1,864 research outputs found
Inclusive SUSY searches at the LHC
I summarize the status of the inclusive SUSY searches conducted by the ATLAS
and CMS experiments using the 20 fb-1 of 8 TeV LHC data in the all inclusive, 0
lepton, >=1 lepton and >=2 lepton final states. Current searches show that data
are consistent with the SM. The impact of this consistency was explored on a
rich variety of SUSY scenarios and simplified models, examples of which I
present here.Comment: To appear in the proceedings of the 49th Rencontres de Moriond: QCD
and Hadronic Interactions, La Thuile, Italy, 22-29 March 201
Search for Natural SUSY with inclusive search strategies at the LHC using the CMS detector
Natural SUSY suggests the existence of light stop quarks, accessible at the
LHC, which are the focus of a dedicated CMS search program. I present two
inclusive CMS searches that look for TeV scale colored sparticles in final
states with jets, b-tagged jets and missing transverse energy performed using
up to 19.4fb-1 of 8TeV LHC proton-proton data. No deviation from the Standard
Model was observed in these searches, and the implications for this was shown
for several simplified model scenarios and phenomenological MSSM.Comment: Proceedings for The European Physical Society Conference on High
Energy Physics - EPS-HEP2013, 18-24 July 2013, Stockholm, Swede
Status of CMS dark matter searches in 2011
We present the status of dark matter searches performed by the Compact Muon
Solenoid Experiment using 7 TeV pp data collected by the CERN Large Hadron
Collider in 2010 and 2011. The majority of the results shown here were obtained
using 1.1 fb-1 of data. We give highlights from analyses searching for
candidates such as WIMPs, gravitinos, axinos and TeV scale particles. All
observations so far were found to be consistent with the Standard Model
predictions. The search results were used to set exclusion limits on various
new physics scenarios.Comment: Contribution to the proceedings of Balkan Workshop 2011 (BW2011, 28
August - 1 September 2011, Donji Milanovac, Serbia
Digging deeper into SUSY parameter space with the CMS experiment
The classic searches for supersymmetry have not given any strong indication
for new physics. Therefore CMS is designing dedicated searches to target the
more difficult and specific supersymmetry scenarios. This contribution present
three such recent searches based on 13 TeV proton-proton collisions recorded
with the CMS detector in 2016, 2017 and 2018: a search for heavy gluinos
cascading via heavy next-to-lightest neutralino in final states with boosted Z
bosons and missing transverse momentum; a search for compressed supersymmetry
in final states with soft taus; and a search for compressed, long-lived
charginos in hadronic final states with disappearing tracks.Comment: Contribution to the proceedings of 40th International Conference on
High Energy physics - ICHEP2020, July 28 - August 6, 2020, Prague, Czech
Republic (virtual meeting
Model Inference with Reference Priors
We describe the application of model inference based on reference priors to
two concrete examples in high energy physics: the determination of the CKM
matrix parameters rhobar and etabar and the determination of the parameters m_0
and m_1/2 in a simplified version of the CMSSM SUSY model. We show how a
1-dimensional reference posterior can be mapped to the n-dimensional (n-D)
parameter space of the given class of models, under a minimal set of conditions
on the n-D function. This reference-based function can be used as a prior for
the next iteration of inference, using Bayes' theorem recursively.Comment: Proceedings of PHYSTAT1
Reconciling thermal leptogenesis with the gravitino problem in SUSY models with mixed axion/axino dark matter
Successful implementation of thermal leptogenesis requires re-heat
temperatures T_R\agt 2\times 10^9 GeV, in apparent conflict with SUSY models
with TeV-scale gravitinos, which require much lower T_R in order to avoid Big
Bang Nucleosynthesis (BBN) constraints. We show that mixed axion/axino dark
matter can reconcile thermal leptogenesis with the gravitino problem in models
with m_{\tG}\agt 30 TeV, a rather high Peccei-Quinn breaking scale and an
initial mis-alignment angle \theta_i < 1. We calculate axion and axino dark
