pinecone/core-2020-05-10-deduplication huggingface dataset:
Top Condensation as a Motivated Explanation of the Top Forward-Backward Asymmetry

Models of top condensation can provide both a compelling solution to the hierarchy problem as well as an explanation of why the top-quark mass is large. The spectrum of such models, in particular topcolor-assisted technicolor, includes top-pions, top-rhos and the top-Higgs, all of which can easily have large top-charm or top-up couplings. Large top-up couplings in particular would lead to a top forward-backward asymmetry through t-channel exchange, easily consistent with the Tevatron measurements. Intriguingly, there is destructive interference between the top-mesons and the standard model which conspire to make the overall top pair production rate consistent with the standard model. The rate for same-sign top production is also small due to destructive interference between the neutral top-pion and the top-Higgs. Flavor physics is under control because new physics is mostly confined to the top quark. In this way, top condensation can explain the asymmetry and be consistent with all experimental bounds. There are many additional signatures of topcolor with large tu mixing, such as top(s) + jet(s) events, in which a top and a jet reconstruct a resonance mass, which make these models easily testable at the LHC.Physic
Universal Constraints on Low-Energy Flavour Models

It is pointed out that in a general class of flavour models one can identify
certain universally present FCNC operators, induced by the exchange of heavy
flavour messengers. Their coefficients depend on the rotation angles that
connect flavour and fermion mass basis. The lower bounds on the messenger scale
are derived using updated experimental constraints on the FCNC operators. The
obtained bounds are different for different operators and in addition they
depend on the chosen set of rotations. Given the sensitivity expected in the
forthcoming experiments, the present analysis suggests interesting room for
discovering new physics. As the highlights emerge the leptonic processes,
$\mu\rightarrow e\gamma$, $\mu\rightarrow eee$ and $\mu\rightarrow e$
conversion in nuclei.Comment: 18 pages, 3 figures; v2 matches published versio
Locality in Theory Space

Locality is a guiding principle for constructing realistic quantum field
theories. Compactified theories offer an interesting context in which to think
about locality, since interactions can be nonlocal in the compact directions
while still being local in the extended ones. In this paper, we study locality
in "theory space", four-dimensional Lagrangians which are dimensional
deconstructions of five-dimensional Yang-Mills. In explicit ultraviolet (UV)
completions, one can understand the origin of theory space locality by the
irrelevance of nonlocal operators. From an infrared (IR) point of view, though,
theory space locality does not appear to be a special property, since the
lowest-lying Kaluza-Klein (KK) modes are simply described by a gauged nonlinear
sigma model, and locality imposes seemingly arbitrary constraints on the KK
spectrum and interactions. We argue that these constraints are nevertheless
important from an IR perspective, since they affect the four-dimensional cutoff
of the theory where high energy scattering hits strong coupling. Intriguingly,
we find that maximizing this cutoff scale implies five-dimensional locality. In
this way, theory space locality is correlated with weak coupling in the IR,
independent of UV considerations. We briefly comment on other scenarios where
maximizing the cutoff scale yields interesting physics, including theory space
descriptions of QCD and deconstructions of anti-de Sitter space.Comment: 40 pages, 11 figures; v2: references and clarifications added; v3:
  version accepted by JHE
Supersymmetry Breaking in Chern-Simons-matter Theories

Some of supersymmetric Chern-Simons theories are known to exhibit
supersymmetry breaking when the Chern-Simons level is less than a certain
number. The mechanism of the supersymmetry breaking is, however, not clear from
the field theory viewpoint. In this paper, we discuss vacuum states of ${\cal
N}=2$ pure Chern-Simons theory and ${\cal N}=2$ Chern-Simons-matter theories of
quiver type using related theories in which Chern-Simons terms are replaced
with (anti-)fundamental chiral multiplets. In the latter theories,
supersymmetry breaking can be shown to occur by examining that the vacuum
energy is non-zero.Comment: 17 pages, 3 figures, v2) references adde
Revisiting Scalar and Pseudoscalar Couplings with Nucleons

