Does The Story Of The Destruction Of The City of Sodom Reflect A Meteor Strike?

There are really three pieces of this hypothesis. One is the identification of Tall el-Hammam in the modern country of Jordon with the Biblical city of Sodom. The second is whether there are indications of a meteor strike there in a Bronze Age or Iron Age time frame when a city existed there. While not irrefutable, the hypothesis seems plausible. I will try to track down a journal article on the hypothesis at some point.

In November 2018, Phillip Silvia, Ph.D of Trinity Southwest University in New Mexico, made a presentation to the American Schools of Oriental Research in which he put forth the theory that the ancient city of Sodom was destroyed by a giant meteor. . . . In Genesis 19, God sends his angels to destroy the city. . . . He posits that a meteor exploded in the air above the Middle East and created a circle-shaped plain on the northeastern edge of the Dead Sea, an area called Middle Ghor, in today’s Jordan. 

According to Silvia, the area of Middle Ghor had been settled for about 2,500 years before the Bronze Age (2000-500 BC). Excavations carried out in the area at five different sites illustrate this. Another further 120 sites have been surveyed in the area. He and others of his team believe that the Middle Ghor region was the home of the ancient city (or city-state) of Sodom. 

The most telling archaeological feature of the area are the ruins of the city of Tall el-Hammam. Silvia and colleagues led by Dr. Steven Collins, have been excavating the site for 13 years, and what they have found, they say, indicates evidence of a gigantic low-altitude airburst meteor of the Chelyabinsk/Tunguska type. 

As evidence that the site was Sodom, they say they have found pottery shards depicting sexual relations between men and boys. Tall el-Hammam is also the largest city of the region, and in the Bible, Sodom is one of the “cities of the plain” mentioned by name. 

. . . 

Tall el-Hammam covers one hundred acres. Jericho covered ten. Ancient Jerusalem ten as well. The Bible says that Sodom had a large defensive wall, and Tall el-Hammam has one made up of an estimated 60-90 million bricks: eight meters thick at the top, forty at the bottom. 

Geological descriptions and words found in the Bible match Tall el-Hammam. The location was abandoned for about 700 years, in the middle of one of the centers of world civilization at the time, and a fertile one, at that. This suggests, says Silvia and his colleagues, that people were sufficiently awed by what happened that they stayed away for centuries. 

What could have awed them, and what could have turned (as the Bible says), Lot’s wife into a “pillar of salt,” and caused a flaming vortex such as that mentioned in Genesis 19? A huge meteor. 

The pottery mentioned above? The outer parts are turned into glass. The rock walls disappeared suddenly 3,700 years ago, according to carbon dating of their foundations, the only parts left. Lot’s family would have made their way along the shore of the Dead Sea, one of the saltiest bodies of water in the world. 

They were under instructions from God’s angels not to look back at the city unless they wanted to be turned into “pillars of salt.” 

Should Lot’s wife have had second thoughts, or should her “look back” have amounted to more than just a peek (perhaps a long stop to make sure she was making the right decision, looking back to get one more glimpse of home for her memory, or just out of curiosity), and if that is the case and the meteor exploded over the Dead Sea, she might indeed have been covered in boiling salt water, or gas. 

If some of the sea breached its shores as a result of the explosion, salt would have covered the entire landscape – making it uninhabitable. 

Further scientific research indicates that the topsoil near Tall el-Hammam shows that the topsoil of the time was severely disrupted and that the subsoil revealed below was contaminated with salt, making the land decidedly sterile. This could have been another reason people stayed away for so long.

From here.

South American Genetics

Was Amazonian agriculture a local innovation or transmitted by early Neolithic cultures of the Americas? Is there population genetic structure corresponding to mtDNA patterns showing a more or less exclusively Pacific coastal clade? This and some other recent studies is also starting to show the interplay of prehistoric civilizations in the Americas.

