Physical Sciences and Mathematics Commons^™

Cross-Section Measurement Of Virtual Photoproduction Of Iso-Triplet Three-Body Hypernucleus, ⋀Nn, T. Gogami, K. N. Suzuki, B. Pandey, K. Itabashi, S. Nagao, K. Okuyama, S. N. Nakamura, L. Tang, D. Abrams, T. Akiyama, D. Androic, K. Aniol, C. Ayerbe Gayoso, J. Bane, S. Barcus, J. Barrow, V. Bellini, H. Bhatt, D. Bhetuwal, D. Biswas, A. Camsonne, J. Castellanos, J-P. Chen, J. Chen, S. Covrig, D. Chrisman, R. Cruz-Torres, R. Das, E. Fuchey, K. Gnanvo, F. Garibaldi, T. Gautam, J. Gomez, P. Gueye, T.J. Hague, O. Hansen, W. Henry, F. Hauenstein, D. W. Higinbotham, C. E. Hyde, M. Kaneta, C. Keppel, T. Kutz, N. Lashley-Colthirst, S. Li, H. Liu, J. Mammei, P. Markowitz, R. E. Mcclellan, F. Meddi, D. Meekins, R. Michaels, M. Mihovilovic, A. Moyer, D. Nguyen, M. Nycz, V. Owen, C. Palatchi, S. Park, T. Petkovic, S. Premathilake, P.E. Reimer, J. Reinhold, S. Riordan, V. Rodriguez, C. Samanta, S. N. Santiesteban, B. Sawatzky, S. Širca, K. Slifer, T. Su, Y. Tian, Y. Toyama, K. Uehara, G. M. Urciuoli, D. Votaw, J. Williamson, B. Wojtsekhowski, S. A. Wood, B. Yale, Z. Ye, J. Zhang, X. Zheng

Physics Faculty Publications

Missing-mass spectroscopy with the ³H(e, e′K⁺) reaction was carried out at Jefferson Lab’s (JLab) Hall A in Oct–Nov, 2018. The differential cross section for the ³H(γ^∗, K⁺)Λnn was deduced at ω = Ee − E_e′ = 2.102 GeV and at the forward K⁺-scattering angle (0^° ≤ θ_γ∗K ≤ 5^°) in the laboratory frame. Given typical predicted energies and decay widths, which are (B_Λ, Γ) = (−0.25, 0.8) and (−0.55, 4.7) MeV, the cross sections were found …

Study Of ⋀N Fsi With ⋀ Quasi-Free Productions On The ³H (E, E'K⁺) X Reaction At Jlab, K. Itabashi, K. N. Suzuki, B. Pandey, K. Okuyama, T. Gogami, S. Nagao, S. N. Nakamura, L. Tang, D. Abrams, T. Akiyama, D. Androic, K. Aniol, C. Ayerbe Gayoso, J. Bane, S. Barcus, J. Barrow, V. Bellini, H. Bhatt, D. Bhetuwal, D. Biswas, A. Camsonne, J. Castellanos, J.-P. Chen, J. Chen, S. Covrig, D. Chrisman, R. Cruz-Torres, R. Das, E. Fuchey, K. Gnanvo, F. Garibaldi, T. Gautam, J. Gomez, P. Gueye, T. J. Hague, O. Hansen, W. Henry, F. Hauenstein, D. W. Higinbotham, C. E. Hyde, M. Kaneta, C. Keppel, T. Kutz, N. Lashley-Colthirst, S. Li, H. Liu, J. Mammei, P. Markowitz, R. E. Mcclellan, F. Meddi, D. Meekins, R. Michaels, M. Milhovilovic, A. Moyer, D. Nguyen, M. Nycz, V. Owen, C. Palatchi, S. Park, T. Petkovic, S. Premathilake, P. E. Reimer, J. Reinhold, S. Riordan, V. Rodriguez, C. Samanta, S. N. Santiesteban, B. Sawatzky, S. Širca, K. Slifer, T. Su, Y. Tian, Y. Toyama, K. Uehara, G. M. Urciuoli, D. Votaw, J. Williamson, B. Wojtsekhowski, S. A. Wood, B. Yale, Z. Ye, J. Zhang, X. Zheng

