105 research outputs found
Measurement of ϒ production in pp collisions at √s = 2.76 TeV
The production of ϒ(1S), ϒ(2S) and ϒ(3S)
mesons decaying into the dimuon final state is studied with
the LHCb detector using a data sample corresponding to an
integrated luminosity of 3.3 pb−1 collected in proton–proton
collisions at a centre-of-mass energy of √s = 2.76 TeV. The
differential production cross-sections times dimuon branching
fractions are measured as functions of the ϒ transverse
momentum and rapidity, over the ranges pT < 15 GeV/c
and 2.0 < y < 4.5. The total cross-sections in this kinematic
region, assuming unpolarised production, are measured to be
σ (pp → ϒ(1S)X) × B
ϒ(1S)→μ+μ−
= 1.111 ± 0.043 ± 0.044 nb,
σ (pp → ϒ(2S)X) × B
ϒ(2S)→μ+μ−
= 0.264 ± 0.023 ± 0.011 nb,
σ (pp → ϒ(3S)X) × B
ϒ(3S)→μ+μ−
= 0.159 ± 0.020 ± 0.007 nb,
where the first uncertainty is statistical and the second systematic
Study of the doubly charmed tetraquark T+cc
Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar T+cc tetraquark with a quark content of ccu⎯⎯⎯d⎯⎯⎯ and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector T+cc state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the T+cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed
SuperB Progress Reports -- Physics
SuperB is a high luminosity e+e- collider that will be able to indirectly probe new physics at energy scales far beyond the reach of any man made accelerator planned or in existence. Just as detailed understanding of the Standard Model of particle physics was developed from stringent constraints imposed by flavour changing processes between quarks, the detailed structure of any new physics is severely constrained by flavour processes. In order to elucidate this structure it is necessary to perform a number of complementary studies of a set of golden channels. With these measurements in hand, the pattern of deviations from the Standard Model behavior can be used as a test of the structure of new physics. If new physics is found at the LHC, then the many golden measurements from SuperB will help decode the subtle nature of the new physics. However if no new particles are found at the LHC, SuperB will be able to search for new physics at energy scales up to 10-100 TeV. In either scenario, flavour physics measurements that can be made at SuperB play a pivotal role in understanding the nature of physics beyond the Standard Model. Examples for using the interplay between measurements to discriminate New Physics models are discussed in this document. SuperB is a Super Flavour Factory, in addition to studying large samples of B_{u,d,s}, D and tau decays, SuperB has a broad physics programme that includes spectroscopy both in terms of the Standard Model and exotica, and precision measurements of sin^2theta_W. In addition to performing CP violation measurements at the Y(4S) and phi(3770), SuperB will test CPT in these systems, and lepton universality in a number of different processes. The multitude of rare decay measurements possible at SuperB can be used to constrain scenarios of physics beyond the Standard Model
SuperB Progress Reports - Physics
SuperB is a high luminosity e+e- collider that will be able to indirectly probe new physics at energy scales far beyond the reach of any man made accelerator planned or in existence. Just as detailed understanding of the Standard Model of particle physics was developed from stringent constraints imposed by flavour changing processes between quarks, the detailed structure of any new physics is severely constrained by flavour processes. In order to elucidate this structure it is necessary to perform a number of complementary studies of a set of golden channels. With these measurements in hand, the pattern of deviations from the Standard Model behavior can be used as a test of the structure of new physics. If new physics is found at the LHC, then the many golden measurements from SuperB will help decode the subtle nature of the new physics. However if no new particles are found at the LHC, SuperB will be able to search for new physics at energy scales up to 10-100 TeV. In either scenario, flavour physics measurements that can be made at SuperB play a pivotal role in understanding the nature of physics beyond the Standard Model. Examples for using the interplay between measurements to discriminate New Physics models are discussed in this document. SuperB is a Super Flavour Factory, in addition to studying large samples of B_{u,d,s}, D and tau decays, SuperB has a broad physics programme that includes spectroscopy both in terms of t he Standard Model and exotica, and precision measurements of sin^2theta_W. In addition to performing CP violation measurements at the Y(4S) and phi(3770), SuperB will test CPT in these systems, and lepton universality in a number of different processes. The multitude of rare decay measurements possible at SuperB can be used to constrain scenarios of physics beyond the Standard Model. ..