Studies of Native South American genetic diversity have helped to shed light on the peopling and differentiation of the continent, but available data are sparse for the major ecogeographic domains. These include the Pacific Coast, a potential early migration route; the Andes, home to the most expansive complex societies and to one of the most spoken indigenous language families of the continent (Quechua); and Amazonia, with its understudied population structure and rich cultural diversity. Here we explore the genetic structure of 177 individuals from these three domains, genotyped with the Affymetrix Human Origins array. We infer multiple sources of ancestry within the Native American ancestry component; one with clear predominance on the Coast and in the Andes, and at least two distinct substrates in neighboring Amazonia, with a previously undetected ancestry characteristic of northern Ecuador and Colombia. Amazonian populations are also involved in recent gene-flow with each other and across ecogeographic domains, which does not accord with the traditional view of small, isolated groups. Long distance genetic connections between speakers of the same language family suggest that languages had spread not by cultural contact alone. Finally, Native American populations admixed with post-Columbian European and African sources at different times, with few cases of prolonged isolation. With our results we emphasize the importance of including under-studied regions of the continent in high-resolution genetic studies, and we illustrate the potential of SNP chip arrays for informative regional scale analysis.

Chiara Barbier, et al., "The genomic landscape of western South America: Andes, Amazonia and Pacific Coast" bioRxiv (December 23, 2018).

From the Introduction:

In South America, genetic studies robustly recovered a substantial differentiation between the Andes and Amazonia, which has been framed within a model of large communities connected by gene-flow in the Andes vs. small, isolated communities in Amazonia. This model builds on evidence for major complex societies in the Andes (culminating with the well-known but short-lived Inca empire) which fostered population movements and connections, counterbalanced by the traditional view of the Amazon basin as the homeland of small, isolated tribes. The latter view is challenged by increasing evidence of large-scale societies, the role of rivers as primary routes for gene-flow, and the presence of important centers of plant domestication. To gain a better representation of the highly diverse cultural landscape of Amazonia, a more intense archaeological effort is needed, together with a more fine-grained sampling of living and ancient human populations. 

In particular, this model of South American genetic structure typically overlooks the Pacific Coast, a key context for the early migration history of the continent and the cradle of the earliest complex societies in South America, from 3000 BCE. Recent studies have begun to investigate human variation on the Pacific coast through aDNA and by sampling urban areas, but to fill out this picture requires further, complementary genetic studies on living populations (especially from non-urban areas).

Language diversity can also be a factor shaping population relatedness. The diffusion of major language families is traditionally associated with demographic movements: this association was validated with genetic data for some of the largest language families of the world, but no strong candidates are found in South America, where genetic diversity overall does not correlated with linguistic diversity. Previous genetic work evaluated alternative models of cultural vs. demographic diffusion for Quechua, the most spoken language family of the Andes, present also in small pockets of the Amazonian lowlands. These studies, based on uniparental markers, revealed intense contact routes in the southern highlands, but not in the northern regions nor in neighboring Amazonia. Relatively few genetic studies have addressed the diffusion of the main language families of Amazonia (notably Arawak, Tupí or Carib), although very recent research does focus on sub-branches or smaller families. Some scholars suggest a major role for cultural contact alone behind the diffusion of Arawak. The particularly fragmented distribution of the three major language families across much of lowland South America calls for a more fine-grained sampling to test for potential connections between their speaker populations. 

Here we focus on western South America to investigate environmental and cultural influences on population genetic structure over the three ecogeographic domains: the Andes, the Amazonia and the Pacific Coast, and transitional environments in between. The analysis of new genetic samples from populations with different cultural, linguistic and historical backgrounds should contribute to understanding both the modes of early migration and the immediate consequences of colonial contact. A first open question concerns the scale of the genetic impact of major complex societies, which arose in two main focal regions: the north coast of Peru, and the Andean highlands of Central and Southern Peru and northern Bolivia. Large-scale societies possibly left a trace in the demographic profiles of indigenous populations, associated with high population density, but the extent of long-distance population movements and the origins of the populations that developed such societies remain largely unknown. A second open question concerns the diffusion mechanisms of major language families. We aim at tracing genetic connections over the scattered and widespread diffusion of representative Andean and Amazonian languages, focusing in particular on a vast region where different varieties of Quechua are spoken. Finally, a third open question concerns the demographic events occurring over the last five centuries since European contact, and how they impacted upon different South American populations. Gene flow from European and African sources can be easily distinguished in the genomic ancestry of the American populations. The timing and intensity of the European-mediated admixture has been estimated for urban, heavily admixed regions, but has yet to be investigated systematically across South America.

