Bino Dark Matter and Big Bang Nucleosynthesis in the Constrained E6SSM with Massless Inert Singlinos

We discuss a new variant of the E6 inspired supersymmetric standard model (E6SSM) in which the two inert singlinos are exactly massless and the dark matter candidate has a dominant bino component. A successful relic density is achieved via a novel mechanism in which the bino scatters inelastically into heavier inert Higgsinos during the time of thermal freeze-out. The two massless inert singlinos contribute to the effective number of neutrino species at the time of Big Bang Nucleosynthesis, where the precise contribution depends on the mass of the Z' which keeps them in equilibrium. For example for mZ' > 1300 GeV we find Neff \approx 3.2, where the smallness of the additional contribution is due to entropy dilution. We study a few benchmark points in the constrained E6SSM with massless inert singlinos to illustrate this new scenario.Comment: 24 pages, revised for publication in JHE

Illicit purchasing and use of flavour accessories after the European Union menthol cigarette ban: Findings from the 2020-2021 ITC Netherlands Surveys

Background The 2020 European Union (EU) menthol cigarette ban increased quitting among pre-ban menthol smokers in the Netherlands, but some reported continuing to smoke menthol cigarettes. This study examined three possible explanations for post-ban menthol use—(i) illicit purchasing, (ii) use of flavour accessories and (iii) use of non-menthol replacement brands marketed for menthol smokers. Methods Data were from the ITC Netherlands Cohort Surveys among adult smokers before the menthol ban (Wave 1: February–March 2020, N = 2067) and after the ban (Wave 2: September–November 2020, N = 1752; Wave 3: June–July 2021, N = 1721). Bivariate, logistic regression and generalized estimating equation model analyses were conducted on weighted data. Results Illicit purchasing remained low from pre-ban (2.4%, 95% CI: 1.8–3.2, Wave 1) to post-ban (1.7%, 1.2–2.5%, Wave 3), with no difference between menthol and non-menthol smokers from Wave 1 to Wave 3. About 4.4% of post-ban menthol smokers last purchased their usual brand outside of the EU and 3.6% from the internet; 42.5% of post-ban menthol smokers and 4.4% of smokers overall reported using flavour accessories, with greater odds among those aged 25–39 years vs. 55+ (aOR = 3.16, P = 0.002). Approximately 70% of post-ban smokers who reported using a menthol brand were actually using a non-menthol replacement brand. Conclusions There was no increase in illicit purchasing or of smuggling outside the EU among menthol and non-menthol smokers in the Netherlands 1 year after the EU menthol cigarette ban. Use of flavour accessories and non-menthol replacement brands best explain post-ban menthol use, suggesting the need to ban accessories and ensure industry compliance

A preferential attachment model with random initial degrees

In this paper, a random graph process ${G(t)}_{t\geq 1}$ is studied and its degree sequence is analyzed. Let $(W_t)_{t\geq 1}$ be an i.i.d. sequence. The graph process is defined so that, at each integer time $t$, a new vertex, with $W_t$ edges attached to it, is added to the graph. The new edges added at time t are then preferentially connected to older vertices, i.e., conditionally on $G(t-1)$, the probability that a given edge is connected to vertex i is proportional to $d_i(t-1)+\delta$, where $d_i(t-1)$ is the degree of vertex $i$ at time $t-1$, independently of the other edges. The main result is that the asymptotical degree sequence for this process is a power law with exponent $\tau=\min\{\tau_{W}, \tau_{P}\}$, where $\tau_{W}$ is the power-law exponent of the initial degrees $(W_t)_{t\geq 1}$ and $\tau_{P}$ the exponent predicted by pure preferential attachment. This result extends previous work by Cooper and Frieze, which is surveyed.Comment: In the published form of the paper, the proof of Proposition 2.1 is incomplete. This version contains the complete proo

Impact of R-Parity Violation on Supersymmetry Searches at the Tevatron

We evaluate cross sections for \eslt, 1$\ell$ and various dilepton and multilepton event topologies that result from the simultaneous production of all sparticles at the Tevatron collider, both within the minimal model framework as well as in two different $R$-parity violating scenarios. Our analysis assumes that these $R$-violating couplings are small, and that their sole effect is to cause the lightest supersymmetric particle to decay inside the detector. We reassess future strategies for sparticle searches at the Tevatron, and quantify by how much the various signals for supersymmetry could differ from their minimal model expectations, if $R$-parity is not conserved due to either baryon number or lepton number violating operators. We also evaluate the Tevatron reach in $m_{\tg}$ for the various models, and find that rate-limited multilepton signals ultimately provide the largest reach for both $R$-parity conserving and $R$-parity violating cases.Comment: preprint nos. FSU-HEP-941001, UR-1387, ER-40685-836 and UH-511-807-94, 13 pages (REVTEX) plus 3 uuencoded figures attache