Certain dark matter interactions with nuclei are mediated possibly by a
scalar or pseudoscalar Higgs boson. The estimation of the corresponding cross
sections requires a correct evaluation of the couplings between the scalar or
pseudoscalar Higgs boson and the nucleons. Progress has been made in two
aspects relevant to this study in the past few years. First, recent lattice
calculations show that the strange-quark sigma term $\sigma_s$ and the
strange-quark content in the nucleon are much smaller than what are expected
previously. Second, lattice and model analyses imply sizable SU(3) breaking
effects in the determination on the axial-vector coupling constant $g_A^8$ that
in turn affect the extraction of the isosinglet coupling $g_A^0$ and the
strange quark spin component $\Delta s$ from polarized deep inelastic
scattering experiments. Based on these new developments, we re-evaluate the
relevant nucleon matrix elements and compute the scalar and pseudoscalar
couplings of the proton and neutron. We also find that the strange quark
contribution in both types of couplings is smaller than previously thought.Comment: 17 pages, Sec. II is revised and the pion-nucleon sigma term
  extracted from the scattering data is discussed. Version to appear in JHE
M-brane Models from Non-Abelian Gerbes

We make the observation that M-brane models defined in terms of 3-algebras
can be interpreted as higher gauge theories involving Lie 2-groups. Such gauge
theories arise in particular in the description of non-abelian gerbes. This
observation allows us to put M2- and M5-brane models on equal footing, at least
as far as the gauge structure is concerned. Furthermore, it provides a useful
framework for various generalizations; in particular, it leads to a fully
supersymmetric generalization of a previously proposed set of tensor multiplet
equations.Comment: 17 pages, v2: new SUSY models, version published in JHE
Composite Scalar Dark Matter

We show that the dark matter (DM) could be a light composite scalar $\eta$,
emerging from a TeV-scale strongly-coupled sector as a pseudo Nambu-Goldstone
boson (pNGB). Such state arises naturally in scenarios where the Higgs is also
a composite pNGB, as in $O(6)/O(5)$ models, which are particularly predictive,
since the low-energy interactions of $\eta$ are determined by symmetry
considerations. We identify the region of parameters where $\eta$ has the
required DM relic density, satisfying at the same time the constraints from
Higgs searches at the LHC, as well as DM direct searches. Compositeness, in
addition to justify the lightness of the scalars, can enhance the DM scattering
rates and lead to an excellent discovery prospect for the near future. For a
Higgs mass $m_h\simeq 125$ GeV and a pNGB characteristic scale $f \lesssim 1$
TeV, we find that the DM mass is either $m_\eta \simeq 50-70$ GeV, with DM
annihilations driven by the Higgs resonance, or in the range 100-500 GeV, where
the DM derivative interaction with the Higgs becomes dominant. In the former
case the invisible Higgs decay to two DM particles could weaken the LHC Higgs
signal.Comment: 19 pages + appendices, 16 figures. v2: minor changes. v3: version
  published in JHE
Numerical Algebraic Geometry: A New Perspective on String and Gauge
  Theories

The interplay rich between algebraic geometry and string and gauge theories
has recently been immensely aided by advances in computational algebra.
However, these symbolic (Gr\"{o}bner) methods are severely limited by
algorithmic issues such as exponential space complexity and being highly
sequential. In this paper, we introduce a novel paradigm of numerical algebraic
geometry which in a plethora of situations overcomes these short-comings. Its
so-called 'embarrassing parallelizability' allows us to solve many problems and
extract physical information which elude the symbolic methods. We describe the
method and then use it to solve various problems arising from physics which
could not be otherwise solved.Comment: 36 page
Hadronic Contributions to the Muon Anomaly in the Constituent Chiral
  Quark Model

The hadronic contributions to the anomalous magnetic moment of the muon which
are relevant for the confrontation between theory and experiment at the present
level of accuracy, are evaluated within the same framework: the constituent
chiral quark model. This includes the contributions from the dominant hadronic
vacuum polarization as well as from the next--to--leading order hadronic vacuum
polarization, the contributions from the hadronic light-by-light scattering,
and the contributions from the electroweak hadronic $Z\gamma\gamma$ vertex.
They are all evaluated as a function of only one free parameter: the
constituent quark mass. We also comment on the comparison between our results
and other phenomenological evaluations.Comment: Several misprints corrected and a clarifying sentence added. Three
  figures superposed and two references added. Version to appear in JHE
b-Initiated processes at the LHC: a reappraisal