From the discussion section:

[W]e investigated Native American ancestry across the continent. One major Native American ancestry component is shared by all populations, as seen in the ADMIXTURE plot (Fig. S2, K=3, associated with the lowest Cross Validation error), in line with results from other living populations and from ancient DNA, which support a single major migration . This Native American component exhibits a marked population structure; the main signal of structure separates Amazonia from a shared Andes/Coast ancestry. Populations from North America were shown to have a distinct ancestry component in the ADMIXTURE analysis (Fig. S2), with a smaller differentiation between populations from southern North America (Yaquis and Pima) and Meso-/Central America (Mixe and Cabecar, Fig. S4). The diversification of these ancestry blocks from the initial single Native American gene pool does not bear traces of a north-south gradient of differentiation, or of serial founder effects, as the genetic distances between populations displays a radial structure rather than a sequential one (Fig. S4). A previously observed early diverging component similar to the Mixe or the ancient Californian Channel Islands is not captured by our data, which focuses more on South American genetic diversity. Amazonian ancestry is further split into two components: one more widespread in the Amazon Basin (here called “Amazonian Core”), the other corresponding to the piedmont populations of Ecuador and south-western Colombia (“Amazonian North”, Fig. 1 and 2). This latter component is strongly differentiated (it is one of the first ancestry components to appear in the ADMIXTURE analysis, at K=4 - Fig. S2), suggesting that it either diverged early in the migration process, or reflects stronger drift than in the rest of Amazonia. It is unclear if this ancestry could correspond to one branch of the earliest continental population structure, which were hypothesized from aDNA admixture graph reconstructions. This “Amazonian North” ancestry represents a previously unreported source of ancestry from a transitional environment: this region is in fact geographically close to the Northern Andes between Colombia and Ecuador, but its populations are traditionally associated with the Amazonian cultural domain. An early human settlement of Ecuador and northern Peru (between 16.0 and 14.6 kya) has previously been inferred from high resolution mtDNA data, in line with the archaeological record. Meanwhile, the presence of pockets of diversity in Ecuador and Colombia is paralleled by the presence of distinctive Native American lineages, such as Y chromosome haplogroup C3, otherwise rare in the continent. This haplogroup is also reported for other populations in Colombia. Interestingly, haplogroup C is found in the sample from Ecuador (Fig. S8, Table S1), too, but further analysis is needed to precisely identify the Y chromosome subhaplogroup and confirm the C3 affiliation. Finally, populations from the Coast and the Central Andes (both north and south) show close genetic proximity to each other, as visualized by the PCA in Fig.s 2A and 2B and by the same ancestry component profile up until K=6 in Fig. S2). This strongly suggests a common origin and/or extensive contact, which may be associated with a coastal migration route and a colonization process from the coast inland into the highlands. Previous analyses have already noted the common history of these two regions, with first settlement from around 12,000 years ago. . . . 

