Ryan Reece
(University of Pennsylvania)
15/08/2013, 08:30
Physics Beyond the Standard Model
oral presentation
"The LHC has brought a new level of sensitivity to TeV-scale new physics. Tau leptons can have preferred couplings to possible new physics, including Z' bosons motivated by grand unified theories. Hadronic tau decays are one of the most difficult final states to identify at hadron colliders like the LHC. ATLAS has multivariate techniques for identifying hadronic tau decays using Boosted...
Dr
Joseph Virzi
(Lawrence Berkeley National Laboratory)
15/08/2013, 08:50
Physics Beyond the Standard Model
oral presentation
We search for the pair production of a new heavy quark,
assuming the new quark has a significant branching ratio to decay into a Z boson and a Standard Model top (t) or bottom (b) quark.
For a new bottom-like quark B, we focus on the decay channel B \rightarrow Zb; for a new top-like quark T, we target the decay channel T \rightarrow Zt. The search uses a dataset corresponding to 14.3...
Saptaparna Bhattacharya
(Brown University)
15/08/2013, 09:10
Physics Beyond the Standard Model
oral presentation
We present searches for massive top and bottom quark partners at CMS using data collected at sqrt(s)=7 and 8 TeV. Such partners can be seen in 4th generation models, or can be found in models predicting vector-like quarks to solve the Hierarchy problem and stabilize the Higgs mass. The searches span a range of final states, from multi-leptonic to entirely hadronic, and limits are set on mass...
Pramod Lamichhane
(Wayne State University)
15/08/2013, 10:30
Physics Beyond the Standard Model
oral presentation
We report a search for contact interactions due to quark and lepton substructure manifest in production of µ+ µ- and e+e- pairs. The search is performed using the full data set recorded by CMS at √s = 8 TeV corresponding to integrated luminosity of 20.6 fb-1 for dimuons and 19.6 fb-1 for dielectrons. The dilepton yields for invariant masses above 300 GeV are found to be consistent with...
Dr
Mark Cooke
(LBNL)
15/08/2013, 10:50
Physics Beyond the Standard Model
oral presentation
Despite observations by the ATLAS and CMS experiments of a new particle consistent with the Standard Model Higgs boson, the mechanism of electroweak symmetry breaking remains undetermined. Further, the question of naturalness remains open. Supersymmetry provides elegant insights into these problems, but so far no evidence of such signals has been found. An alternative class of models are...
Claudia Seitz
(Rutgers University)
15/08/2013, 11:10
Physics Beyond the Standard Model
oral presentation
A search for three-jet hadronic resonance production in pp collisions at a center-of-mass energy of 8 TeV using 19.5/fb of data collected by the CMS experiment in 2012 is presented. The search method is model-independent for events with high jet multiplicity and large sum jet pT; however, event selection is optimized using an R-parity-violating supersymmetric model with gluino pair production...
Steven Farrell
(University of California Irvine)
15/08/2013, 13:30
Physics Beyond the Standard Model
oral presentation
Supersymmetry offers an elegant solution to the hierarchy problem and can provide a candidate for dark matter. As the limits on squark and gluino masses are pushed beyond the TeV range, direct production of charginos and neutralinos can become the dominant sparticle production at the LHC. Also, light charginos and neutralinos are favored in "Natural SUSY" models with small fine-tuning of the...
Mr
Brett Jackson
(University of Pennsylvania)
15/08/2013, 13:50
Physics Beyond the Standard Model
oral presentation
The search for the electroweak production of supersymmetric particles decaying into final states containing two leptons and missing energy was performed using the full 8 TeV dataset of proton-proton collisions recorded using the ATLAS experiment. The scenarios considered in this analysis were the production of two gauginos and slepton pair production. In both of these scenarios, the...
Xiaowen Lei
(University of Arizona)
15/08/2013, 14:10
Physics Beyond the Standard Model
oral presentation
A search is presented for exotic processes that result in final states containing jets including at least one b jet, sizable missing transverse momentum, and a pair of leptons with the same electric charge. There are several models that predict an enhanced rate of production of such events beyond the expectations of the Standard Model. The ones considered here are pair production of chiral b'...
Mr
Ryan Kelley
(University of California, San Diego)
15/08/2013, 14:30
Physics Beyond the Standard Model
oral presentation
A search for new physics is performed using events with same-sign isolated leptons and jets in the final state. The results are based on the full sample of proton-proton collisions at a center-of-mass energy of 8 TeV with the CMS detector and corresponding to an integrated luminosity of 19.5 fb-1. In order to be sensitive to a wide variety of possible signals beyond the Standard Model, we...
