We report on a search for millicharged particles (mCPs) produced in cosmic ray atmospheric interactions using data collected during the first science run of the LUX-ZEPLIN experiment. The mCPs produced by two processes-meson decay and proton bremsstrahlung-are considered in this study. This search utilized a novel signature unique to liquid xenon (LXe) time projection chambers, allowing sensitivity to mCPs with masses ranging from 10 to 1000 MeV/c(2) and fractional charges between 0.001 and 0.02 of the electron charge (e). With an exposure of 60 live days and a 5.5 metric ton fiducial mass, we observed no significant excess over background. This represents the first experimental search for atmospheric mCPs and the first search for mCPs using an underground LXe experiment.

Searches for dark matter with liquid xenon time projection chamber experiments have traditionally focused on the region of the parameter space that is characteristic of weakly interacting massive particles, ranging from a few GeV/$c^2$ to a few TeV/$c^2$. Models of dark matter with a mass much heavier than this are well motivated by early production mechanisms different from the standard thermal freeze-out, but they have generally been less explored experimentally. In this work, we present a re-analysis of the first science run (SR1) of the LZ experiment, with an exposure of $0.9$ tonne$\times$year, to search for ultraheavy particle dark matter. The signal topology consists of multiple energy deposits in the active region of the detector forming a straight line, from which the velocity of the incoming particle can be reconstructed on an event-by-event basis. Zero events with this topology were observed after applying the data selection calibrated on a simulated sample of signal-like events. New experimental constraints are derived, which rule out previously unexplored regions of the dark matter parameter space of spin-independent interactions beyond a mass of 10$^{17}$ GeV/$c^2$.

Following the first science results of the LUX-ZEPLIN (LZ) experiment, a dual-phase xenon time projection chamber operating from the Sanford Underground Research Facility in Lead, South Dakota, USA, we report the initial limits on a model-independent non-relativistic effective field theory describing the complete set of possible interactions of a weakly interacting massive particle (WIMP) with a nucleon. These results utilize the same 5.5 t fiducial mass and 60 live days of exposure collected for the LZ spin-independent and spin-dependent analyses while extending the upper limit of the energy region of interest by a factor of 7.5 to 270 keVnr. No significant excess in this high energy region is observed. Using a profile-likelihood ratio analysis, we report 90% confidence level exclusion limits on the coupling of each individual non-relativistic WIMP-nucleon operator for both elastic and inelastic interactions in the isoscalar and isovector bases.

LUX-ZEPLIN (LZ) is a tonne-scale experiment searching for direct dark matter interactions and other rare events. It is located at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. The core of the LZ detector is a dual-phase xenon time projection chamber (TPC), designed with the primary goal of detecting Weakly Interacting Massive Particles (WIMPs) via their induced low energy nuclear recoils. Surrounding the TPC, two veto detectors immersed in an ultra-pure water tank enable reducing background events to enhance the discovery potential. Intricate calibration systems are purposely designed to precisely understand the responses of these three detector volumes to various types of particle interactions and to demonstrate LZ's ability to discriminate between signals and backgrounds. In this paper, we present a comprehensive discussion of the key features, requirements, and performance of the LZ calibration systems, which play a crucial role in enabling LZ's WIMP-search and its broad science program. The thorough description of these calibration systems, with an emphasis on their novel aspects, is valuable for future calibration efforts in direct dark matter and other rare-event search experiments.

We estimate the amount of $^{37}$Ar produced in natural xenon via cosmic ray-induced spallation, an inevitable consequence of the transportation and storage of xenon on the Earth's surface. We then calculate the resulting $^{37}$Ar concentration in a 10-tonne payload~(similar to that of the LUX-ZEPLIN experiment) assuming a representative schedule of xenon purification, storage and delivery to the underground facility. Using the spallation model by Silberberg and Tsao, the sea level production rate of $^{37}$Ar in natural xenon is estimated to be 0.024~atoms/kg/day. Assuming the xenon is successively purified to remove radioactive contaminants in 1-tonne batches at a rate of 1~tonne/month, the average $^{37}$Ar activity after 10~tonnes are purified and transported underground is 0.058--0.090~$\mu$Bq/kg, depending on the degree of argon removal during above-ground purification. Such cosmogenic $^{37}$Ar will appear as a noticeable background in the early science data, while decaying with a 35~day half-life. This newly-noticed production mechanism of $^{37}$Ar should be considered when planning for future liquid xenon-based experiments.