Physics Faculty Publications

An nnΛ is a neutral baryon system with no charge. The study of the pure Λ-neutron system such as nnΛ gives us information on the Λn interaction. The nnΛ search experiment (E12-17-003) was performed at JLab Hall A in 2018. In this article, the Λn FSI was investigated by a shape analysis of the ³H(e, e′K⁺)X missing mass spectrum, and a preliminary result for the Λn FSI study is given.

Coupled Dynamics Of Spin Qubits In Optical Dipole Microtraps: Application To The Error Analysis Of A Rydberg-Blockade Gate, L. V. Gerasimov, R. R. Yusupov, A. D. Moiseevsky, I. Vybornyi, K. S. Tikhonov, S. P. Kulik, S. S. Straupe, Charles I. Sukenik, D. V. Kupriyanov

Physics Faculty Publications

Single atoms in dipole microtraps or optical tweezers have recently become a promising platform for quantum computing and simulation. Here we report a detailed theoretical analysis of the physics underlying an implementation of a Rydberg two-qubit gate in such a system—a cornerstone protocol in quantum computing with single atoms. We focus on a blockade-type entangling gate and consider various decoherence processes limiting its performance in a real system. We provide numerical estimates for the limits on fidelity of the maximally entangled states and predict the full process matrix corresponding to the noisy two-qubit gate. We consider different excitation geometries and …

New Results At Jlab Describing Operating Lifetime Of Gaas Photo-Guns, M. Bruker, J. Grames, C. Hernández-García, M. Poelker, S. Zhang, V. Lizárraga-Rubio, C. Valerio-Lizárraga, Joshua T. Yoskowitz

Physics Faculty Publications

Polarized electrons from GaAs photocathodes have been key to some of the highest-impact results of the Jefferson Lab science program over the past 30 years. During this time, various studies have given insight into improving the operational lifetime of these photocathodes in DC high-voltage photo-guns while using lasers with spatial Gaussian profiles of typically 0.5 mm to 1 mm FWHM, cathode voltages of 100 kV to 130 kV, and a wide range of beam currents up to multiple mA. In this contribution, we show recent experimental data from a 100 kV to 180 kV setup and describe our progress at …

Toward The Determination Of The Gluon Helicity Distribution In The Nucleon From Lattice Quantum Chromodynamics, Colin Egerer, Bálint Joó, Joseph Karpie, Nikhil Karthik, Tanjib Khan, Christopher J. Monahan, Wayne Morris, Kostas Orginos, Anatoly Radyushkin, David G. Richards, Eloy Romero, Raza Sabbir Sufian, Savvas Zafeiropoulos

Physics Faculty Publications

We present the first exploratory lattice quantum chromodynamics (QCD) calculation of the polarized gluon Ioffe-time pseudodistribution in the nucleon. The Ioffe-time pseudodistribution provides a frame-independent and gauge-invariant framework to determine the gluon helicity in the nucleon from first principles. We employ a high-statistics computation using a 32³ × 64 lattice ensemble characterized by a 358 MeV pion mass and a 0.094 fm lattice spacing. We establish the pseudodistribution approach as a feasible method to address the proton spin puzzle with successive improvements in statistical and systematic uncertainties anticipated in the future. Within the statistical precision of our data, we …

Updated Analysis Of An Unexpected Correlation Between Dark Matter And Galactic Ellipticity, D. M. Winters, Alexandre Deur, X. Zheng