[W]e explored signatures of demographic history and haplotype sharing patterns. The ROH variation profile of most populations from the Coast and the Andes (both North-East and Central-Southern) is consistent with a history of a relatively large population size, with some exceptions (Sechura, Narihuala, Cusco) that may have experienced isolation and drift only very recently (Fig. 3, Fig. S5). The long-term presence of large-scale state societies in the Andes and on the Coast can be expected to have promoted gene flow across wider geographical scales and merged previously structured populations, contributing to the higher genetic diversity of the current inhabitants. On the north coast of Peru, the Moche culture was one of the largest entities from the 1st century CE, followed by the Chimú from the 12th century. Their political influence over the coast would have promoted human connections that overcame the long stretches of desert that separate the main river valleys and the Humboldt current and wind regime that make long-distance seaborne trade difficult. In the Chachapoyas region (North-East Andes), a number of structured societies flourished from the 12th to the 15th century. In the Central-Southern Andes, the Wari and Tiahuanaco ‘Middle Horizon’ (c. 500-1000 CE) and especially the Inca ‘Late Horizon’ (c. 1470-1532 CE) established vast networks that mobilized and moved large labor forces for agricultural production (terracing, irrigation, raised fields), operated resource exchanges through camelid caravans, and resettled populations as explicit state policy. The impact of the Wari and Inca Empires is widely associated also with the diffusion of the two main surviving Andean language families, Quechua and Aymara. 

There is some genetic linkage with language families.

The Coast and our two Andean sub-regions share a similar ancestry (as discussed above) and a similar history of large population size, but they are differentiated at a finer scale, with localized patterns of IBD segment sharing. Longer IBD blocks are shared almost exclusively within each of the three geographic macro-regions: Coast, North-East Andes and Central-Southern Andes, with the latter sharing fewer and shorter segments, suggesting more ancient contact over a large region, not sustained until recent times (Fig. 4). By contrast, the Amazonian populations in most cases have longer ROH blocks and overall high levels of consanguinity. This could reflect the model first proposed by: larger groups in the Andes vs. small, isolated groups in Amazonia. Nevertheless, by including more populations from a wider range of cultural and geographical backgrounds, we find exceptions to this model with some Amazonian populations characterized by a smaller number of larger blocks, belonging to group 1c and group 2 in Fig. S5. The populations of Amazonia therefore display different demographic histories rather than a uniform history of small sample size (according to the ROH profiles) and are connected by sharing of IBD blocks within the region. Moreover, Amazonian populations also show long distance sharing of large and short fragments with the Andes and the Coast (Fig. 4), which is not consistent with the traditional portrait of isolation between Amazonian populations. This genetic diversity complements the evidence from other disciplines that the region was also home to dynamic, non-isolated population groups. In particular, the linguistic diversity of Amazonia includes not just language isolates but major, expansive language families, with far reaching geographic distributions, reflecting long-range migrations of at least some speakers, and possibly major demographic expansions. There is also clear linguistic evidence for intensive interactions in convergence zones, and (more weakly) across Amazonia as a whole. We explored these potential connections by checking for gene-flow among speakers of the same language or language family. An interesting case is represented by the speakers of Cocama, a language of the Tupí family. The ROH profile for the Cocama of Colombia is lacking in long ROH segments (Fig. 3, Fig. S5), suggesting no recent bottlenecks or isolation. The analysis of shared IBD segments, which indicate shared ancestry through recent contact, reveals a long distance connection between this population and geographically-distant populations of Peruvian Amazonia (Fig. 4). In particular, three Cocama speakers included in the LoretoMix sample from Peru are slightly different from the rest of the LoretoMix sample, and genetically closer to the Cocama of Colombia (Fig. 2A). Archaeological and ethnohistorical evidence indicates that the ancestors of the Cocama and Omagua were widespread in pre-Columbian times, inhabiting large stretches of the Amazon Basin and several of its upper tributaries. Thus, the sharing of IBD segments as well as the lack of long ROH in the Cocama could be explained by large, widespread populations that were connected in pre-Columbian times. Alternatively, more recent migrations could have carried the Cocama language between Colombia and Peru. Both time–frames and both scenarios suggest a parallel between genetic and linguistic history, with language acting as a preferential vector of population mobility. 

There is evidence of patrilocality and bride exchange over substantial distances.