We present a measurement of the W boson mass in W-->e(nu) decays using 1 fb-1 of data collected with the D0 detector during Run II of the Fermilab Tevatron collider. With a sample of 499830 W-->e(nu) candidate events, we measure M(W)=80.401+/-0.043 GeV. This is the most precise measurement from a single experiment.

A novel approach for designing the next generation of vertex detectors foresees to employ wafer-scale sensors that can be bent to truly cylindrical geometries after thinning them to thicknesses of 20-40$\mu$m. To solidify this concept, the feasibility of operating bent MAPS was demonstrated using 1.5$\times$3cm ALPIDE chips. Already with their thickness of 50$\mu$m, they can be successfully bent to radii of about 2cm without any signs of mechanical or electrical damage. During a subsequent characterisation using a 5.4GeV electron beam, it was further confirmed that they preserve their full electrical functionality as well as particle detection performance. In this article, the bending procedure and the setup used for characterisation are detailed. Furthermore, the analysis of the beam test, including the measurement of the detection efficiency as a function of beam position and local inclination angle, is discussed. The results show that the sensors maintain their excellent performance after bending to radii of 2cm, with detection efficiencies above 99.9% at typical operating conditions, paving the way towards a new class of detectors with unprecedented low material budget and ideal geometrical properties.

The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. The Higgs boson was the last missing component of the model. After observation of the Higgs boson, a measurement of the W boson mass provides a stringent test of the model. We measure the W boson mass, M W , using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at a 1.96 tera–electron volt center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. A sample of approximately 4 million W boson candidates is used to obtain M W = 80 , 433.5 ± 6.4 stat ± 6.9 syst = 80 , 433.5 ± 9.4 MeV / c 2 , the precision of which exceeds that of all previous measurements combined (stat, statistical uncertainty; syst, systematic uncertainty; MeV, mega–electron volts; c , speed of light in a vacuum). This measurement is in significant tension with the standard model expectation.

At the Fermilab Tevatron proton-antiproton ($p\bar{p}$) collider, high-mass electron-neutrino ($e\nu$) pairs are produced predominantly in the process $p \bar{p} \rightarrow W(\rightarrow e\nu) + X$. The asymmetry of the electron and positron yield as a function of their pseudorapidity constrain the slope of the ratio of the $u$- to $d$-quark parton distributions versus the fraction of the proton momentum carried by the quarks. This paper reports on the measurement of the electron-charge asymmetry using the full data set recorded by the Collider Detector at Fermilab in 2001--2011 and corresponding to 9.1~fb$^{-1}$ of integrated luminosity. The measurement significantly improves the precision of the Tevatron constraints on the parton-distribution functions of the proton. Numerical tables of the measurement are provided.