Physics Faculty Publications

We investigate a correlation between the dark matter content of elliptical galaxies and their ellipticity ϵ that was initially reported in 2014. We use new determinations of dark matter and ellipticities that are posterior to that time. Our data set consists of 237 elliptical galaxies passing a strict set of criteria that selects a homogeneous sample of typical elliptical galaxies. We find a relation between the mass-to-light ratio and ellipticity ϵ that is well fitted by M/L = (14.1 ± 5.4)ϵ, which agrees with the result reported in 2014. Our analysis includes 135 galaxies that were not in …

Beam-Recoil Transferred Polarization In K+Y Electroproduction In The Nucleon Resonance Region With Clas12, D. S. Carman, A. D'Angelo, L. Lanza, V. I. Mokeev, K. P. Adhikari, M. J. Amaryan, W. R. Armstrong, H. Atac, H. Avakian, C. Ayerbe Gayoso, N. A. Baltzell, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, A. Bianconi, A. S. Biselli, M. Bondi, S. Boiarinov, V. Ziegler

Physics Faculty Publications

Beam-recoil transferred polarizations for the exclusive electroproduction of K + Λ and K + Σ⁰ final states from an unpolarized proton target have been measured using the CLAS12 spectrometer at Jefferson Laboratory. The measurements at beam energies of 6.535 and 7.546 GeV span the range of four-momentum transfer Q² from 0.3 to 4.5 GeV² and invariant energy W from 1.6 to 2.4 GeV, while covering the full center-of-mass angular range of the K⁺. These new data extend the existing hyperon polarization data from CLAS in a similar kinematic range but from a significantly larger dataset. …

197 Mhz Waveguide Loaded Crabbing Cavity Design For The Electron-Ion Collider, Subashini De Silva, Jean Delayen, J. Guo, R. A. Rimmer, Z. Li, B. P. Xiao

Physics Faculty Publications

The Elec­tron-Ion Col­lider will re­quire crab­bing sys­tems at both hadron and elec­tron stor­age rings in order to reach the de­sired lu­mi­nos­ity goal. The 197 MHz crab cav­ity sys­tem is one of the crit­i­cal rf sys­tems of the collider. The crab cav­ity, based on the rf-di­pole de­sign, explores the op­tion of wave­guide load damp­ing to sup­press the higher order modes and meet the tight im­ped­ance spec­i­fi­ca­tions. The cav­ity is de­signed with com­pact dog-bone wave­guides with tran­si­tions to rec­tan­gu­lar wave-guides and wave­guide loads. This paper pre­sents the com­pact 197 MHz crab cav­ity de­sign with wave­guide damp­ing and other an­cil­lar­ies.

Searching For An Enhanced Signal Of The Onset Of Color Transparency In Baryons With D(E,E′P)N Scattering, Shujie Li, Carlos Yero, Jennifer Rittenhouse West, Clare Bennett, Wim Cosyn, Douglas Higinbotham, Misak Sargsian, Holly Szumila-Vance

Physics Faculty Publications

Observation of the onset of color transparency in baryons would provide a new means of studying the nuclear strong force and would be the first clear evidence of baryons transforming into a color-neutral point-like size in the nucleus as predicted by quantum chromodynamics. Recent C (e, e′p) results from electron-scattering did not observe the onset of color transparency (CT) in protons up to spacelike four-momentum transfers squared, Q² = 14.2 GeV ² . The traditional methods of searching for CT in (e, e′p) scattering use heavy targets favoring kinematics with already initially reduced final state interactions (FSIs) such that …

Collinear Factorization At Subasymptotic Kinematics And Validation In A Diquark Spectator Model, Juan V. Guerrero, Alberto Accardi

Physics Faculty Publications

We revisit the derivation of collinear factorization for Deep Inelastic Scattering at subasymptotic values of the four-momentum transfer squared, where the masses of the particles participating in the interaction cannot be neglected. By using an inclusive jet function to describe the scattered quark final state, we can restrict the needed parton kinematic approximations just to the four-momentum conservation of the hard scattering process, and explicitly expand the rest of the diagram in powers of the unobserved parton transverse momenta rather than neglecting those. This procedure provides one with more flexibility in fixing the virtuality of the scattered and recoiling partons …

