the SIMP-nucleon cross section, the minimum nucleon number A for which there should be binding in a nucleus. We consider accelerator mass spectrometry with a gold (A=200) target, and compute the likely abundance of anomalous gold nuclei if stable neutral SIMPs exist. We also consider the prospects and problems of detecting such particles at the Tevatron. We estimate optimistically that such detection might be possible for SIMPs with SIMP-nucleon cross sections larger than 0.1 millibarn and masses between 25 and 50 GeV.Comment: RevTeX, 10 pages, 3 figures; Minor updates to match published versio

An analysis of a Heavy Gluino LSP at CDF : The Heavy Gluino Window

In this paper we consider a heavy gluino to be the lightest supersymmetric particle [LSP]. We investigate the limits on the mass of a heavy gluino LSP, using the searches for excess events in the jets plus missing momentum channel in Run I. The neutral and charged R-hadrons, containing a heavy gluino LSP, have distinct signatures at the Fermilab Tevatron. The range of excluded gluino masses depends on whether the R-hadron is charged or neutral and the amount of energy deposited in the hadronic calorimeter. The latter depends on the energy loss per collision in the calorimeter and the number of collisions; where both quantities require a model for R-hadron- Nucleon scattering. We show how the excluded range of gluino mass depends on these parameters. We find that gluinos with mass in the range between $\sim 35$ GeV and $\sim 115$ GeV are excluded by CDF Run I data. Combined with previous results of Baer et al., which use LEP data to exclude the range 3 - 22$\sim$25 GeV, our result demonstrates that an allowed window for a heavy gluino with mass between 25 and 35 GeV is quite robust. Finally we discuss the relevant differences of our analysis of Tevatron data to that of Baer et al.Comment: 36 pages, 11 figures, added an acknowledgemen

Angular distributions in hard exclusive production of pion pairs

Using the leading order amplitudes of hard exclusive electroproduction of pion pairs we have analyzed the angular distribution of the two produced particles. At leading twist a pion pair can be produced only in an isovector or an isoscalar state. We show that certain components of the angular distribution only get contributions from the interference of the I=1 and the (much smaller) I=0 amplitude. Therefore our predictions prove to be a good probe of isospin zero pion pair production. We predict effects of a measurable size that could be observed at experiments like HERMES. We also discuss how hard exclusive pion pair production can provide us with new information on the effective chiral Lagrangian.Comment: 17 pages, version to appear in Phys. Rev.