D.S. Akerib, 2 A.K. Al Musalhi, S.K. Alsum, C.S. Amarasinghe, A. Ames, 2 T.J. Anderson, 2 N. Angelides, H.M. Araújo, J.E. Armstrong, M. Arthurs, X. Bai, J. Balajthy, S. Balashov, J. Bang, J.W. Bargemann, D. Bauer, A. Baxter, P. Beltrame, E.P. Bernard, 16 A. Bernstein, A. Bhatti, A. Biekert, 16 T.P. Biesiadzinski, 2 H.J. Birch, G.M. Blockinger, B. Boxer, C.A.J. Brew, P. Brás, S. Burdin, J.K. Busenitz, M. Buuck, 2 R. Cabrita, M.C. Carmona-Benitez, M. Cascella, C. Chan, N.I. Chott, A. Cole, M.V. Converse, A. Cottle, 23 G. Cox, J.E. Cutter, C.E. Dahl, 23 L. de Viveiros, J.E.Y. Dobson, E. Druszkiewicz, S.R. Eriksen, A. Fan, 2 S. Fayer, N.M. Fearon, S. Fiorucci, H. Flaecher, E.D. Fraser, T. Fruth, R.J. Gaitskell, J. Genovesi, C. Ghag, E. Gibson, S. Gokhale, M.G.D. van der Grinten, C.B. Gwilliam, C.R. Hall, S.J. Haselschwardt, S.A. Hertel, M. Horn, D.Q. Huang, C.M. Ignarra, 2 O. Jahangir, R.S. James, W. Ji, 2 J. Johnson, A.C. Kaboth, 11 A.C. Kamaha, K. Kamdin, 15 K. Kazkaz, D. Khaitan, A. Khazov, I. Khurana, D. Kodroff, L. Korley, E.V. Korolkova, H. Kraus, S. Kravitz, L. Kreczko, B. Krikler, V.A. Kudryavtsev, E.A. Leason, K.T. Lesko, C. Levy, J. Li, J. Liao, J. Lin, 16 A. Lindote, R. Linehan, 2 W.H. Lippincott, 23 X. Liu, M.I. Lopes, E. Lopez Asamar, B. López Paredes, ∗ W. Lorenzon, S. Luitz, P.A. Majewski, A. Manalaysay, L. Manenti, R.L. Mannino, N. Marangou, M.E. McCarthy, D.N. McKinsey, 16 J. McLaughlin, E.H. Miller, 2 E. Mizrachi, 8 A. Monte, 23 M.E. Monzani, 2 J.A. Morad, J.D. Morales Mendoza, 2 E. Morrison, B.J. Mount, A.St.J. Murphy, D. Naim, A. Naylor, C. Nedlik, H.N. Nelson, F. Neves, J.A. Nikoleyczik, I. Olcina, 16 K.C. Oliver-Mallory, S. Pal, K.J. Palladino, 4 J. Palmer, N. Parveen, E.K. Pease, B. Penning, G. Pereira, A. Piepke, Y. Qie, J. Reichenbacher, C.A. Rhyne, A. Richards, Q. Riffard, 16 G.R.C. Rischbieter, R. Rosero, P. Rossiter, D. Santone, A.B.M.R. Sazzad, R.W. Schnee, P.R. Scovell, S. Shaw, T.A. Shutt, 2 J.J. Silk, C. Silva, R. Smith, 16 M. Solmaz, V.N. Solovov, P. Sorensen, I. Stancu, A. Stevens, K. Stifter, 2 B. Suerfu, 16 T.J. Sumner, N. Swanson, M. Szydagis, W.C. Taylor, R. Taylor, D.J. Temples, P.A. Terman, D.R. Tiedt, M. Timalsina, W.H. To, 2 M. Tripathi, D.R. Tronstad, W. Turner, U. Utku, A. Vaitkus, B. Wang, J.J. Wang, W. Wang, 27 J.R. Watson, 16 R.C. Webb, R.G. White, 2 T.J. Whitis, 1 M. Williams, F.L.H. Wolfs, D. Woodward, C.J. Wright, X. Xiang, J. Xu, M. Yeh, and P. Zarzhitsky SLAC National Accelerator Laboratory, Menlo Park, CA 94025-7015, USA Kavli Institute for Particle Astrophysics and Cosmology,

We report an observation of new bottom baryons produced in p (cid:1) p collisions at the Tevatron. Using 1 : 1 fb (cid:2) 1 of data collected by the CDF II detector, we observe four (cid:2) 0 b (cid:1) (cid:3) resonances in the fully reconstructed decay mode (cid:2) 0 b ! (cid:2) (cid:4) c (cid:1) (cid:2) , where (cid:2) (cid:4) c ! pK (cid:2) (cid:1) (cid:4) . We interpret these states as the (cid:3) (cid:5)(cid:1)(cid:6)(cid:3) b baryons and measure the following masses: m (cid:3) (cid:4) b (cid:7) 5807 : 8 (cid:4) 2 : 0 (cid:2) 2 : 2 (cid:5) stat : (cid:6) (cid:3) 1 : 7 (cid:5) syst : (cid:6) MeV =c 2 , m (cid:3)