𝒯, 𝒫-Odd Effects In The Luoh⁺ Cation, Daniel E. Maison, Leonid V. Skripnikov, Gleb Penyazkov, Matt Grau, Alexander N. Petrov

Physics Faculty Publications

The LuOH⁺ cation is a promising system to search for manifestations of time reversal and spatial parity violation effects. Such effects in LuOH⁺ induced by the electron electric dipole moment eEDM and the scalar-pseudoscalar interaction of the nucleus with electrons, characterized by k_s constant, in LuOH⁺ are studied. The enhancement factors, polarization in the external electric field, hyperfine interaction, and rovibrational structure are calculated. The study is required for the experiment preparation and extraction of the eEDM and k_s values from experimental data.

Magnetic Flux Expulsion In Superconducting Radio-Frequency Niobium Cavities Made From Cold Worked Niobium, Bashu D. Khanal, S. Balachandran, S. Chetri, P. J. Lee, P. Dhakal

Physics Faculty Publications

Trapped residual magnetic field during the cooldown of superconducting radio frequency (SRF) cavities is one of the primary source of RF residual losses leading to lower quality factor. Historically, SRF cavities have been fabricated from high purity fine grain niobium with grain size ~50 - 100 μm as well as large grain with grain size of the order of few centimeters. Non-uniform recrystallization of fine-grain Nb cavities after the post fabrication heat treatment leads to higher flux trapping during cooldown, hence the lower quality factor. We fabricated two 1.3 GHz single cell cavities from cold-worked niobium from different vendors and …

Lower Temperature Annealing Of Vapor Diffused Nb3Sn For Accelerator Cavities, Jayendrika K. Tiskumara, Jean R. Delayen, G. V. Eremeev, U. Pudasaini

Physics Faculty Publications

Nb₃Sn is a next-generation superconducting material for the accelerator cavities with higher critical temperature and superheating field, both twice compared to Nb. It promises superior performance and higher operating temperature than Nb, resulting in significant cost reduction. So far, the Sn vapor diffusion method is the most preferred and successful technique to coat niobium cavities with Nb₃Sn. Although several post-coating techniques (chemical, electrochemical, mechanical) have been explored to improve the surface quality of the coated surface, an effective process has yet to be found. Since there are only a few studies on the post-coating heat treatment …

Field Shielding Of NBT��N Based Multilayer Structure For Accelerating Cavities, Iresha Harshani Senevirathne, Jean R. Delayen, Alex Gurevich, D. R. Beverstock, A.-M. Valente-Feliciano

Physics Faculty Publications

Over the past few decades, bulk niobium (Nb) has been the material of choice for superconducting radio frequency (SRF) cavities used in particle accelerators to achieve higher accelerating gradients and lower RF losses. Multi-layer (SIS) structures consisting of alternating thin layers of superconductor(S) and insulator(I) deposited on a bulk Nb have been proposed to enhance the peak surface magnetic field and sustain a higher accelerating gradient. In this study, multilayers based NbTiN and AlN deposited on bulk Nb are used to test the proposed enhancement using the DC magnetic Hall probe technique. The technique detects a penetrating magnetic field through …

Improved Electrostatic Design Of The Jefferson Lab 300 Kv Dc Photogun And The Minimization Of Beam Deflection, M. A. Mamun, D. B. Bullard, J. R. Delayen, J. M. Grames, C. Hernandez-Garcia, Geoffrey A. Krafft, M. Poelker, R. Suleiman, S.A.K. Wijethunga