SuperB Progress Reports - Detector
none240This report describes the present status of the detector design for SuperB. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008. The other three reports relate to Physics, Accelerator and Computing.noneE. Grauges; G. Donvito; V. Spinoso; M. Manghisoni; V. Re; G. Traversi; G. Eigen; D. Fehlker; L. Helleve; A. Carbone; R. Di Sipio; A. Gabrielli; D. Galli; F. Giorgi; U. Marconi; S. Perazzini; C. Sbarra; V. Vagnoni; S. Valentinetti; M. Villa; A. Zoccoli; C. Cheng; A. Chivukula; D. Doll; B. Echenard; D. Hitlin; P. Ongmongkolkul; F. Porter; A. Rakitin; M. Thomas; R. Zhu; G. Tatishvili; R. Andreassen; C. Fabby; B. Meadows; A. Simpson; M. Sokoloff; K. Tomko; A. Fella; M. Andreotti; W. Baldini; R. Calabrese; V. Carassiti; G. Cibinetto; A. Cotta Ramusino; A. Gianoli; E. Luppi; M. Munerato; V. Santoro; L. Tomassetti; D. Stoker; O. Bezshyyko; G. Dolinska; N. Arnaud; C. Beigbeder; F. Bogard; D. Breton; L. Burmistrov; D. Charlet; J. Maalmi; L. Perez; V. Puill; A. Stocchi; V. Tocut; S. Wallon; G. Wormser; D. Brown; A. Calcaterra; R. de Sangro; G. Felici; G. Finocchiaro; P. Patteri; I. Peruzzi; M. Piccolo; M. Rama; S. Fantinel; G. Maron; E. Ben-Haim; G. Calderini; H. Lebbolo; G. Marchiori; R. Cenci; A. Jawahery; D.A. Roberts; D. Lindemann; P. Patel; S. Robertson; D. Swersky; P. Biassoni; M. Citterio; V. Liberali; F. Palombo; A. Stabile; S. Stracka; A. Aloisio; S. Cavaliere; G. De Nardo; A. Doria; R. Giordano; A. Ordine; S. Pardi; G. Russo; C. Sciacca; A.Y. Barniakov; M.Y. Barniakov; V.E. Blinov; V.P. Druzhinin; V.B.. Golubev; S.A. Kononov; E. Kravchenko; A.P. Onuchin; S.I. Serednyakov; Y.I. Skovpen; E.P. Solodov; M. Bellato; M. Benettoni; M. Corvo; A. Crescente; F. Dal Corso; C. Fanin; E. Feltresi; N. Gagliardi; M. Morandin; M. Posocco; M. Rotondo; R. Stroili; C. Andreoli; L. Gaioni; E. Pozzati; L. Ratti; V. Speziali; D. Aisa; M. Bizzarri; C. Cecchi; S. Germani; P. Lubrano; E. Manoni; A. Papi; A. Piluso ; A. Rossi; M. Lebeau; C. Avanzini; G. Batignani; S. Bettarini; F. Bosi; M. Ceccanti; A. Cervelli; A. Ciampa; F. Crescioli; M. Dell’Orso; D. Fabiani; F. Forti; P. Giannetti; M. Giorgi; S. Gregucci; A. Lusiani; P. Mammini; G. Marchiori; M. Massa; E. Mazzoni; F. Morsani; N. Neri; E. Paoloni; E. Paoloni; M. Piendibene; A. Profeti; G. Rizzo; L. Sartori; J. Walsh; E. Yurtsev; D.M. Asner; J. E. Fast; R.T. Kouzes; A. Bevan; F. Gannaway; J. Mistry; C. Walker; C.A.J. Brew; R.E. Coath; J.P. Crooks; R.M. Harper; A. Lintern; A. Nichols; M. Staniztki; R. Turchetta; F.F. Wilson; V. Bocci; G. Chiodi; R. Faccini; C. Gargiulo; D. Pinci; L. Recchia; D. Ruggieri; A. Di Simone; P. Branchini; A. Passeri; F. Ruggieri; E. Spiriti; D. Aston; M. Convery; G. Dubois-Felsmann; W. Dunwoodie; M. Kelsey; P. Kim; M. Kocian; D. Leith; S. Luitz; D. MacFarlane; B. Ratcliff; M. Sullivan; J. Va’vra; W. Wisniewski; W. Yang; K. Shougaev; A. Soffer; F. Bianchi; D. Gamba; G. Giraudo; P. Mereu; G. Dalla Betta; G. Fontana; G. Soncini; M. Bomben; L. Bosisio; P. Cristaudo; G. Giacomini; D. Jugovaz; L. Lanceri; I. Rashevskaya; G. Venier; L. Vitale; R. Henderson; J.