Weak evidence for long-distance linguistic connections is observed not only within Amazonia, but also between Amazonia and the Andes. This is the case for Quechua-speakers of lowland Ecuador (Kichwa Orellana) and lowland north-eastern Peru (Wayku), who share relatively short IBD fragments with Central-Southern Andes and North-East Andes respectively. Previous results based on Y chromosome haplotype sharing did find a similar pattern of connections between lowland Quechua-speakers in Ecuador and north-eastern Peru, but did not find such long-distance connections with the Central and Southern Andes. These different results can possibly be justified by sex-biased gene-flow (i.e. less male mobility), which should be further investigated with denser sampling and high-resolution mtDNA genome sequences. Overall, this new genomic evidence points towards a demographic connection behind the diffusion of Quechua varieties not only in the southern highlands, as previously attested, but also in the north, across ecogeographic domains. The genetic signature reconstructed can inform the historical reconstructions for the diffusion of this language family.

Archaeologists Find Oldest Aramaic Inscription

Archaeologists found a vessel in what is now Turkey, which dates from 850 BCE to 800 BCE and contains is the oldest Aramaic inscription ever found, setting forth a magical incantation.

Written by a man who practiced magic who is called "Rahim son of Shadadan," the incantation"describes the seizure of a threatening creature [called] the 'devourer,'" wrote Madadh Richey and Dennis Pardee in the abstract of a presentation they gave recently at the Society of Biblical Literature annual meeting. That event took place in Denver between Nov 17 and 21. The blood of the devourer was used to treat someone who appears to have been suffering from the "fire" of the devourer[.]

The structure in which it was found was at least a hundred years older than the inscription, indicating its importance to the people who lived there. 

Contrarian Astronomy Results

One recent paper makes the case that one fairly small spiral galaxy has considerable unaccounted for apparent mass in its central region, contrary to the predictions of MOND in a system well within its range of applicability and also demonstrating an unusual cuspy dark matter profile in a Cold Dark Matter paradigm, unlike most observed galaxies, despite the fact that the NFW dark matter halo distribution which an analytical treatment of collisionless CDM should produce.

It isn't at all clear why this galaxy is an outlier.

(I am short for time today, so I will cut corners in presenting the underlying paper and abstracts.)

Dark Matter in the Central Region of the Spiral Galaxy NGC 4321

Israa Abdulqasim Mohammed Ali, Chorng-Yuan Hwang, Zamri Zainal Abidin

(Submitted on 13 Dec 2018)

We present our results of 12 CO(1-0) transition in the central region of NGC 4321 using the Atacama Large Millimeter and Sub-millimeter Array (ALMA). We found an unaccounted mass of 2.3×109M⊙ within the central 0.7 kpc of this galaxy. The expected mass of the supermassive black hole (SMBH) in this galaxy is much smaller than the unaccounted mass. The invisible mass is likely caused by dark matter in the central region of the galaxy, indicating a cuspy dark matter profile. We also investigated the Modified Newtonian Dynamics (MOND) as an alternative mechanism to explain the invisible mass. We noted that at the radius of 0.7 kpc of the galaxy, the acceleration is about 1.04×10−7 cm s−2, which is much larger than the critical acceleration a0∼1.2×10−8 cm s−2 in the MOND theory, suggesting that theory might not be able explain the unseen mass problem in central region of this galaxy.

Another new paper seeks to explain the discrepancies between two different Hubble constant measurements by different methods by assuming contrary to the Plank experiment's conclusions, that there are four, rather than three kinds of neutrinos. The Plank experiment has favored three neutrino types (which implies a 3.045 effective number of neutrino types, Neff) on a 5 sigma basis, which turns out to be model dependent, while the contrarian view interpreting the data with a different model, favors four neutrino types over three on a 3 sigma basis. The stark contrast from more or less the same input data, demonstrates well the limits of statistical significance in the face of large theoretical uncertainties.

Is the H0 tension suggesting a 4th neutrino's generation?