Physics Faculty Publications

An electron beam with high bunch charge and high repetition rate is required for electron cooling of the ion beam to achieve the high luminosity required for the proposed electron-ion colliders. An improved design of the 300 kV DC high voltage photogun at Jefferson Lab was incorporated toward overcoming the beam loss and space charge current limitation experienced in the original design. To reach the bunch charge goal of ~ few nC within 75 ps bunches, the existing DC high voltage photogun electrodes and anode-cathode gap were modified to increase the longitudinal electric field (Ez) at the photocathode. The anode-cathode …

Preliminary Results From Magnetic Field Scanning System For A Single-Cell Niobium Cavity, Ishwari Prasad Parajuli, Gianluigi Ciovati, Jean R. Delayen, Alex V. Gurevich

Physics Faculty Publications

One of the building blocks of modern particle accelerators is superconducting radiofrequency (SRF) cavities. Niobium is the material of choice to build such cavities, which operate at liquid helium temperature (2 - 4 K) and have some of the highest quality factors found in Nature. There are several sources of residual losses, one of them is trapped magnetic flux, which limits the quality factor in SRF cavities. The flux trapping mechanism depends on different niobium surface preparations and cool-down conditions. Suitable diagnostic tools are not yet available to study the effects of such conditions on magnetic flux trapping. A magnetic …

Samples For 3rd Harmonic Magnetometry Assessment Of Nbtin-Based Sis Structures, D.R. Beverstock, C.Z. Antoine, Jean R. Delayen, D. Manos, Iresha Harshani Senevirathne, J. K. Spradlin, A-M. Valente-Feliciano

Physics Faculty Publications

In the quest for alternative superconducting materials to bring accelerator cavity performance beyond the bulk niobium (Nb) intrinsic limits, a promising concept uses superconductor-insulator-superconductor (SIS) thin film structures that allows magnetic flux shielding in accelerator cavities to higher fields [1]. Candidate materials for such structures are NbTiN as the superconductor and AlN as the insulator. We have demonstrated high quality NbTiN and AlN deposited by reactive DC magnetron sputtering (DCMS), both for individual layers and multilayers. Interface quality has been assessed for bilayer stacks with 250 nm NbTiN layers and AlN thicknesses from 30 nm down to1 nm. These SIS …

Bunch Length Measurements At The Cebaf Injector At 130 Kv, Sunil Pokharel, M. W. Bruker, J. M. Grames, A. S. Hofler, R. Kazimi, Geoffrey A. Krafft, S. Zhang

Physics Faculty Publications

In this work, we investigated the evolution in bunch length of beams through the CEBAF injector for low to high charge per bunch. Using the General Particle Tracer (GPT), we have simulated the beams through the beamline of the CEBAF injector and analyzed the beam to get the bunch lengths at the location of chopper. We performed these simulations with the existing injector using a 130 kV gun voltage. Finally, we describe measurements to validate these simulations. The measurements have been done using chopper scanning technique for two injector laser drive frequency modes: one with 500 MHz, and another with …

Neutrino Energy Reconstruction From Semi-Inclusive Samples, R. González-Jiménez, M. B. Barbaro, J. A. Caballero, T. W. Donnelly, N. Jachowicz, G.D. Megias, K. Niewczas, A. Nikolakopoulos, J.W. Van Orden, J. M. Udías

Physics Faculty Publications

We study neutrino-nucleus charged-current reactions on finite nuclei for the situation in which an outgoing muon and a proton are detected in coincidence; i.e., we focus on semi-inclusive cross sections. We limit our attention to one-body current interactions (quasielastic scattering) and assess the impact of different nuclear effects in the determination of the neutrino energy. We identify the regions in phase space where the neutrino energy can be reconstructed relatively well and study whether the cross section in those regions is significant. Our results indicate that it is possible to filter more than 50% of all events according to the …

Application Of Image Processing Programs In Color Analysis Of Wood Photodegradation, Gabriel Joseph D. Plata, Ramon M. Delos Santos

