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1.
The partial width of the τ → e - v e v τ can be calculated from the tau mass, lifetime and branching ratio. The increasing precision on these measurements is making the partial width sensitive to the mass of the tau neutrino. We present the tau neutrino mass dependence on the partial width and show that this leads to a limit of m r < 71 MeV at the 95% confidence level. We show that the limit is determined by the uncertainty in the tau lifetime and τ → e?v e v τ branching ratio. Additional measurements of these values are expected in the next few years and we show that the limit could become competitive with the direct measurements. 相似文献
2.
R. R. Mendel Kimball A. Milton James H. Reid Mark A. Samuel 《Zeitschrift fur Physik C Particles and Fields》1986,32(4):517-520
Several methods to determine (or set an upper bound on) the mass of the tau neutrino are described. The decay spectrum of \(\tau \to e\bar \nu _e \nu _\tau \) near the high center-of-mass electron-energy end is particularly sensitive to the tau-neutrino mass. It is shown that an upper bound of 20 MeV or lower may be feasible. In addition, improved limits on the mass and mixing angle of a heavy component of the tau-neutrino may be readily obtained. We also discuss the purely leptonic decays of theD andF mesons, and show how measurements of the ratiosB(D→τντ/B(D→μνμ,B(F→τντ/B(D→μνμ can be sensitive to tau-neutrino masses of 30 MeV or greater. 相似文献
3.
R. Barate et al. 《The European Physical Journal C - Particles and Fields》1998,2(3):395-406
A bound on the tau neutrino mass is established using the data collected from 1991 to 1995 at with the ALEPH detector. Two separate limits are derived by fitting the distribution of visible energy vs invariant mass
in and decays. The two results are combined to obtain a 95% confidence level upper limit of 18.2 MeV/c on the mass of the tau neutrino.
Received: 30 October 1997 / Published online: 10 March 1998 相似文献
4.
The cascade mass reconstruction approach was used for mass reconstruction of the lightest $
\tilde \tau
$
\tilde \tau
produced at the LHC in the cascade decay $
\tilde g \to \tilde bb \to \tilde \chi _2^0 bb \to \tilde \tau _1 \tau bb \to \tilde \chi _1^0 \tau \tau bb
$
\tilde g \to \tilde bb \to \tilde \chi _2^0 bb \to \tilde \tau _1 \tau bb \to \tilde \chi _1^0 \tau \tau bb
. The $
\tilde \tau _1
$
\tilde \tau _1
mass was reconstructed assuming that masses of gluino, bottom squark, and two lightest neutralinos were reconstructed in
advance. SUSY data sample sets for the SU(3) model point containing 160k events each were generated which corresponded to an integrated luminosity of about 8 fb−1 at 14 TeV. These events were passed through the AcerDET detector simulator, which parametrized the response of a generic
LHC detector. The mass of the $
\tilde \tau _1
$
\tilde \tau _1
was reconstructed with a precision of about 20% on average. 相似文献
5.
Aubert B Bona M Boutigny D Couderc F Karyotakis Y Lees JP Poireau V Tisserand V Zghiche A Grauges E Palano A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Charles E Gill MS Groysman Y Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Pegna DL Lynch G Mir LM Orimoto TJ Pripstein M Roe NA Ronan MT Wenzel WA del Amo Sanchez P Barrett M Ford KE Harrison TJ Hart AJ Hawkes CM Watson AT Held T Koch H Lewandowski B Pelizaeus M 《Physical review letters》2008,100(1):011801
Using a data sample corresponding to an integrated luminosity of 342 fb(-1) collected with the BABAR detector at the SLAC PEP-II electron-positron storage ring operating at a center-of-mass energy near 10.58 GeV, we measure B(tau(-)--> pi(-)pi(-)pi+nu(tau)(ex.K(S0))=(8.83+/-0.01+/-0.13)%, B(tau(-) -->K(-)pi(-)pi+nu tau(ex.K(S0))=(0.273+/-0.002+/-0.009)%, B(tau(-) -->K(-)pi(-)K+nu tau)=(0.1346+/-0.0010+/-0.0036)%, and B(tau(-) -->K(-)K(-)K+nu tau)=(1.58+/-0.13+/-0.12)x10;{-5}, where the uncertainties are statistical and systematic, respectively. These include significant improvements over previous measurements and a first measurement of B(tau(-) -->K(-)K(-)K+nu tau) in which no resonance structure is assumed. We also report a first measurement of B(tau(-) -->var phi(-)nu tau)=(3.42+/-0.55+/-0.25)x10(-5), a new measurement of B(tau(-) -->var phi K(-)nu tau)=(3.39+/-0.20+/-0.28)x10(-5) and a first upper limit on B(tau(-) -->K(-)K(-)K+nu tau(ex.var phi)). 相似文献
6.
