我們執行一個全球性的分析根據樹階層開弦震幅在 s << M2S的極限。依據目前從 Tevatron, HERA, LEP2 得到的數據，對於不同的Chan-Paton factors |T| = 0－4，在95%信賴區間內我們給定string scale一個最低極限 0.69－1.9 TeV 。我們也估計預期的 sensitivity 在 LHC可能高達19 TeV對於 |T| = 4。

Abstract
We perform a global analysis of the tree-level open-string amplitudes in the limit s << MS2. Based on the present data from the Tevatron, HERA, and LEP 2, we set a lower limit on the string scale MS > 0.69–1.96 TeV at 95% confidence level for the Chan-Paton factors |T| = 0 – 4. We also estimate the expected sensitivities at the LHC, which can be as high as 19 TeV for |T| = 4.

Bibliography
[1] P. Horava and E. Witten, Nucl.Phys. B460, 506 (1996).
[2] N. Arkani-Hamed, S. Dimopoulos, G. Dvali, Phys. Lett. B429, 263
(1998); Phys. Rev. D59, 086004 (1999).
[3] J. D. Lykken, Phys. Rev. D54, 3693 (1996) [hep-th/9603133].
[4] G. Shiu and S.H. Tye, Phys. Rev. D58, 106007 (1998) [hep-ph/9805157].
[5] K. Cheung [hep-ph/0409028].
[6] S. Cullen, M. Perelstein and M.E. Peskin, Phys. Rev. D62, 055012
(2000) [hep-ph/0001166].
[7] F. Cornet, J.I. Illana and M. Masip, Phys. Rev. Lett. 86, 4235 (2001)
[hep-ph/0102065].
[8] J. Friess, T. Han and D. Hooper, Phys. Lett. B547, 31 (2002) [hepph/
0204112].
[9] P. Burikham, T. Han, F. Hussain and D. McKay, Phys. Rev. D69,
095001 (2004) [hep-ph/0309132].
[10] P. Burikham, F.Figy, and T. Han, Phys.Rev. D71, 016005 (2005) [hepph/
0411094].
[11] L. Randall and R. Sundrum, Phys. Rev. Lett. 83, 3370 (1999) [hepph/
9905221].
[12] E. Eichten, K. Lane and M.E. Peskin, Phys. Rev. Lett. 50, 811 (1983);
V. Barger, K. Cheung, K. Hagiwara, and D. Zeppenfeld, Phys. Rev.
D57, 391 (1998).
[13] K. Cheung, Phys. Lett. B517, 167 (2001).
[14] J. E. Paton and H. M. Chan, Nucl. Phys. B10, 516 (1969).
[15] G. Veneziano, Nuovo Cim. 57A, 190 (1968); Phys. Reports C9, 199
(1974).
[16] H.L. Lai et al. (CTEQ Collaboration), Eur. Phys. J. C12, 375 (2000).
[17] T. Affolder et al. (CDF Collaboration), Phys.Rev.Lett. 87, 131802
(2001) [hep-ex/0106047].
[18] B. Abbott et al. (DØ Collaboration), Phys. Rev. Lett. 82, 4769 (1999).
[19] ZEUS Collaboration, Eur.Phys.J. C32, 1 (2003) [hep-ex/0307043].
[20] ZEUS Collaboration, Phys.Rev. D70, 052001 (2004) [hep-ex/0401003].
[21] H1 Collaboration, Eur.Phys.J. C30, 1 (2003) [hep-ex/0304003].
[22] ZEUS Collaboration, Phys.Lett. B539, 197 (2002) [hep-ex/0205091].
[23] ZEUS Collaboration, Eur.Phys.J. C28, 175(2003) [hep-ex/0208040].
[24] H1 Collaboration, C. Adloff, et al. Eur.Phys.J. C19, 269 (2001) [hepex/
0012052].
[25] The LEP Collaborations: ALEPH Collaboration, DELPHI Collaboration,
L3 Collaboration, OPAL Collaboration, the LEP Electroweak
Working Group, the SLD Electroweak, Heavy Flavour Groups [hepex/
0412015].
[26] DELPHI Collaboration, http://delphiwww.cern.ch/pubxx/conferences/beijing/
(2004).
[27] OPAL Collaboration, http://opal.web.cern.ch/Opal/pubs/ichep2004/abstr.html
(2004).
[28] K. Cheung and G. Landsberg, Phys. Rev. D 62, 076003 (2000).