Author(s): LUX-ZEPLIN, The; Collaboration; Akerib, DS; Musalhi, AK Al; Alsum, SK; Amarasinghe, CS; Ames, A; Anderson, TJ; Angelides, N; Araujo, HM; Armstrong, JE; Arthurs, M; Bai, X; Balajthy, J; Balashov, S; Bang, J; Bargemann, JW; Bauer, D; Baxter, A; Beltrame, P; Bernard, EP; Bernstein, A; Bhatti, A; Biekert, A; Biesiadzinski, TP; Birch, HJ; Blockinger, GM; Boxer, B; Brew, CAJ; Bras, P; Burdin, S; Busenitz, JK; Buuck, M; Cabrita, R; Carmona-Benitez, MC; Cascella, M; Chan, C; Chott, NI; Cole, A; Converse, MV; Cottle, A; Cox, G; Creaner, O; Cutter, JE; Dahl, CE; Viveiros, L de; Dobson, JEY; Druszkiewicz, E; Eriksen, SR; Fan, A; Fayer, S; Fearon, NM; Fiorucci, S; Flaecher, H; Fraser, ED; Fruth, T; Gaitskell, RJ; Genovesi, J; Ghag, C; Gibson, E; Gokhale, S; Grinten, MGD van der; Gwilliam, CB; Hall, CR; Hardy, CA; Haselschwardt, SJ; Hertel, SA; Horn, M; Huang, DQ; Ignarra, CM; Jahangir, O; James, RS; Ji, W; Johnson, J; Kaboth, AC; Kamaha, AC; Kamdin, K; Kazkaz, K; Khaitan, D; Khazov, A; Khurana, I; Kodroff, D; Korley, L; Korolkova, EV; Kraus, H | Abstract: The projected sensitivity of the LUX-ZEPLIN (LZ) experiment to two-neutrino and neutrinoless double beta decay of $^{134}$Xe is presented. LZ is a 10-tonne xenon time projection chamber optimized for the detection of dark matter particles, that is expected to start operating in 2021 at Sanford Underground Research Facility, USA. Its large mass of natural xenon provides an exceptional opportunity to search for the double beta decay of $^{134}$Xe, for which xenon detectors enriched in $^{136}$Xe are less effective. For the two-neutrino decay mode, LZ is predicted to exclude values of the half-life up to 1.7$\times$10$^{24}$ years at 90% confidence level (CL), and has a three-sigma observation potential of 8.7$\times$10$^{23}$ years, approaching the predictions of nuclear models. For the neutrinoless decay mode LZ, is projected to exclude values of the half-life up to 7.3$\times$10$^{24}$ years at 90% CL.

The LUX-ZEPLIN (LZ) experiment will enable a neutrinoless double beta decay search in parallel to the main science goal of discovering dark matter particle interactions. We report the expected LZ sensitivity to 136 Xe neutrinoless double beta decay, taking advantage of the significant ( > 600 kg) 136 Xe mass contained within the active volume of LZ without isotopic enrichment. After 1000 live-days, the median exclusion sensitivity to the half-life of 136 Xe is projected to be 1.06 × 10 26 years (90% confidence level), similar to existing constraints. We also report the expected sensitivity of a possible subsequent dedicated exposure using 90% enrichment with 136 Xe at 1.06 × 10 27 years.