Several key processes at the LHC in the standard model and beyond that
involve $b$ quarks, such as single-top, Higgs, and weak vector boson associated
production, can be described in QCD either in a 4-flavor or 5-flavor scheme. In
the former, $b$ quarks appear only in the final state and are typically
considered massive. In 5-flavor schemes, calculations include $b$ quarks in the
initial state, are simpler and allow the resummation of possibly large initial
state logarithms of the type $\log \frac{{\cal Q}^2}{m_b^2}$ into the $b$
parton distribution function (PDF), ${\cal Q}$ being the typical scale of the
hard process. In this work we critically reconsider the rationale for using
5-flavor improved schemes at the LHC. Our motivation stems from the observation
that the effects of initial state logs are rarely very large in hadron
collisions: 4-flavor computations are pertubatively well behaved and a
substantial agreement between predictions in the two schemes is found. We
identify two distinct reasons that explain this behaviour, i.e., the
resummation of the initial state logarithms into the $b$-PDF is relevant only
at large Bjorken $x$ and the possibly large ratios ${\cal Q}^2/m_b^2$'s are
always accompanied by universal phase space suppression factors. Our study
paves the way to using both schemes for the same process so to exploit their
complementary advantages for different observables, such as employing a
5-flavor scheme to accurately predict the total cross section at NNLO and the
corresponding 4-flavor computation at NLO for fully exclusive studies.Comment: Fixed typo in Eq. (A.10) and few typos in Eq. (C.2) and (C.3
Coupling dependence of jet quenching in hot strongly-coupled gauge
  theories

Previous top-down studies of jet stopping in strongly-coupled QCD-like
plasmas with gravity duals have been in the infinite 't Hooft coupling limit
lambda -> infinity. They have found that, though a wide range of jet stopping
distances are possible depending on initial conditions, the maximum jet
stopping distance l_max scales with energy as E^(1/3) at large energy. But it
has always been unclear whether the large-coupling and high-energy limits
commute. In this paper, we use the string alpha' expansion in AdS-CFT to study
the corrections to the lambda=infinity result in powers of 1/lambda. For the
particular type of "jets" that we study, we find that (i) the naive expansion
in 1/lambda breaks down for certain initial conditions but (ii) the relative
corrections to the maximum stopping distance are small when 1/lambda is small.
More specifically, we find that the expansion in 1/lambda is well behaved for
jets whose stopping distance l_stop is in the range lambda^(-1/6) l_max <<
l_stop <~ l_max, but the expansion breaks down (and the fate of lambda=infinity
results is uncertain) for jets created in such a way that l_stop <<
lambda^(-1/6) l_max. The analysis requires assessing the effects of all
higher-derivative corrections to the supergravity action for the gravity dual.Comment: 45 pages, 8 figures [difference from v1: minor wording changes and
  section IV.D + a few refs added
Space-like (vs. time-like) collinear limits in QCD: is factorization violated?

We consider the singular behaviour of QCD scattering amplitudes in kinematical configurations where two or more momenta of the external partons become collinear. At the tree level, this behaviour is known to be controlled by factorization formulae in which the singular collinear factor is universal (process independent). We show that this strict (process-independent) factorization is not valid at one-loop and higher-loop orders in the case of the collinear limit in space-like regions (e.g., collinear radiation from initial-state partons). We introduce a generalized version of all-order collinear factorization, in which the space-like singular factors retain some dependence on the momentum and colour charge of the non-collinear partons. We present explicit results on one-loop and two-loop amplitudes for both the two-parton and multiparton collinear limits. At the level of square amplitudes and, more generally, cross sections in hadron--hadron collisions, the violation of strict collinear factorization has implications on the non-abelian structure of logarithmically-enhanced terms in perturbative calculations (starting from the next-to-next-to-leading order) and on various factorization issues of mass singularities (starting from the next-to-next-to-next-to-leading order)
Probing strongly coupled anisotropic plasma