A Brownian particle in a microscopic periodic potential

We study a model for a massive test particle in a microscopic periodic potential and interacting with a reservoir of light particles. In the regime considered, the fluctuations in the test particle's momentum resulting from collisions typically outweigh the shifts in momentum generated by the periodic force, and so the force is effectively a perturbative contribution. The mathematical starting point is an idealized reduced dynamics for the test particle given by a linear Boltzmann equation. In the limit that the mass ratio of a single reservoir particle to the test particle tends to zero, we show that there is convergence to the Ornstein-Uhlenbeck process under the standard normalizations for the test particle variables. Our analysis is primarily directed towards bounding the perturbative effect of the periodic potential on the particle's momentum.Comment: 60 pages. We reorganized the article and made a few simplifications of the conten

A Way to Reopen the Window for Electroweak Baryogenesis

We reanalyse the sphaleron bound of electroweak baryogenesis when allowing deviations to the Friedmann equation. These modifications are well motivated in the context of brane cosmology where they appear without being in conflict with major experimental constraints on four-dimensional gravity. While suppressed at the time of nucleosynthesis, these corrections can dominate at the time of the electroweak phase transition and in certain cases provide the amount of expansion needed to freeze out the baryon asymmetry without requiring a strongly first order phase transition. The sphaleron bound is substantially weakened and can even disappear so that the constraints on the higgs and stop masses do not apply anymore. Such modification of cosmology at early times therefore reopens the parameter space allowing electroweak baryogenesis which had been reduced substantially given the new bound on the higgs mass imposed by LEP. In contrast with previous attempts to turn around the sphaleron bound using alternative cosmologies, we are still considering that the electroweak phase transition takes place in a radiation dominated universe. The universe is expanding fast because of the modification of the Friedmann equation itself without the need for a scalar field and therefore evading the problem of the decay of this scalar field after the completion of the phase transition and the risk that its release of entropy dilutes the baryon asymmetry produced at the transition.Comment: 19 pages, 3 figures; v2: minor changes, remark added at end of section 5 and in caption of figure 1; v3: references added, version to be publishe

Strong constraint on large extra dimensions from cosmology

We have studied cosmological constraints on the number and radii of possible large extra dimensions. If such dimensions exist, Kaluza-Klein (KK) modes are copiously produced at high temperatures in the early universe, and can potentially lead to unacceptable cosmological effects. We show that during reheating, large numbers of KK modes are produced. These modes are not diluted completely by the entropy production during reheating because they are produced non-relativistically. This means that the modes produced during reheating can easily be the dominant component. For instance, for two extra dimensions the bound on their radii from considering only the thermally produced KK modes is R < 1.1 x 10^-4 mm. If the modes produced during reheating are also accounted for, the bound is strengthened to R < 2.2 x 10^-5 mm. This bound is stronger than all other known astrophysical or laboratory limits.Comment: 6 pages, 3 figures, matches version to appear in Phys Rev

Experimental Probes of the Randall-Sundrum Infinite Extra Dimension

The phenomenological possibilities of the Randall-Sundrum non-compact extra dimension scenario with the AdS horizon increased to approximately a millimeter length, corresponding to an effective brane tension of TeV^4, are investigated. The corrections to the Newtonian potential are found to be the only observationally accessible probe of this scenario, as previously suggested in the literature. In particular, the presence of the continuum of KK modes does not lead to any observable collider signatures. The extent to which experimental tests of Newtonian gravity can distinguish this scenario from the scenario of Arkani-Hamed, Dimopoulos, and Dvali with one and two millimeter size extra dimensions is explicitly demonstrated.Comment: 22 pages, 2 figures, references adde

A DSEL for Studying and Explaining Causation

We present a domain-specific embedded language (DSEL) in Haskell that supports the philosophical study and practical explanation of causation. The language provides constructs for modeling situations comprised of events and functions for reliably determining the complex causal relationships that emerge between these events. It enables the creation of visual explanations of these causal relationships and a means to systematically generate alternative, related scenarios, along with corresponding outcomes and causes. The DSEL is based on neuron diagrams, a visual notation that is well established in practice and has been successfully employed for causation explanation and research. In addition to its immediate applicability by users of neuron diagrams, the DSEL is extensible, allowing causation experts to extend the notation to introduce special-purpose causation constructs. The DSEL also extends the notation of neuron diagrams to operate over non-boolean values, improving its expressiveness and offering new possibilities for causation research and its applications.Comment: In Proceedings DSL 2011, arXiv:1109.032