Mr
Angelo Monteux
(UCSC)
15/08/2013, 14:50
Physics Beyond the Standard Model
oral presentation
Motivated by null LHC searches for R-parity conserving SUSY, I will present the general structure of RPV couplings in presence of a Froggatt-Nielsen horizontal symmetry. For sub-TeV SUSY, lepton number must be an accidental symmetry, while baryonic RPV allows natural low-energy SUSY. The upper limit for the magnitude of the largest RPV coupling is 10^{-3} (from dinucleon decay) while the...
Michael Hance
(LBNL)
15/08/2013, 15:10
Physics Beyond the Standard Model
oral presentation
A model independent search for new physics in multilepton final states is presented using 20 inverse femtobarns of proton-proton collisions at a center-of-mass energy of 8 TeV collected by the ATLAS experiment at the CERN Large Hadron Collider. Events with three or more leptons are categorized based on their flavor content and presence of a Z-boson candidate. Signal regions are constructed...
Brock Tweedie
(Boston University)
15/08/2013, 16:00
Physics Beyond the Standard Model
oral presentation
If the lighter stop eigenstate decays directly to two jets via baryonic R-parity violation, it could have escaped existing LHC and Tevatron searches, even for masses as small as 100~GeV. The traditional approach to such a direct RPV stop pair search is to identify a bump in the joint spectrum of dijet pairs in four-jet events. However, this style of search seems to be in a losing race. As...
Thomas Danielson
(University of California - Santa Barbara)
15/08/2013, 16:20
Physics Beyond the Standard Model
oral presentation
Two searches for gluino-mediated supersymmetry are presented based on events with large missing transverse energy and multiple jets, with some of the jets being identified as a bottom-quark jet. These searches cover two separate final states, one containing exactly zero isolated leptons, and the other containing exactly one isolated muon or electron. Both searches have been performed using...
Dr
Keith Ulmer
(University of Colorado, Boulder)
15/08/2013, 16:40
Physics Beyond the Standard Model
oral presentation
The sensitivity for CMS searches for supersymmetry is evaluated in the context of an upgraded LHC at a center-of-mass energy of 14 TeV and an integrated luminosity of 300 fb-1. Results for several key searches for supersymmetry are presented including direct and gluino-mediated stop and sbottom production and electroweak production of supersymmetric particles.
Nikita Blinov
(TRIUMF/University of British Columbia)
15/08/2013, 17:00
Physics Beyond the Standard Model
oral presentation
The scalar potential of the Minimal Supersymmetric Standard Model (MSSM)
admits the existence of vacua with non-vanishing expectation values of
electrically and colour charged fields. If such minimima are deep enough,
the physical electroweak vacuum is rendered unstable by quantum tunneling.
By comparing the lifetime of the electroweak vacuum with the age of the
universe, the MSSM...
Dr
Jordi Salvado
(Wisconsin IceCube Particle Astrophysics Center (WIPAC) and Department of Physics University of Wisconsin, Madison)
16/08/2013, 09:00
Physics Beyond the Standard Model
oral presentation
Recent cosmological measurements favors additional relativistic energy
density beyond the one provided by the three active neutrinos and
photons of the Standard Model(SM), suggesting the need of new light
states in the theory beyond those of the SM. Another alternative is
that this increase comes from the decay of some new form of heavy
matter into the SM neutrinos. In this talk I will...
Dr
Andrea Albert
(The Ohio State University)
16/08/2013, 09:20
Physics Beyond the Standard Model
oral presentation
There is overwhelming evidence that non-baryonic dark matter constitutes ~27% of the energy density of the universe. Weakly Interacting Massive Particles are promising dark matter candidates that may produce monochromatic gamma rays via annihilation or decay. Such interactions would produce a narrow spectral line in the Galactic diffuse gamma-ray energy spectrum. We have searched for...
Peter Garbincius
(Fermilab)
16/08/2013, 10:30
Physics Beyond the Standard Model
oral presentation
The DO Collaboration has published three measurements of the like-sign dimuon charge asymmetry in p pbar collisions at the Fermilab Tevatron collider. The result is significantly different from the standard model prediction. In this talk we present the final measurement of this CP violating asymmetry, using the full 10 fb-1 of data collected during Run II, and discuss its possible interpretations.
Mr
Daniel Chao
(Caltech)
16/08/2013, 10:50
Physics Beyond the Standard Model
oral presentation
We present the measurement of B -> D(*) tau nu decay, which is sensitive at tree
level to New Physics contributions in the form of a charged Higgs boson. The
measured branching fraction is 3.4 sigma larger than the SM predictions, and
excludes the 2HDM of type 2 with a 99.8% confidence level for any value of
tan(beta)/mHiggs.
Additional studies of the momentum transfered to the...
Alan Eisner
(U.C. Santa Cruz)
16/08/2013, 11:10
Physics Beyond the Standard Model
oral presentation
We report on studies of flavor-changing neutral current decays of B mesons,
recently performed using the large data set collected with the BaBar detector.