We calculate the static potential, the drag force and the jet quenching
parameter in strongly coupled anisotropic N=4 super Yang-Mills plasma. We find
that the jet quenching is in general enhanced in presence of anisotropy
compared to the isotropic case and that its value depends strongly on the
direction of the moving quark and the direction along which the momentum
broadening occurs. The jet quenching is strongly enhanced for a quark moving
along the anisotropic direction and momentum broadening happens along the
transverse one. The parameter gets lower for a quark moving along the
transverse direction and the momentum broadening considered along the
anisotropic one. Finally, a weaker enhancement is observed when the quark moves
in the transverse plane and the broadening occurs on the same plane. The drag
force for quark motion parallel to the anisotropy is always enhanced. For
motion in the transverse space the drag force is enhanced compared to the
isotropic case only for quarks having velocity above a critical value. Below
this critical value the force is decreased. Moreover, the drag force along the
anisotropic direction is always stronger than the force in the transverse
space. The diffusion time follows exactly the inverse relations of the drag
forces. The static potential is decreased and stronger decrease observed for
quark-antiquark pair aligned along the anisotropic direction than the
transverse one. We finally comment on our results and elaborate on their
similarities and differences with the weakly coupled plasmas.Comment: 1+44 pages, 18 Figures; Added results on static force; Added
  references; version published in JHE
N=4 SYM model for soft interactions at high energy

In this paper we compare the prediction for high energy soft interactions in
the model of N=4 SYM, with the experimental data. It is shown that this model
is able to describe the total, elastic and inelastic cross sections and the
elastic slope with only three free parameters. However, the model failed to
obtain the cross sections for diffractive production, which was close to the
experimental data, giving small values for them. We believe that the theory of
N=4 SYM, of the order of $1/\lambda$ is needed to find the origin of large mass
diffraction.Comment: 14 pp, 10 figures in,eps file
Left-right symmetry at LHC and precise 1-loop low energy data

Despite many tests, even the Minimal Manifest Left-Right Symmetric Model
(MLRSM) has never been ultimately confirmed or falsified. LHC gives a new
possibility to test directly the most conservative version of left-right
symmetric models at so far not reachable energy scales. If we take into account
precise limits on the model which come from low energy processes, like the muon
decay, possible LHC signals are strongly limited through the correlations of
parameters among heavy neutrinos, heavy gauge bosons and heavy Higgs particles.
To illustrate the situation in the context of LHC, we consider the "golden"
process $pp \to e^+ N$. For instance, in a case of degenerate heavy neutrinos
and heavy Higgs masses at 15 TeV (in agreement with FCNC bounds) we get
$\sigma(pp \to e^+ N)>10$ fb at $\sqrt{s}=14$ TeV which is consistent with muon
decay data for a very limited $W_2$ masses in the range (3008 GeV, 3040 GeV).
Without restrictions coming from the muon data, $W_2$ masses would be in the
range (1.0 TeV, 3.5 TeV). Influence of heavy Higgs particles themselves on the
considered LHC process is negligible (the same is true for the light, SM
neutral Higgs scalar analog). In the paper decay modes of the right-handed
heavy gauge bosons and heavy neutrinos are also discussed. Both scenarios with
typical see-saw light-heavy neutrino mixings and the mixings which are
independent of heavy neutrino masses are considered. In the second case heavy
neutrino decays to the heavy charged gauge bosons not necessarily dominate over
decay modes which include only light, SM-like particles.Comment: 16 pages, 10 figs, KL-KS and new ATLAS limits taken into accoun
On the cubic interactions of massive and partially-massless higher spins
  in (A)dS

Cubic interactions of massive and partially-massless totally-symmetric
higher-spin fields in any constant-curvature background of dimension greater
than three are investigated. Making use of the ambient-space formalism, the
consistency condition for the traceless and transverse parts of the
parity-invariant interactions is recast into a system of partial differential
equations. The latter can be explicitly solved for given s_1-s_2-s_3 couplings
and the 2-2-2 and 3-3-2 examples are provided in detail for general choices of
the masses. On the other hand, the general solutions for the interactions
involving massive and massless fields are expressed in a compact form as
generating functions of all the consistent couplings. The St\"uckelberg
formulation of the cubic interactions as well as their massless limits are also
analyzed.Comment: 42 pages, 2 tables, LaTex. Comments on two-derivative couplings
  involving partially-massless spin-2 fields added, typos corrected, references
  added. v2: final version to appear in JHEP. v3: formulae (3.4) and (3.9)
  correcte
Inclusive production of a pair of hadrons separated by a large interval
  of rapidity in proton collisions

