40 research outputs found
Limiting SUSY compressed spectra scenarios
Typical searches for supersymmetry cannot test models in which the two
lightest particles have a small ("compressed") mass splitting, due to the small
momentum of the particles produced in the decay of the second-to-lightest
particle. However, datasets with large missing transverse momentum () can generically search for invisible particle production and
therefore provide constraints on such models. We apply data from the ATLAS
mono-jet (jet+) and vector-boson-fusion (forward jets and
) searches to such models. The two datasets have
complementary sensitivity, but in all cases experimental limits are at least
five times weaker than theoretical predictions
Kaluza-Klein gluons at 100 TeV: NLO corrections
We explore the reach of a 100 TeV proton collider to discover KK gluons in a
warped extra dimension. These particles are templates for color adjoint vectors
that couple dominantly to the top quark. We examine their production rate at
NLO in the six-flavor m-ACOT scheme for a variety of reference models defining
their coupling to quarks, largely inspired by the RS model of a warped extra
dimension. In agreement with previous calculations aimed at lower energy
machines, we find that the NLO corrections are typically negative, resulting in
a -factor of around 0.7 (depending on the model) and with a residual scale
dependence on the order of , greater than the variation from the
scale exhibited by the na\"{i}ve LO estimate.Comment: 33 pages, 5 figures, 2 table
Role of anisotropy in the spin-dimer compound BaCuSi2O6
We present results of magnetisation and electron paramagnetic resonance
experiments on the spin-dimer system BaCuSi2O6. Evidence indicates that the
origin of anisotropic terms in the spin Hamiltonian is from magnetic dipolar
interactions. Axial symmetry-breaking is on a very small energy scale of ~11
mK, confirming Bose Einstein condensation critical scaling over an extended
temperature range in the vicinity of the quantum critical point.Comment: 4 pages, 4 figure
Protophobic Fifth-Force Interpretation of the Observed Anomaly in \u3csup\u3e8\u3c/sup\u3eBe Nuclear Transitions
Recently a 6.8σ anomaly has been reported in the opening angle and invariant mass distributions of e+e− pairs produced in 8Be nuclear transitions. The data are explained by a 17 MeV vector gauge boson X that is produced in the decay of an excited state to the ground state, 8Be∗ → 8Be X, and then decays through X → e+e−. The X boson mediates a fifth force with a characteristic range of 12 fm and has millicharged couplings to up and down quarks and electrons, and a proton coupling that is suppressed relative to neutrons. The protophobic X boson may also alleviate the current 3.6σ discrepancy between the predicted and measured values of the muon’s anomalous magnetic moment
Protophobic Fifth-Force Interpretation of the Observed Anomaly in \u3csup\u3e8\u3c/sup\u3eBe Nuclear Transitions
Recently a 6.8σ anomaly has been reported in the opening angle and invariant mass distributions of e+e− pairs produced in 8Be nuclear transitions. The data are explained by a 17 MeV vector gauge boson X that is produced in the decay of an excited state to the ground state, 8Be∗ → 8Be X, and then decays through X → e+e−. The X boson mediates a fifth force with a characteristic range of 12 fm and has millicharged couplings to up and down quarks and electrons, and a proton coupling that is suppressed relative to neutrons. The protophobic X boson may also alleviate the current 3.6σ discrepancy between the predicted and measured values of the muon’s anomalous magnetic moment
SUSY_FLAVOR v2.5: a computational tool for FCNC and CP-violating processes in the MSSM
We present SUSY_FLAVOR version 2.5 - a Fortran 77 program that calculates
low-energy flavor observables in the general -parity conserving MSSM. For a
set of MSSM parameters as input, the code gives predictions for: 1. Electric
dipole moments of the leptons and the neutron. 2. Anomalous magnetic moments
(i.e. ) of the leptons. 3. Radiative lepton decays ( and
). 4. Rare Kaon decays (
and ). 5. Leptonic decays (,
, and ). 6. Radiative
decays (). 7. Rare decays of top quark to Higgs boson
(). 8. processes (, , and mixing). SUSY_FLAVOR performs the resummation of
all chirally enhanced corrections, i.e. takes into account the effects enhanced
by and/or large trilinear soft mixing terms to all orders in
perturbation theory. All calculations are done using exact diagonalization of
the sfermion mass matrices. Comparing to previous versions, in SUSY_FLAVOR v2.5
parameter initialization in SLHA2 format has been significantly generalized and
simplified, so that program accepts without modifications most of the output
files produced by other codes calculating MSSM spectra and processes. In
addition, the routine calculating branching ratios for rare decays of top quark
to Higgs boson has been included. The program can be obtained from
www.fuw.edu.pl/susy_flavor.Comment: Updated from arXiv:1003.4260 [hep-ph] (SUSY_FLAVOR v1 manual), 61
pages; updated sections on modified user interface and on newly added
processes. SUSY_FLAVOR code available at http://www.fuw.edu.pl/susy_flavo
Goldstone Fermion Dark Matter
We propose that the fermionic superpartner of a weak-scale Goldstone boson
can be a natural WIMP candidate. The p-wave annihilation of this `Goldstone
fermion' into pairs of Goldstone bosons automatically generates the correct
relic abundance, whereas the XENON100 direct detection bounds are evaded due to
suppressed couplings to the Standard Model. Further, it is able to avoid
indirect detection constraints because the relevant s-wave annihilations are
small. The interactions of the Goldstone supermultiplet can induce non-standard
Higgs decays and novel collider phenomenology.Comment: 25 pages, 6 figures. References added, minor typos corrected.
Submitted to JHE
Snowmass Theory Frontier Report
This report summarizes the recent progress and promising future directions in
theoretical high-energy physics (HEP) identified within the Theory Frontier of
the 2021 Snowmass Process.Comment: Contribution to the US Community Study on the Future of Particle
Physics (Snowmass 2021), v2: fixed typo
Dark sectors 2016 Workshop: community report
This report, based on the Dark Sectors workshop at SLAC in April 2016,
summarizes the scientific importance of searches for dark sector dark matter
and forces at masses beneath the weak-scale, the status of this broad
international field, the important milestones motivating future exploration,
and promising experimental opportunities to reach these milestones over the
next 5-10 years