-F. Caron; C. Hearty; P. Lu; R. So; P. Taras; A. Agarwal; J. Franta; J.M. RoneyE., Grauges; G., Donvito; V., Spinoso; M., Manghisoni; V., Re; G., Traversi; G., Eigen; D., Fehlker; L., Helleve; A., Carbone; R., Di Sipio; A., Gabrielli; D., Galli; F., Giorgi; U., Marconi; S., Perazzini; C., Sbarra; V., Vagnoni; S., Valentinetti; M., Villa; A., Zoccoli; C., Cheng; A., Chivukula; D., Doll; B., Echenard; D., Hitlin; P., Ongmongkolkul; F., Porter; A., Rakitin; M., Thomas; R., Zhu; G., Tatishvili; R., Andreassen; C., Fabby; B., Meadows; A., Simpson; M., Sokoloff; K., Tomko; A., Fella; Andreotti, Mirco; Baldini, Wander; Calabrese, Roberto; Carassiti, Vittore; Cibinetto, Gianluigi; COTTA RAMUSINO, Angelo; Gianoli, Alberto; Luppi, Eleonora; Munerato, Mauro; Santoro, Valentina; Tomassetti, Luca; D., Stoker; O., Bezshyyko; G., Dolinska; N., Arnaud; C., Beigbeder; F., Bogard; D., Breton; L., Burmistrov; D., Charlet; J., Maalmi; L., Perez; V., Puill; A., Stocchi; V., Tocut; S., Wallon; G., Wormser; D., Brown; A., Calcaterra; R., de Sangro; G., Felici; G., Finocchiaro; P., Patteri; I., Peruzzi; M., Piccolo; M., Rama; S., Fantinel; G., Maron; E., Ben Haim; G., Calderini; H., Lebbolo; G., Marchiori; R., Cenci; A., Jawahery; D. A., Roberts; D., Lindemann; P., Patel; S., Robertson; D., Swersky; P., Biassoni; M., Citterio; V., Liberali; F., Palombo; A., Stabile; S., Stracka; A., Aloisio; S., Cavaliere; G., De Nardo; A., Doria; R., Giordano; A., Ordine; S., Pardi; G., Russo; C., Sciacca; A. Y., Barniakov; M. Y., Barniakov; V. E., Blinov; V. P., Druzhinin; Golubev, V. B.; S. A., Kononov; E., Kravchenko; A. P., Onuchin; S. I., Serednyakov; Y. I., Skovpen; E. P., Solodov; M., Bellato; M., Benettoni; Corvo, Marco; A., Crescente; F., Dal Corso; C., Fanin; E., Feltresi; N., Gagliardi; M., Morandin; M., Posocco; M., Rotondo; R., Stroili; C., Andreoli; L., Gaioni; E., Pozzati; L., Ratti; V., Speziali; D., Aisa; M., Bizzarri; C., Cecchi; S., Germani; P., Lubrano; E., Manoni; A., Papi; A., Piluso; A., Rossi; M., Lebeau; C., Avanzini; G., Batignani; S., Bettarini; F., Bosi; M., Ceccanti; A., Cervelli; A., Ciampa; F., Crescioli; M., Dell’Orso; D., Fabiani; F., Forti; P., Giannetti; M., Giorgi; S., Gregucci; A., Lusiani; P., Mammini; G., Marchiori; M., Massa; E., Mazzoni; F., Morsani; N., Neri; E., Paoloni; E., Paoloni; M., Piendibene; A., Profeti; G., Rizzo; L., Sartori; J., Walsh; E., Yurtsev; D. M., Asner; J. E., Fast; R. T., Kouzes; A., Bevan; F., Gannaway; J., Mistry; C., Walker; C. A. J., Brew; R. E., Coath; J. P., Crooks; R. M., Harper; A., Lintern; A., Nichols; M., Staniztki; R., Turchetta; F. F., Wilson; V., Bocci; G., Chiodi; R., Faccini; C., Gargiulo; D., Pinci; L., Recchia; D., Ruggieri; A., Di Simone; P., Branchini; A., Passeri; F., Ruggieri; E., Spiriti; D., Aston; M., Convery; G., Dubois Felsmann; W., Dunwoodie; M., Kelsey; P., Kim; M., Kocian; D., Leith; S., Luitz; D., Macfarlane; B., Ratcliff; M., Sullivan; J., Va’Vra; W., Wisniewski; W., Yang; K., Shougaev; A., Soffer; F., Bianchi; D., Gamba; G., Giraudo; P., Mereu; G., Dalla Betta; G., Fontana; G., Soncini; M., Bomben; L., Bosisio; P., Cristaudo; G., Giacomini; D., Jugovaz; L., Lanceri; I., Rashevskaya; G., Venier; L., Vitale; R., Henderson; J. F., Caron; C., Hearty; P., Lu; R., So; P., Taras; A., Agarwal; J., Franta; J. M., Rone