Viehhauser G Wang JC Wolf A Wu J Csorna SE McLean KW Marka S Xu Z Godang R Kinoshita K Lai IC Schrenk S Bonvicini G Cinabro D Greene R Perera LP Zhou GJ Chan S Eigen G Lipeles E Schmidtler M Shapiro A Sun WM Urheim J Weinstein AJ Wurthwein F 《Physical review letters》2000,84(5):830-834
Using 4.68 fb(-1) of e(+)e(-) annihilation data collected with the CLEO II detector at the Cornell Electron Storage Ring, we have studied tau radiative decays tau(-)-->nu(tau)&mgr;(-)nu;(&mgr;)gamma and tau(-)-->nu(tau)e(-)nu;(e)gamma. For a 10 MeV minimum photon energy in the tau rest frame, the branching fraction for radiative tau decay to a muon or electron is measured to be (3.61+/-0.16+/-0. 35)x10(-3) or (1.75+/-0.06+/-0.17)x10(-2), respectively. The branching fractions are in agreement with standard model theoretical predictions. 相似文献
7.
Anastassov A Duboscq JE Eckhart E Gan KK Gwon C Hart T Honscheid K Hufnagel D Kagan H Kass R Pedlar TK Schwarthoff H Thayer JB von Toerne E Zoeller MM Richichi SJ Severini H Skubic P Undrus A Chen S Fast J Hinson JW Lee J Miller DH Shibata EI Shipsey IP Pavlunin V Cronin-Hennessy D Lyon AL Thorndike EH Jessop CP Savinov V Coan TE Fadeyev V Maravin Y Narsky I Stroynowski R Ye J Wlodek T Artuso M Ayad R Boulahouache C Bukin K Dambasuren E Karamov S Majumder G Moneti GC Mountain R Schuh S 《Physical review letters》2001,86(20):4467-4471
The tau decays to six-pion final states have been studied with the CLEO detector at the Cornell Electron Storage Ring. The measured branching fractions are B(tau(-)-->2pi(-)pi(+)3pi(0)nu(tau)) = (2.2+/-0.3+/-0.4)x10(-4) and B(tau(-)-->3pi(-)2pi(+)pi(0)nu(tau)) = (1.7+/-0.2+/-0.2)x10(-4). A search for substructure in these decays shows that they are saturated by intermediate states with eta or omega mesons. We present the first observation of the decay tau(-)-->2pi(-)pi(+)omega(nu)tau and the branching fraction is measured to be (1.2+/-0.2+/-0.1)x10(-4). The measured branching fractions are in good agreement with the isospin expectations but somewhat below the conserved-vector-current predictions. 相似文献
8.
Ecklund KM Love W Savinov V Lopez A Mendez H Ramirez J Ge JY Miller DH Shipsey IP Xin B Adams GS Anderson M Cummings JP Danko I Hu D Moziak B Napolitano J He Q Insler J Muramatsu H Park CS Thorndike EH Yang F Artuso M Blusk S Khalil S Li J Mountain R Nisar S Randrianarivony K Sultana N Skwarnicki T Stone S Wang JC Zhang LM Bonvicini G Cinabro D Dubrovin M Lincoln A Rademacker J Asner DM Edwards KW Naik P Reed J Briere RA Ferguson T Tatishvili G Vogel H Watkins ME Rosner JL Alexander JP 《Physical review letters》2008,100(16):161801
Using a sample of tagged D(s)(+) decays collected near the D(s)(*+/-)D(s)(-/+) peak production energy in e(+)e(-) collisions with the CLEO-c detector, we study the leptonic decay D(s)(+)-->tau(+)nu(tau) via the decay channel tau(+)-->e(+)nu(e)nu(tau). We measure B(D(s)(+)-->tau(+)nu(tau))=(6.17+/-0.71+/-0.34)%, where the first error is statistical and the second systematic. Combining this result with our measurements of D(s)(+)-->mu(+)nu(mu) and D(s)(+)-->tau(+)nu(tau) (via tau(+)-->pi(+)nu(tau)), we determine f(D(s))=(274+/-10+/-5) MeV. 相似文献
9.
