Light Neutralino Dark Matter in the NMSSM

Neutralino dark matter is generally assumed to be relatively heavy, with a mass near the electroweak scale. This does not necessarily need to be the case, however. In the Next-to-Minimal Supersymmetric Standard Model (NMSSM) and other supersymmetric models with an extended Higgs sector, a very light CP-odd Higgs boson can naturally arise making it possible for a very light neutralino to annihilate efficiently enough to avoid being overproduced in the early Universe. In this article, we explore the characteristics of a supersymmetric model needed to include a very light neutralino, 100 MeV < \mcnone < 20 GeV, using the NMSSM as a prototype. We discuss the most important constraints from Upsilon decays, $b \to s \gamma$, $B_s \to \mu^+ \mu^-$ and the magnetic moment of the muon, and find that a light bino or singlino neutralino is allowed, and can be generated with the appropriate relic density. It has previously been shown that the positive detection of dark matter claimed by the DAMA collaboration can be reconciled with other direct dark matter experiments such as CDMS II if the dark matter particle is rather light, between about 6 and 9 GeV. A singlino or bino-like neutralino could easily fall within this range of masses within the NMSSM. Additionally, models with sub-GeV neutralinos may be capable of generating the 511 keV gamma-ray emission observed from the galactic bulge by the INTEGRAL/SPI experiment. We also point out measurements which can be performed immediately at CLEO, BaBar and Belle using existing data to discover or significantly constrain this scenario.Comment: References updated, accepted for publication in PR

Search for Leptoquarks and 4th generation Quarks at CDF

At Run II of the Fermilab Tevatron, the CDF experiment provides good sensitivity for either discovery or setting limits on 1st and 2nd generation scalar, or 3rd generation vector, leptoquark pair-production, where each leptoquark decays to a charged lepton and a quark with variable branching ratio {beta}, or decays to a neutrino and quark with branching ratio (1 - {beta}). By comparison with the theoretical expectations, we set mass limits, in some cases as a function of {beta}. New quark generations are predicted in various scenarios for physics beyond the Standard Model. Here we include results from searches for t' and for b' production. The t' is searched for in decays to W{sub q} and the b' in decays to Z{sup 0}b. All of these measurements are based on an integrated luminosity of 200-350 pb{sup -1}, taken at {radical}s = 1.96 TeV

Pediatric Dermatologist UC Davis School of Medicine Department of Dermatology

The University of California, Davis, School of Medicine, Department of Dermatology, is recruiting for a PediatricDermatologist in the Clinical X series or Health Sciences Clinical Professor (HSCP) series at the Assistant/Associate/FullProfessor level based on experience and qualifications. The appointment may be made up to 100%.Basic Qualifications: Candidates must possess an MD or MD/PhD, can be board eligible, but must be board-certified in dermatology at the time ofstarting employment and must be eligible for medical licensure in the State of California. Candidates must also be board eligible in pediatric dermatology at the time of starting employment and board certified within2 years of starting employment. Successful completion of an approved dermatology residency training program (ACGME accredited) and successful completionof an approved pediatric dermatology fellowship program (ACGME accredited). Demonstrated proficiency in the teaching of students and housestaff. Service including committees, leadership ability, and community outreach. Ability to work cooperatively and collegially within a diverse environment. Ability to adhere to policies and procedures, and leadership experience and abilities. Selected candidates will be expected to participate in clinical care, teaching, research and university service.Preferred Qualifications: Experience and interest in clinical research.For first consideration, applications should be received by October 15, 2019; however, the position will be open until filled throughSeptember 30, 2020. The following information is required: Cover Letter, Curriculum Vitae, contact information for 3-5 referencesand Statement of Contributions to Diversity. Please visit http://academicaffairs.ucdavis.edu/diversity/equity_inclusion/index.htmlfor information about why diversity statements are requested and guidelines for writing a diversity statement. Please upload thisinformation and apply online at https://recruit.ucdavis.edu/apply/JPF03038.The position is in Sacramento, California. The Department of Dermatology (http://www.ucdmc.ucdavis.edu/dermatology) is a majorclinical care, research, and teaching department in the School of Medicine. Our faculty are engaged in multiple collaborations withother Schools and UC Davis campus departments, research centers, clinical centers, and primary care networks, and thus allpositions require flexibility in local job locations in addition to the Department of Dermatology. This includes the Veteran'sAdministration, UCD Medical Center Campus, and other community centers.UC Davis commits to inclusion excellence by advancing equity, diversity and inclusion in all that we do. We are an AffirmativeAction/Equal Opportunity employer, and particularly encourage applications from members of historically underrepresentedracial/ethnic groups, women, individuals with disabilities, veterans, LGBTQ community members, and others who demonstrate theability to help us achieve our vision of a diverse and inclusive community. For the complete University of Californianondiscrimination and affirmative action policy, see: http://policy.ucop.edu/doc/4000376/NondiscrimAffirmAct. If you needaccommodation due to a disability, please contact the recruiting department.Under Federal law, the University of California may employ only individuals who are legally able to work in the United States asestablished by providing documents as specified in the Immigration Reform and Control Act of 1986. Certain UC Davis positionsfunded by federal contracts or sub-contracts require the selected candidates to pass an E-Verify check. More information is availableat http://www.uscis.gov/e-verify.UC Davis is a smoke &amp; tobacco-free campus (http://breathefree.ucdavis.edu)