SuperB: A High-Luminosity Asymmetric e+ e- Super Flavor Factory. Conceptual Design Report.
The physics objectives of SuperB, an asymmetric electron-positron collider with a luminosity above 10^36/cm^2/s are described, together with the conceptual design of a novel low emittance design that achieves this performance with wallplug power comparable to that of the current B Factories, and an upgraded detector capable of doing the physics in the SuperB environment
Measurement of the CP violating asymmetry amplitude sin 2beta
We present results on time-dependent CP-violating asymmetries in neutral B
decays to several CP eigenstates. The measurements use a data sample of about
88 million Y(4S) --> B Bbar decays collected between 1999 and 2002 with the
BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We study
events in which one neutral B meson is fully reconstructed in a final state
containing a charmonium meson and the other B meson is determined to be either
a B0 or B0bar from its decay products. The amplitude of the CP-violating
asymmetry, which in the Standard Model is proportional to sin2beta, is derived
from the decay-time distributions in such events. We measure sin2beta = 0.741
+/- 0.067 (stat) +/- 0.034 (syst) and |lambda| = 0.948 +/- 0.051 (stat) +/-
0.030 (syst). The magnitude of lambda is consistent with unity, in agreement
with the Standard Model expectation of no direct CP violation in these modes.Comment: 7 pages, 2 postscript figures, submitted to PR
F-2(D(3)) measurements at ZEUS
Results on the diffractive structure function F-2(D(3)) in deep inelastic neutral current positron-proton scattering (DIS) have been obtained by the ZEUS collaboration using two different methods. Diffractive interactions are selected by either requiring a small, not exponentially suppressed invariant hadronic mass M-X in the main detector or by detecting a fast proton in the ZEUS leading proton spectrometer (LPS). The results of the two methods are compared
Recent photoproduction results from ZEUS
Recent results for inclusive jet cross sections, dijet cross sections and dijet angular distributions are compared with NLO perturbative QCD calculations. The observation of isolated high PT photons (prompt photons) is also reported
Event shape analysis of multihadronic final states in deep inelastic rapidity gap events at HERA
A global event shape analysis of the multihadronic final states observed in deep inelastic scattering (DIS) with a large forward rapidity gap (LRG) is performed in the range Q(2) greater than or equal to 5 GeV2, 160 GeV less than or equal to W less than or equal to 250 GeV and eta(max) less than or equal to 1.8. Particular emphasis is paid to the dependence of these variables, measured in the gamma*-pomeron rest frame, upon M-X, the mass of the hadronic final state. With increasing M-X the multihadronic final states become planar. The broadening effects exhibited by the data can be described by including a gluon density in models where the pomeron has a partonic structure or alternatively by considering a direct coupling of the pomeron to quark and gluon pairs
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