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| | 3 | == Basic kinematics in hadron hadron collisions == |
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| | 5 | The rapidity %$y$% and pseudo-rapidity %$\eta$% are defined as: |
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| | 9 | where the %$z$% direction is that of the colliding beams. |
| | 10 | ==== 1. ==== |
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| | 12 | Verify that for a particle of mass %$m$% : |
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| | 16 | ==== 2. ==== |
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| | 18 | Prove that %$\tanh \eta=\cos \theta$%. |
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| | 20 | ==== 3. ==== |
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| | 22 | Consider a set of particles produced uniformly in longitudinal phase space |
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| | 26 | Find the distribution in %$\eta$%. |
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| | 28 | ==== 4. ==== |
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| | 30 | Prove that rapidity equals pseudo-rapidity, %$\eta=y$% for a relativistic particle %$E\gg m$%. |
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| | 32 | ==== 5. ==== |
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| | 34 | Prove that for Lorentz transformation (boost) in the beam (%$z$%) directions, the rapidity %$y$% of every particle is shifted by a constant %$y_0$%, related to the boost velocity. Find the relation between %$\beta$% and %$y_0$% for a generic boost: |
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| | 38 | ==== 6. ==== |
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| | 40 | Consider a generic particle %$X$% of mass %$M$% (such as a Z boson or a Higgs) produced on shell at the LHC , with zero transverse momentum, %$pp \to X$%. Find the relevant values of %$x_1,x_2$% of the initial partons that can be accessed by producing such a particle. Compare your results with that of Fig.1, considering the scale %$Q=M$%. |
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| | 42 | <img width="559" alt="lhcgridx.png" src="%ATTACHURLPATH%/lhcgridx.png" height="796" /> |
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| | 44 | Fig.1 |
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