Physics Faculty Publications

In general, polymer photodegradation is an important aspect of polymer science that is of great interest to chemistry, materials science, biology, and physics students who engage in this field of research. Wood consists of three main polymers, which makes it a good candidate for such photodegradation studies. Aside from structural changes based on chemical analysis, color change assessment can also be employed to check any extent of degradation on wood without the need for sophisticated analytical equipment. This study presents the application of two image processing programs in color analysis of wood photodegradation: ImageJ and Colormath library, which are Java-based …

Question 1: Ketchup Packets; Question 2: Dog Hair, Larry Weinstein

Physics Faculty Publications

Question 2: Dog hair How much dog hair is shed (and subsequently vacuumed) in the U.S. each year? How many ketchup packets are used in America every year?.

Question 1: Dinosaur Killer Crater; Question 2: Graduation Speeches, Larry Weinstein

Physics Faculty Publications

The Fermi Questions: In 2003, the "Dinosaur Killer" asteroid crater was imaged for the first time (see National Geographic News, March 7, 2003). The crater is believed to be 100 km in radius and 1 km deep. What was the kinetic energy of the asteroid that made the crater? Express your answer in joules and in megatons (1 MT = 4 ·10 J).

Solutions For Fermi Questions, April 2022, Larry Weinstein

Physics Faculty Publications

[Introduction] Answer: When an asteroid hits the Earth, it transfers thermal and kinetic energy to the ground. The kinetic energy moves rock and makes a crater. We'll start by estimating the kinetic energy needed to make a crater.

Solutions For Fermi Questions, May 2022, Larry Weinstein

Physics Faculty Publications

[Introduction] Question: If the James Webb Space Telescope could be turned to face the Earth, how small an object could it resolve? How does that compare to the Hubble Space Telescope?.

To answer this, we need to know the location of the JWST, its size, and the wavelengths it can image. (This is one of those Fermi questions where we're not really estimating, but we are calculating unusual order-of-magnitude answers.) The JWST is orbiting the Earth and Sun at the second Lagrange point, L2, which is located 1.5 × 10⁶ km beyond the Earth (so that the Sun, Earth and …

Question 1: Space Telescope; Question 2: Jwst2, Larry Weinstein

Physics Faculty Publications

[Introduction] Space telescope

Question 1: If the James Webb Space Telescope could be turned to face Earth, how small an object could it resolve? How does that compare to the Hubble Space Telescope? ...

Question 2: How much heat from Earth is blocked by the Sun and Earth shade of the James Webb Space Telescope? ...

Question: While I was at a Norfolk Tides baseball game, a foul ball landed in the section above me and showered some of my friends with beer. What is the probability of a foul ball landing directly in a cup of beer during one …

Solutions For Fermi Questions, March 2022, Larry Weinstein

Physics Faculty Publications

Answers the questions:

Question 1: Ketchup packets

How many ketchup packets are used in America every year?

Question 2: Dog hair

How much dog hair is shed (and subsequently vacuumed) in the U.S. each year?

Effect Of Duration Of 120 °C Baking On The Performance On Superconducting Radio Frequency Niobium Cavities, B. D. Khanal, P. Dhakal

Physics Faculty Publications

Over the last decade much attention was given in increasing the quality factor of superconducting radio frequency (SRF) cavities by impurity doping. Prior to the era of doping, the final cavity processing technique to achieve the high accelerating gradient includes the "in situ" low temperature baking of SRF cavities at temperature ~ 120 °C for several hours. Here, we present the results of a series of measurements on 1.3 GHz TESLA shape single-cell cavities with successive low temperature baking at 120 °C up to 96 hours. The experimental data were analyzed with available theory of superconductivity to elucidate the effect …