Bornheim A Lipeles E Pappas SP Weinstein AJ Briere RA Chen GP Ferguson T Tatishvili G Vogel H Watkins ME Adam NE Alexander JP Berkelman K Cassel DG Duboscq JE Ecklund KM Ehrlich R Fields L Galik RS Gibbons L Gittelman B Gray R Gray SW Hartill DL Heltsley BK Hertz D Hsu L Jones CD Kandaswamy J Kreinick DL Kuznetsov VE Mahlke-Krüger H Meyer TO Onyisi PU Patterson JR Peterson D Pivarski J Riley D Rosner JL Ryd A Sadoff AJ Schwarthoff H Shepherd MR Sun WM Thayer JG Urner D Wilksen T Weinberger M 《Physical review letters》2004,93(24):241802
We have searched a sample of 9.6 x 10(6) BB events for the lepton-flavor-violating leptonic B decays, B(0)-->mu(+/-)tau(-/+) and B(0)-->e(+/-)tau(-/+). The tau lepton was detected through the decay modes tau-->lnunu(-) , where l=e, mu. There is no indication of a signal, and we obtain the 90% confidence level upper limits B(B(0)-->mu(+/-)tau(-/+))<3.8 x 10(-5) and B(B(0)-->e(+/-)tau(-/+))<1.3 x 10(-4). 相似文献
10.
Briere RA Chen GP Ferguson T Tatishvili G Vogel H Adam NE Alexander JP Berkelman K Boisvert V Cassel DG Drell PS Duboscq JE Ecklund KM Ehrlich R Galik RS Gibbons L Gittelman B Gray SW Hartill DL Heltsley BK Hsu L Jones CD Kandaswamy J Kreinick DL Magerkurth A Mahlke-Krüger H Meyer TO Mistry NB Patterson JR Peterson D Pivarski J Richichi SJ Riley D Sadoff AJ Schwarthoff H Shepherd MR Thayer JG Urner D Wilksen T Warburton A Weinberger M Athar SB Avery P Breva-Newell L Potlia V Stoeck H Yelton J 《Physical review letters》2003,90(18):181802
From electron-positron collision data collected with the CLEO detector operating at Cornell Electron Storage Ring near sqrt[s]=10.6 GeV, improved measurements of the branching fractions for tau decays into three explicitly identified hadrons and a neutrino are presented as B(tau(-)-->pi(-)pi(+)pi(-)nu(tau))=(9.13+/-0.05+/-0.46)%, B(tau(-)-->K-pi(+)pi(-)nu(tau))=(3.84+/-0.14+/-0.38) x 10(-3), B(tau(-)-->K-K+pi(-)nu(tau))=(1.55+/-0.06+/-0.09) x 10(-3), and B(tau(-)-->K-K+K-nu(tau))<3.7 x 10(-5) at 90% C.L., where the uncertainties are statistical and systematic, respectively. 相似文献
11.
Matyja A Rozanska M Adachi I Aihara H Aulchenko V Aushev T Bahinipati S Bakich AM Balagura V Barberio E Bedny I Bhardwaj V Bitenc U Bondar A Bozek A Bracko M Brodzicka J Browder TE Chang MC Chang P Chen A Chen KF Cheon BG Chistov R Cho IS Choi Y Choi YK Dalseno J Dash M Eidelman S Fratina S Gabyshev N Golob B Ha H Haba J Hara T Hayasaka K Hazumi M Heffernan D Hokuue T Hoshi Y Hou WS Hyun HJ Iijima T Ikado K Inami K Ishikawa A Ishino H Itoh R Iwasaki Y Kaji H Kajiwara S Kang JH Katayama N 《Physical review letters》2007,99(19):191807
We report an observation of the decay B{0}-->D{*-}tau{+}nu{tau} in a data sample containing 535x10{6} BB pairs collected with the Belle detector at the KEKB asymmetric-energy e{+}e{-} collider. We find a signal with a significance of 5.2sigma and measure the branching fraction B(B{0}-->D{*-}tau{+}nu{tau})=(2.02{-0.37}{+0.40}(stat)+/-0.37(syst))%. This is the first observation of an exclusive B decay with a b-->ctaunu{tau} transition. 相似文献
12.