Sensitivity to New Physics is tested through measurements of decay rates,
rate asymmetries, and CP asymmetries, in several b -> s gamma, b -> s l+l-,
b -> d gamma, and b -> d l+l- processes, as well as B -> K(*) nu anti-nu decays.
Dr
Aleksey Sher
(TRIUMF)
16/08/2013, 11:30
Physics Beyond the Standard Model
oral presentation
The PIENU experiment at TRIUMF aims to perform a precision measurement of the branching ratio of the helicity-suppressed pion decay, R = $\Gamma (\pi^+ \to e\nu + \pi^+ \to e\nu\gamma)/\Gamma (\pi^+ \to \mu\nu + \pi^+ \to \mu\nu\gamma)$. This ratio provides the most stringent test of the lepton-muon universality within the Standard Model and is currently predicted by the Standard Model to a...
Dr
Eugenia Puccio
(Stanford)
16/08/2013, 11:50
Physics Beyond the Standard Model
oral presentation
We present a search for fourteen lepton-number violating
processes B --> X-l+l+, where X- = K-, pi-, rho-, K*-, or anti-p,
and l+ = e+ or mu+, with a sample of about 470 million B anti-B pairs
collected with the BaBar detector at the PEP-II
asymmetric-energy e+e- collider at SLAC.
Prof.
Frank Porter
(Caltech)
16/08/2013, 14:30
Physics Beyond the Standard Model
oral presentation
The BABAR Collaboration has an intensive program of studying hadronic
cross sections at low-energy e+e- collisions, accessible at BaBar via
initial-state radiation. Our measurements allow significant improvements
in the precision of the predicted value of the muon anomalous magnetic
moment. These improvements are necessary for shedding light on the
current ~3.5 sigma difference between...
Brendan Kiburg
(Fermilab)
16/08/2013, 14:50
Physics Beyond the Standard Model
oral presentation
The Muon g-2 experiment at Fermilab will measure the anomalous magnetic moment of the muon, $a_{\mu}$, to 0.14 ppm. With a factor of four improved precision over the statistically limited Brookhaven E821 experiment, we will test the 3.6 $\sigma$ discrepancy between the Standard Model theory prediction and experimental results. Possible sources of this hint of new physics will be described and...
Mr
Keita Fukushima
(University of Hawaii at Manoa)
16/08/2013, 15:10
Physics Beyond the Standard Model
oral presentation
g-2 correction has been accurately measured in the E821 experiment at Brookhaven National Lab (BNL). Theoretical calculations of the loop corrections to the fermion bremsstrahlung predict the observations quite well. Yet there remains a $~10^-4% > 3\sigma$ difference between experiment and theory.
One way that this discrepancy can be interpreted is by new candidate particles running in the...
Mr
Omar Moreno
(Santa Cruz Institute for Particle Physics/University of California, Santa Cruz)
16/08/2013, 15:30
Physics Beyond the Standard Model
oral presentation
The Heavy Photon Search (HPS) is a new experiment at Jefferson Lab which will search for heavy $U(1)$ vector bosons (heavy/dark photons) in the mass range of 20 MeV/$c^2$ to 1 GeV/$c^2$. Dark photons in this mass range are theoretically favorable and may mediate dark matter interactions. The dark photon couples to electric charge through kinetic mixing with the photon, allowing its production...
Betrand Echenard
(Caltech)
16/08/2013, 15:50
Physics Beyond the Standard Model
oral presentation
Among dark matter theories, the possibility of dark sector(s) has recently
received much attention. This class of models introduces a new dark sector
with WIMP-like dark matter particles charged under a new Abelian gauge
group. The corresponding gauge boson, dubbed a dark photon, must be
lighter than a few GeV to explain recent astrophysical and terrestrial
anomalies. The dark photon...
David Yaylali
(University of Hawaii)
16/08/2013, 16:10
Physics Beyond the Standard Model
oral presentation
Recent developments have suggested that the dark sector may be much more complex than previously imagined. As a result, models such as Dynamical Dark Matter --- in which there are multiple dark-matter components which are only semi-stable but nevertheless contribute non-trivially to $\Omega_{\rm CDM}$ --- merit further study. One interesting potential signal which arises in such contexts...
Prof.
Roland Allen
(Department of Physics and Astronomy, Texas A&M University)
16/08/2013, 16:30
Physics Beyond the Standard Model
oral presentation
The present talk is based on arXiv:1101.0586 [hep-th], with some clarifications and additions, and a greater emphasis on the connection to standard physics. There has always been a remarkably close relationship between the partition function of statistical physics and the path integral of field theory. Here we argue that this is no coincidence, and that nature can be interpreted as a...