matter production from four sources, and impose BBN constraints on long-lived
gravitinos and neutralinos. Moreover, we discuss several SUSY models which
naturally have gravitino masses of the order of tens of TeV. We find a
reconciliation difficult in Yukawa-unified SUSY and in AMSB with a wino-like
lightest neutralino. However, T_R\sim 10^{10}-10^{12} GeV can easily be
achieved in effective SUSY and in models based on mixed moduli-anomaly
mediation. Consequences of this scenario include: 1. an LHC SUSY discovery
should be consistent with SUSY models with a large gravitino mass, 2. an
apparent neutralino relic abundance \Omega_{\tz_1}h^2\alt 1, 3. no WIMP direct
or indirect detection signals should be found, and 4. the axion mass should be
less than \sim 10^{-6} eV, somewhat below the conventional range which is
explored by microwave cavity axion detection experiments.Comment: 25 pages including 15 .eps figures; updated version to coincide with
published versio
Prospects for Yukawa Unified SO(10) SUSY GUTs at the CERN LHC
The requirement of t-b-\tau Yukawa coupling unification is common in simple
grand unified models based on the gauge group SO(10), and it also places a
severe constraint on the expected spectrum of superpartners. For Yukawa-unified
models with \mu >0, the spectrum is characterized by three mass scales: {\it
i}). first and second generation scalars in the multi-TeV range, {\it ii}).
third generation scalars, \mu and m_A in the few-TeV range and {\it iii}).
gluinos in the \sim 350-500 GeV range with chargino masses around 100-160 GeV.
In such a scenario, gluino pair production should occur at large rates at the
CERN LHC, followed by gluino three-body decays into neutralinos or charginos.
Discovery of Yukawa-unified SUSY at the LHC should hence be possible with only
1 fb^{-1} of integrated luminosity, by tagging multi-jet events with 2--3
isolated leptons, without relying on missing E_T. A characteristic dilepton
mass edge should easily be apparent above Standard Model background. Combining
dileptons with b-jets, along with the gluino pair production cross section
information, should allow for gluino and neutralino mass reconstruction. A
secondary corroborative signal should be visible at higher integrated
luminosity in the W1Z2-> 3\ell channel, and should exhibit the same dilepton
mass edge as in the gluino cascade decay signal.Comment: 25 pages including 18 EPS figure
Thermal leptogenesis and the gravitino problem in the Asaka-Yanagida axion/axino dark matter scenario
A successful implementation of thermal leptogenesis requires the re-heat
temperature after inflation T_R to exceed ~2\times 10^9 GeV. Such a high T_R
value typically leads to an overproduction of gravitinos in the early universe,
which will cause conflicts, mainly with BBN constraints. Asaka and Yanagida
(AY) have proposed that these two issues can be reconciled in the context of
the Peccei-Quinn augmented MSSM (PQMSSM) if one adopts a mass hierarchy
m(sparticle)>m(gravitino)>m(axino), with m(axino) keV. We calculate the relic
abundance of mixed axion/axino dark matter in the AY scenario, and investigate
under what conditions a value of T_R sufficient for thermal leptogenesis can be
generated. A high value of PQ breaking scale f_a is needed to suppress
overproduction of axinos, while a small vacuum misalignment angle \theta_i is
needed to suppress overproduction of axions. The large value of f_a results in
late decaying neutralinos. To avoid BBN constraints, the AY scenario requires a
low thermal abundance of neutralinos and high values of neutralino mass. We
include entropy production from late decaying saxions, and find the saxion
needs to be typically at least several times heavier than the gravitino. A
viable AY scenario suggests that LHC should discover a spectrum of SUSY
particles consistent with weak scale supergravity; that the apparent neutralino
abundance is low; that a possible axion detection signal (probably with m_axion
in the sub-micro-eV range) should occur, but no direct or indirect signals for
WIMP dark matter should be observed.Comment: 28 pages including 21 .eps figures; high resolution pdf version
available at http://www.nhn.ou.edu/~bae
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