S. Carneiro, P. C. de Holanda, C. Pigozzo, F. Sobreira

(Submitted on 14 Dec 2018)

Flavour oscillations experiments are suggesting the existence of a sterile, 4th neutrino's generation with a mass of an eV order. This would mean an additional relativistic degree of freedom in the cosmic inventory, in contradiction with recent results from the Planck satellite, that have confirmed the standard value Neff≈3 for the effective number of relativistic species. On the other hand, the Planck best-fit for the Hubble-Lemaître parameter is in tension with the local value determined with the Hubble Space Telescope, and adjusting Neff is a possible way to overcome such a tension. In this paper we perform a joint analysis of three complementary cosmological distance rulers, namely the CMB acoustic scale measured by Planck, the BAO scale model-independently determined by Verde {\it et al.}, and luminosity distances measured with JLA and Pantheon SNe Ia surveys. Two Gaussian priors were imposed to the analysis, the local expansion rate measured by Riess {\it et al.}, and the baryon density parameter fixed from primordial nucleosynthesis by Cooke {\it et al.}. For the sake of generality, two different models are used in the tests, the standard ΛCDM model and a generalised Chaplygin gas. The best-fit gives Neff≈4 in both models, with a Chaplygin gas parameter slightly negative, α≈−0.04. The standard value Neff≈3 is ruled out with ≈3σ.

Two other recent papers also consider Neff. One does so in the context of lepton number asymmetry and also seeks to resolve the tension in the measurements of the Hubble constant.

Lepton Number and Expansion of the Universe

Cheng Tao Yang, Jeremiah Birrell, Johann Rafelski

(Submitted on 12 Dec 2018)

We show that the non-integer effective number of neutrinos Neffν can be understood as an effect of lepton L asymmetry in the early Universe carried by the Dirac neutrino cosmic background. We show that Neffν=3.36±0.34 (CMB only) and Neffν=3.62±0.25 (CMB and H0) require a ratio between baryon number B and lepton number to be 1.16×10−9⩽B/|L|⩽1.51×10−9. These values are close to the baryon-to-photon ratio 0.57×10−9⩽B/Nγ⩽0.67×10−9. Thus instead of the usual |L|≪Nγ and B≃|L|, we propose to use 0.4⩽|L|/Nγ⩽0.52 and B≪|L| as another natural choice, which resolves the tension between Planck-CMB and H0 and leads to a non-integer value of Neffν>3.

The other tries to link the dark matter aspects of the Concordance Cosmology model use MeV (lukewarm dark matter?) mass dark matter particles with the effective neutrino number.

Neutrino Decoupling Beyond the Standard Model: CMB constraints on the Dark Matter mass with a fast and precise Neff evaluation

Miguel Escudero

(Submitted on 13 Dec 2018)

The number of effective relativistic neutrino species represents a fundamental probe of the thermal history of the early Universe, and as such of the Standard Model of Particle Physics. Traditional approaches to the neutrino decoupling are either very technical and computationally expensive, or assume that neutrinos decouple instantaneously. In this work, we aim to fill the gap between these two approaches by modelling the neutrino decoupling in terms of two simple coupled differential equations for the electromagnetic and neutrino sector temperatures, in which all the relevant interactions are taken into account and which allows for a straightforward implementation of BSM species. Upon including finite temperature QED corrections we reach an accuracy on Neff in the SM of 0.01. We illustrate the usefulness of this approach to the neutrino decoupling by considering, in a model independent manner, the impact of MeV thermal dark matter on Neff. We show that Planck rules out electrophilic and neutrinophilic thermal dark matter particles of m<4.4MeVregardless of their spin, and of their annihilation being s-wave or p-wave. We point out that thermal dark matter particles with non-negligible interactions with both electrons and neutrinos are more elusive to CMB observations than purely electrophilic or neutrinophilic ones. In addition, assisted by the accuracy of our approach, we show that CMB Stage-IV experiments will generically test thermal dark matter particles with m≲20MeV. We make publicly available the codes developed for this study at this https URL. 