We consider within QCD collinear factorization the inclusive process $p+p\to
h_1+h_2+X$, where the pair of identified hadrons, $h_1,h_2$, having large
transverse momenta is produced in high-energy proton-proton collisions. In
particular, we concentrate on the kinematics where the two identified hadrons
in the final state are separated by a large interval of rapidity $\Delta y$. In
this case the (calculable) hard part of the reaction receives large higher
order corrections $\sim \alpha^n_s \Delta y^n$. We provide a theoretical input
for the resummation of such contributions with next-to-leading logarithmic
accuracy (NLA) in the BFKL approach. Specifically, we calculate in NLA the
vertex (impact-factor) for the inclusive production of the identified hadron.
This process has much in common with the widely discussed Mueller-Navelet jets
production and can be also used to access the BFKL dynamics at proton
colliders. Another application of the obtained identified-hadron vertex could
be the NLA BFKL description of inclusive forward hadron production in DIS.Comment: 29 pages, 9 figures; corrected few typos and added an acknowledgment;
  version to be published on JHEP. arXiv admin note: substantial text overlap
  with arXiv:1202.108
Tuning supersymmetric models at the LHC: A comparative analysis at
  two-loop level

We provide a comparative study of the fine tuning amount (Delta) at the
two-loop leading log level in supersymmetric models commonly used in SUSY
searches at the LHC. These are the constrained MSSM (CMSSM), non-universal
Higgs masses models (NUHM1, NUHM2), non-universal gaugino masses model (NUGM)
and GUT related gaugino masses models (NUGMd). Two definitions of the fine
tuning are used, the first (Delta_{max}) measures maximal fine-tuning wrt
individual parameters while the second (Delta_q) adds their contribution in
"quadrature". As a direct result of two theoretical constraints (the EW minimum
conditions), fine tuning (Delta_q) emerges as a suppressing factor (effective
prior) of the averaged likelihood (under the priors), under the integral of the
global probability of measuring the data (Bayesian evidence p(D)). For each
model, there is little difference between Delta_q, Delta_{max} in the region
allowed by the data, with similar behaviour as functions of the Higgs, gluino,
stop mass or SUSY scale (m_{susy}=(m_{\tilde t_1} m_{\tilde t_2})^{1/2}) or
dark matter and g-2 constraints. The analysis has the advantage that by
replacing any of these mass scales or constraints by their latest bounds one
easily infers for each model the value of Delta_q, Delta_{max} or vice versa.
For all models, minimal fine tuning is achieved for M_{higgs} near 115 GeV with
a Delta_q\approx Delta_{max}\approx 10 to 100 depending on the model, and in
the CMSSM this is actually a global minimum. Due to a strong ($\approx$
exponential) dependence of Delta on M_{higgs}, for a Higgs mass near 125 GeV,
the above values of Delta_q\approx Delta_{max} increase to between 500 and
1000. Possible corrections to these values are briefly discussed.Comment: 23 pages, 46 figures; references added; some clarifications (section
  2
Interacting Spin-2 Fields

We construct consistent theories of multiple interacting spin-2 fields in
arbitrary spacetime dimensions using a vielbein formulation. We show that these
theories have the additional primary constraints needed to eliminate potential
ghosts, to all orders in the fields, and to all orders beyond any decoupling
limit. We postulate that the number of spin-2 fields interacting at a single
vertex is limited by the number of spacetime dimensions. We then show that, for
the case of two spin-2 fields, the vielbein theory is equivalent to the
recently proposed theories of ghost-free massive gravity and bi-metric gravity.
The vielbein formulation greatly simplifies the proof that these theories have
an extra primary constraint which eliminates the Boulware-Deser ghost.Comment: 42 pages, 3 figures. v3 alternative argument using constrained
  spatial vielbeins has been removed (see footnote 3