A Unified Dark Matter Model in sUED

We propose a dark matter model with standard model singlet extension of the universal extra dimension model (sUED) to explain the recent observations of ATIC, PPB-BETS, PAMELA and DAMA. Other than the standard model fields propagating in the bulk of a 5-dimensional space, one fermion field and one scalar field are introduced and both are standard model singlets. The zero mode of the new fermion is identified as the right-handed neutrino, while its first KK mode is the lightest KK-odd particle and the dark matter candidate. The cosmic ray spectra from ATIC and PPB-BETS determine the dark matter particle mass and hence the fifth dimension compactification scale to be 1.0-1.6 TeV. The zero mode of the singlet scalar field with a mass below 1 GeV provides an attractive force between dark matter particles, which allows a Sommerfeld enhancement to boost the annihilation cross section in the Galactic halo to explain the PAMELA data. The DAMA annual modulation results are explained by coupling the same scalar field to the electron via a higher-dimensional operator. We analyze the model parameter space that can satisfy the dark matter relic abundance and accommodate all the dark matter detection experiments. We also consider constraints from the diffuse extragalactic gamma-ray background, which can be satisfied if the dark matter particle and the first KK-mode of the scalar field have highly degenerate masses

Report of the Dark Energy Task Force

Dark energy appears to be the dominant component of the physical Universe, yet there is no persuasive theoretical explanation for its existence or magnitude. The acceleration of the Universe is, along with dark matter, the observed phenomenon that most directly demonstrates that our theories of fundamental particles and gravity are either incorrect or incomplete. Most experts believe that nothing short of a revolution in our understanding of fundamental physics will be required to achieve a full understanding of the cosmic acceleration. For these reasons, the nature of dark energy ranks among the very most compelling of all outstanding problems in physical science. These circumstances demand an ambitious observational program to determine the dark energy properties as well as possible

The VLBA Imaging and Polarimetry Survey at 5 GHz

We present the first results of the VLBA Imaging and Polarimetry Survey (VIPS), a 5 GHz VLBI survey of 1,127 sources with flat radio spectra. Through automated data reduction and imaging routines, we have produced publicly available I, Q, and U images and have detected polarized flux density from 37% of the sources. We have also developed an algorithm to use each source's I image to automatically classify it as a point-like source, a core-jet, a compact symmetric object (CSO) candidate, or a complex source. The mean ratio of the polarized to total 5 GHz flux density for VIPS sources with detected polarized flux density ranges from 1% to 20% with a median value of about 5%. We have also found significant evidence that the directions of the jets in core-jet systems tend to be perpendicular to the electric vector position angles (EVPAs). The data is consistent with a scenario in which ~24% of the polarized core-jets have EVPAs that are anti-aligned with the directions of their jet components and which have a substantial amount of Faraday rotation. In addition to these initial results, plans for future follow-up observations are discussed.Comment: 36 pages, 3 tables, 13 figures; accepted for publication in Ap

Three Gravitational Lenses for the Price of One: Enhanced Strong Lensing through Galaxy Clustering

We report the serendipitous discovery of two strong gravitational lens candidates (ACS J160919+6532 and ACS J160910+6532) in deep images obtained with the Advanced Camera for Surveys on the Hubble Space Telescope, each less than 40 arcsec from the previously known gravitational lens system CLASS B1608+656. The redshifts of both lens galaxies have been measured with Keck and Gemini: one is a member of a small galaxy group at z~0.63, which also includes the lensing galaxy in the B1608+656 system, and the second is a member of a foreground group at z~0.43. By measuring the effective radii and surface brightnesses of the two lens galaxies, we infer their velocity dispersions based on the passively evolving Fundamental Plane (FP) relation. Elliptical isothermal lens mass models are able to explain their image configurations within the lens hypothesis, with a velocity dispersion compatible with that estimated from the FP for a reasonable source-redshift range. Based on the large number of massive early-type galaxies in the field and the number-density of faint blue galaxies, the presence of two additional lens systems around CLASS B1608+656 is not unlikely in hindsight. Gravitational lens galaxies are predominantly early-type galaxies, which are clustered, and the lensed quasar host galaxies are also clustered. Therefore, obtaining deep high-resolution images of the fields around known strong lens systems is an excellent method of enhancing the probability of finding additional strong gravitational lens systems.Comment: Submitted to ApJ. 8 pages, 6 figure

KPiX, An Array of Self Triggered Charge Sensitive Cells Generating Digital Time and Amplitude Information

The Silicon Detector proposed for the International Linear Collider (ILC) requires electronic read-out that can be tightly coupled to the silicon detectors envisioned for the tracker and the electromagnetic calorimeter. The KPiX is a 1024-channel read-out chip that bump-bonds to the detector and communicates through a few digital signals, power, and detector bias. The KPiX front-end is a low-noise dual-range charge-amplifier with a dynamic range of 17 bit, achieved by autonomous switching of the feedback capacitor. The device takes advantage of the ILC duty cycle of 1 ms trains at 5 Hz rate by lowering the supply current after the data acquisition cycle for an average power consumption of &lt;20 {micro}W/channel. During the 1 ms train, up to four events exceeding a programmable threshold can be stored, the amplitude as a voltage on a capacitor for subsequent digitization, the event time in digital format. The chip can be configured for other than ILC applications