Finally, a new paper rehashes the warm dark matter paradigm considering self-interacting MeV dark matter particles (lukewarm dark matter?), and finds that the results don't differ greatly from keV mass particle warm dark matter models.

KeV Scale Frozen-in Self-Interacting Fermionic Dark Matter

Haipeng An, Ran Huo, Wanqiang Liu

(Submitted on 13 Dec 2018)

We present a model in which the dark matter particle is frozen-in at MeV scale. In this model, the mediator between the standard model sector and the dark sector can automatically provide a self-interaction for dark matter. The interaction strength is naturally to be the in the region in favor of the cluster mass deficit anomaly. Due to the self-scattering, the Lyman-α constraint can be relaxed to mD≳2 keV. In this region the self-interaction and the Fermi pressure both play roles on forming a dark matter core at the center of the dwarf galaxies.

Yet another new paper evaluates how gravity wave telescope may make it possible to evaluate the "no hair theorem" about black holes observationally.

Hair loss in parity violating gravity

Pratik Wagle, Nicolas Yunes, David Garfinkle, Lydia Bieri

(Submitted on 13 Dec 2018)

The recent detection of gravitational waves by the LIGO/VIRGO collaboration has allowed for the first tests of Einstein's theory in the extreme gravity regime, where the gravitational interaction is simultaneously strong, non-linear and dynamical. One such test concerns the rate at which the binaries inspiral, or equivalently the rate at which the gravitational wave frequency increases, which can constrain the existence of hairy black holes. This is because black holes with scalar hair typically excite dipole radiation, which in turn leads to a faster decay rate and frequency chirping. In this paper, we present a mathematical proof that scalar hair is not sourced in vacuum, spherically symmetric spacetimes when considering extensions of Einstein's theory that break parity in gravity, focusing on dynamical Chern-Simons theory as a particular toy model. This result implies that the observational confirmation of the baldness of black holes cannot be used to constrain parity violation in gravity, unless the black holes observed are also spinning.

In other physics news, there is a new paper from ATLAS and CMS combined regarding the top quark's properties.

Top quark properties

Petra Van Mulders (on behalf of the ATLAS and CMS Collaborations)

(Submitted on 14 Dec 2018)

The multi-purpose experiments at CERN's Large Hadron Collider have a very rich programme in top quark physics. The large amount of data allows for measuring the top quark properties with an unprecedented precision. This document presents some of the properties that have been measured using top quark pair events produced in proton-proton collisions with a centre-of-mass energy of 13 TeV. The focus lies on the measurements of the colour flow, the charge asymmetry and spin correlations in top quark pair events.

A counterpart to the W boson that interacts only with right handed parity particles rather than left handed ones like the ordinary W boson is excluded experimentally up to masses of more than 3 TeV.

Relaxing LHC constraints on the WR mass

Mariana Frank, Özer Özdal, Poulose Poulose

(Submitted on 13 Dec 2018)

We study mass bounds of the WR gauge boson in generic left-right symmetric models. Assuming that the gauge bosons couple universally to quarks and leptons, we allow different gauge couplings gR≠gL and mass mixing, VLCKM≠VRCKM in the left and right sectors. Imposing constraints from collider experiments and K0, Bd, Bs physics, we investigate scenarios where WR is lighter, or heavier than the right handed neutrino νR. In these scenarios, WRmass bounds can be considerably relaxed, while ZR mass bounds are much more stringent. In the case where MWR≤MνR, the experimental constraints come from WR→tb and WR→jj channels, while if MWR≥MνR, the dominant constraints come from WR→ℓℓjj. The observed (expected) limits in the two-dimensional (MWR, MνR) mass plane excluded at 95\% confidence level extend to approximately MWR= 3.1 (3.3) TeV in the ee channel and 3.3 (3.4) TeV in the (μμ) channel, for a large range of right-handed neutrino masses up to MνR= 2.1 (2.1) TeV in the ee channel and 2.6 (2.5) in the (μμ) channel, representing a significant relaxation of the mass bounds.