Abe K Hayato Y Iida T Ishihara K Kameda J Koshio Y Minamino A Mitsuda C Miura M Moriyama S Nakahata M Obayashi Y Ogawa H Shiozawa M Suzuki Y Takeda A Takeuchi Y Ueshima K Higuchi I Ishihara C Ishitsuka M Kajita T Kaneyuki K Mitsuka G Nakayama S Nishino H Okumura K Saji C Takenaga Y Totsuka Y Clark S Desai S Dufour F Kearns E Likhoded S Litos M Raaf JL Stone JL Sulak LR Wang W Goldhaber M Casper D Cravens JP Kropp WR Liu DW Mine S Regis C Smy MB Sobel HW Vagins MR Ganezer KS Hill JE Keig WE 《Physical review letters》2006,97(17):171801
A search for the appearance of tau neutrinos from nu(mu) <--> nu(tau) oscillations in the atmospheric neutrinos has been performed using 1489.2 days of atmospheric neutrino data from the Super-Kamiokande-I experiment. A best fit tau neutrino appearance signal of 138+/-48(stat)-32(+15)(syst) events is obtained with an expectation of 78+/-26(syst). The hypothesis of no tau neutrino appearance is disfavored by 2.4 sigma. 相似文献
13.
Abraham J Abreu P Aglietta M Aguirre C Allard D Allekotte I Allen J Allison P Alvarez-Muñiz J Ambrosio M Anchordoqui L Andringa S Anzalone A Aramo C Argirò S Arisaka K Armengaud E Arneodo F Arqueros F Asch T Asorey H Assis P Atulugama BS Aublin J Ave M Avila G Bäcker T Badagnani D Barbosa AF Barnhill D Barroso SL Bauleo P Beatty JJ Beau T Becker BR Becker KH Bellido JA BenZvi S Berat C Bergmann T Bernardini P Bertou X Biermann PL Billoir P Blanch-Bigas O Blanco F Blasi P Bleve C Blümer H 《Physical review letters》2008,100(21):211101
The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV. 相似文献
14.
《Physics letters. [Part B]》1999,459(4):607-614
The hadronic tau decay channel offers by far the best signature for heavy charged Higgs boson search at the LHC in the large tanβ region. By exploiting the distinct polarization of the tau and its large transverse mass, along with the accompanying missing–pT, one can probe for a charged Higgs boson up to a mass of about 600 GeV in an essentially background-free environment. The transverse mass distribution of the tau jet also provides a fairly unambiguous estimate of the charged Higgs boson mass. 相似文献
15.
Aubert B Barate R Boutigny D Couderc F Karyotakis Y Lees JP Poireau V Tisserand V Zghiche A Grauges-Pous E Palano A Pompili A Chen JC Qi ND Rong G Wang P Zhu YS Eigen G Ofte I Stugu B Abrams GS Borgland AW Breon AB Brown DN Button-Shafer J Cahn RN Charles E Day CT Gill MS Gritsan AV Groysman Y Jacobsen RG Kadel RW Kadyk J Kerth LT Kolomensky YG Kukartsev G Lynch G Mir LM Oddone PJ Orimoto TJ Pripstein M Roe NA Ronan MT Wenzel WA Barrett M Ford KE Harrison TJ Hart AJ Hawkes CM Morgan SE 《Physical review letters》2005,95(4):041802
A search for the nonconservation of lepton flavor number in the decay tau(+/-) --> mu(+/-) has been performed using 2.07 x 10(8) e(+ )e(-) tau(+) tau(-) events produced at a center-of-mass energy near 10.58 GeV with the BABAR detector at the PEP-II storage ring. We find no evidence for a signal and set an upper limit on the branching ratio of Beta(tau(+/-) --> mu(+/-) gamma) < 6.8 x 10(-8) at 90% confidence level. 相似文献
16.