Author(s): Akerib, DS; Akerlof, CW; Alqahtani, A; Alsum, SK; Anderson, TJ; Angelides, N; Araujo, HM; Armstrong, JE; Arthurs, M; Bai, X; Balajthy, J; Balashov, S; Bang, J; Baxter, A; Bensinger, J; Bernard, EP; Bernstein, A; Bhatti, A; Biekert, A; Biesiadzinski, TP; Birch, HJ; Boast, KE; Boxer, B; Bras, P; Buckley, JH; Bugaev, VV; Burdin, S; Busenitz, JK; Cabrita, R; Carels, C; Carlsmith, DL; Benitez, MC Carmona; Cascella, M; Chan, C; Chott, NI; Cole, A; Cottle, A; Cutter, JE; Dahl, CE; Viveiros, L de; Dobson, JEY; Druszkiewicz, E; Edberg, TK; Eriksen, SR; Fan, A; Fiorucci, S; Flaecher, H; Fraser, ED; Fruth, T; Gaitskell, RJ; Genovesi, J; Ghag, C; Gibson, E; Gilchriese, MGD; Gokhale, S; Grinten, MGD van der; Hall, CR; Harrison, A; Haselschwardt, SJ; Hertel, SA; Hor, JYK; Horn, M; Huang, DQ; Ignarra, CM; Jahangir, O; Ji, W; Johnson, J; Kaboth, AC; Kamaha, AC; Kamdin, K; Kazkaz, K; Khaitan, D; Khazov, A; Khurana, I; Kocher, CD; Korley, L; Korolkova, EV; Kras, J; Kraus, H; Kravitz, S; Kreczko, L; Krikler, B; Kudryavtsev, VA; Leason, EA; Lee, J | Abstract: The LUX-ZEPLIN (LZ) experiment will enable a neutrinoless double beta decay search in parallel to the main science goal of discovering dark matter particle interactions. We report the expected LZ sensitivity to $^{136}$Xe neutrinoless double beta decay, taking advantage of the significant ($g$600 kg) $^{136}$Xe mass contained within the active volume of LZ without isotopic enrichment. After 1000 live-days, the median exclusion sensitivity to the half-life of $^{136}$Xe is projected to be 1.06$\times$10$^{26}$ years (90% confidence level), similar to existing constraints. We also report the expected sensitivity of a possible subsequent dedicated exposure using 90% enrichment with $^{136}$Xe at 1.06$\times$10$^{27}$ years.

The LUX-ZEPLIN (LZ) experiment will enable a neutrinoless double beta decay search in parallel to the main science goal of discovering dark matter particle interactions. We report the expected LZ sensitivity to Xe-136 neutrinoless double beta decay, taking advantage of the significant (>600 kg) Xe-136 mass contained within the active volume of LZ without isotopic enrichment. After 1000 live-days, the median exclusion sensitivity to the half-life of Xe-136 is projected to be 1.06 x 10(26) years (90% confidence level), similar to existing constraints. We also report the expected sensitivity of a possible subsequent dedicated exposure using 90% enrichment with Xe-136 at 1.06 x 10(27) years.

The present document discusses plans for a compact, next-generation multi-purpose detector at the LHC as a follow-up to the present ALICE experiment. The aim is to build a nearly massless barrel detector consisting of truly cylindrical layers based on curved wafer-scale ultra-thin silicon sensors with MAPS technology, featuring an unprecedented low material budget of 0.05% X$_0$ per layer, with the innermost layers possibly positioned inside the beam pipe. In addition to superior tracking and vertexing capabilities over a wide momentum range down to a few tens of MeV/$c$, the detector will provide particle identification via time-of-flight determination with about 20~ps resolution. In addition, electron and photon identification will be performed in a separate shower detector. The proposed detector is conceived for studies of pp, pA and AA collisions at luminosities a factor of 20 to 50 times higher than possible with the upgraded ALICE detector, enabling a rich physics program ranging from measurements with electromagnetic probes at ultra-low transverse momenta to precision physics in the charm and beauty sector.

We report on a search for a spin-zero non-standard model particle in proton-antiproton collisions collected by the Collider Detector at Fermilab at a center-of-mass-energy of 1.96 TeV. This particle, the phi boson, is expected to decay into a bottom-antibottom quark pair and to be produced in association with at least one bottom quark. The data sample consists of events with three jets identified as initiated by bottom quarks and corresponds to 5.4 fb(-1) of integrated luminosity. In each event, the invariant mass of the two most energetic jets is studied by looking for deviations from the multijet background, which is modeled using data. No evidence is found for such a particle. Exclusion upper limits ranging from 20 to 2 pb are set for the product of production cross sections times branching fraction for the hypothetical phi boson with mass between 100 and 300 GeV/c(2). These are the most stringent constraints to date.