An Update To C12-21-004: Semi-Inclusive Deep Inelastic Scattering Measurements Of A = 3 Nuclei With Clas12 In Hall B, D. Gaskell, D. W. Higinbotham, C. Keith, C. Keppel, J. Maxwell, A. Tadepalli, D. Meekins, D. Nguyen, S. Stepanyan, H. Szumila-Vance, A. Denniston, O. Hen, J. Kahlbow, T. Kutz, J. R. Pybus, E. P. Segarra, C. Ayerbe-Gayoso, H. Bhatt, B. Devkota, J. Dunne, D. Dutta, L. El Fassi, A. Karki, M. Amarian, C. Fogler, F. Hauenstein, C. Hyde, G. Gavalian, L. B. Weinstein, S. Li, R. Cruz Torres, J. Rittenhouse West, Z. G. Xiao, Y. Wang, J. H. Xu, Z. H. Ye, Y. P. Zhang, K. Griffioen, P. Bosted, A. Bianconi, G. Costantini, M. Leali, S. Migliorati, L. Venturelli, V. Mascagna, A. Boyer, F. Benmokhtar, A. Gadsby, A. Parker, L. Baashen, B. Raue, W. J. Briscoe, S. Ratliff, A. Schmidt, E. Seroka, P. Sharp, P. G. Solazzo, I. I. Strakovsky, K. Adhikari, G. Niculescu, K.-T. Brinkmann, S. Diehl, A. Kripko, Sheren Alsalmi, Tyler J. Hague, A. Beck, S. Beck, E. Cohen, I. Korover, G. Johansson, C. Neuburger, E. Piasetzky, Michael Nycz, R. Capobianco, T. Haywars, F.-X. Girod, K. Joo, A. Kim, V. Klimenko, R. Santos, U. Shrestha, P. Simmerling, J. Richard, N. Trotta, B. Mckinnon, W. Brooks

Physics Faculty Publications

We propose to measure precision ratios of charged pion electroproduction in 10.6 GeV Semi-Inclusive Deep Inelastic Scattering from ²D, ³He and ³H targets in CLAS12 over a wide range of xB to test the flavor dependence of the EMC effect in the valence quark region. This trio of targets minimizes hadron attenuation effects while maximizing nuclear asymmetry and takes advantage of the tritium target that will be developed for the approved quasi-elastic experiment E12-20-005 [1]. The experiment will focus on z = En/v ≥ 0.3 to maximize the connection between the struck quark and the detected π±. Double ratios of …

Influence Of Boreal Summer Intraseasonal Oscillation On Rainfall Extremes In The Philippines, Lyndon Mark P. Olaguera, John A. Manalo, Jun Matsumoto

Physics Faculty Publications

This study investigates the impact of the northward/northwestward propagating 30–60-day mode of the boreal summer intraseasonal oscillation (BSISO) on the extreme rainfall events in the Philippines during the June–September (JJAS) season from 1979 to 2018. The Philippines domain is divided into the three latitudinal regions: Luzon region (13°–22°N), Visayas region (10°–13°N), and Mindanao region (5°–10°N) to account for the regional differences in the timing of extreme rainfall events. The probability density functions of JJAS rainfall are skewed towards higher values relative to the non-BSISO days in BSISO Phases 6–8, Phases 5–7, and Phases 4–6 over the Luzon, Visayas, and Mindanao …

Experimental Measurement Of Sharp Thz Absorption Signatures From Nucleic Acid Solutions In Nanofluidic Channels, Elliott R. Brown, Edgar A. Mendoza

Physics Faculty Publications

We report on the room-temperature experimental measurement of THz absorption signatures in aqueous, double-stranded nucleic acid solutions confined to the submicron silica channels on fused quartz substrates using THz frequency-domain (photomixing) spectroscopy. Three sharp (i.e., strong and narrow) signatures, ~10–20 GHz FWHM, are observed in the shortest base pair sample—small interfering, double-stranded (ds) RNA—in the range of 800 GHz to 1.1 THz. Three similar signatures are also observed in a 50-bp dsDNA ladder sample. For a 1-kbp dsDNA ladder sample, the three are still evident, but are broadened and weakened. For a 48.5-kbp sample (λ-DNA), no prominent signatures are observed, …