Acosta D Adelman J Affolder T Akimoto T Albrow MG Ambrose D Amerio S Amidei D Anastassov A Anikeev K Annovi A Antos J Aoki M Apollinari G Arisawa T Arguin JF Artikov A Ashmanskas W Attal A Azfar F Azzi-Bacchetta P Bacchetta N Bachacou H Badgett W Barbaro-Galtieri A Barker GJ Barnes VE Barnett BA Baroiant S Bauer G Bedeschi F Behari S Belforte S Bellettini G Bellinger J Belloni A Ben-Haim E Benjamin D Beretvas A Berry T Bhatti A Binkley M Bisello D Bishai M Blair RE Blocker C Bloom K 《Physical review letters》2005,95(13):131801
We present the results of a search for anomalous resonant production of tau lepton pairs with large invariant mass, the first such search using the CDF II Detector in Run II of the Tevatron pp collider. Such anomalous production could arise from various new physics processes. In a data sample corresponding to 195 pb(-1) of integrated luminosity we predict 2.8+/-0.5 events from standard model background processes and observe 4. We use this result to set limits on the production of heavy scalar and vector particles decaying to tau lepton pairs. 相似文献
17.
Recent experimental results on hadronic tau decays into strange particles by the OPAL Collaboration are employed to determine V(us) and m(s) from moments of the invariant mass distribution. Our results are V(us)=0.2208+/-0.0034 and m(s)(2 GeV)=81+/-22 MeV. The error on V(us) is dominated by experiment and should be improvable in the future. Nevertheless, already now our result is competitive with the standard extraction of V(us) from K(e3) decays, and it is compatible with unitarity. 相似文献
18.
Early black hole formation in a core-collapse supernova will abruptly truncate the neutrino fluxes. The sharp cutoff can be used to make model-independent time-of-flight neutrino mass tests. Assuming a neutrino luminosity of 10(52) erg/s per flavor at cutoff and a distance of 10 kpc, Super-Kamiokande can detect an electron neutrino mass as small as 1.8 eV, and the proposed OMNIS detector can detect mu and tau neutrino masses as small as 6 eV. We present the first technique with direct sensitivity to eV-scale mu and tau neutrino masses. 相似文献
19.
J.G. Körner F. Krajewski A.A. Pivovarov 《The European Physical Journal C - Particles and Fields》2001,20(2):259-269
We present an analysis of the -corrections to Cabibbo-suppressed -lepton decays employing contour improved resummation within an effective scheme which is an essential new feature as compared
to previous analyses. The whole perturbative QCD dynamics of the -system is described by the -function of the effective coupling constant and by two -functions for the effective mass parameters of the strange quark in different spin channels. We analyze the stability of
our results with regard to high-order terms in the perturbative expansion of the renormalization group functions. A numerical
value for the strange quark mass in the scheme is extracted: $m_s(M_\tau)=130\pm 27_{\mathrm{{exp}}}\pm 9_{\mathrm{{th}}}{\mathrm{ MeV}}$. After running to the scale
this translates into .
Received: 1 October 2000 / Revised version: 22 February 2001 / Published online: 18 May 2001 相似文献
20.
Aubert B Bona M Karyotakis Y Lees JP Poireau V Prudent X Tisserand V Zghiche A Garra Tico J Grauges E Lopez L Palano A Pappagallo M Eigen G Stugu B Sun L Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lopes Pegna D Lynch G Orimoto TJ Osipenkov IL Ronan MT Tackmann K Tanabe T Wenzel WA Del Amo Sanchez P Hawkes CM Soni N Watson AT Koch H Schroeder T Walker D Asgeirsson DJ Cuhadar-Donszelmann T Fulsom BG Hearty C Mattison TS 《Physical review letters》2008,100(7):071802
A search for lepton flavor violating decays of a tau to a lighter-mass charged lepton and an omega vector meson is performed using 384.1 fb(-1) of e(+)e(-) annihilation data collected with the BABAR detector at the Stanford Linear Accelerator Center PEP-II storage ring. No signal is found, and the upper limits on the branching ratios are determined to be B(tau(+/-)-->e;{+/-}omega)<1.1 x10 (-7) and B(tau(+/-)-->micro(+/-)omega)<1.0 x 10(-7) at 90% confidence level. 相似文献