What is Section: Definition and 733 Discussions

If given the cross section for ZZ* to two leptons, is it possible to work out the cross section for ZZ* to just electrons or muons from it? So excluding the tau decay mode, unless ##ZZ^{*} \rightarrow \tau + \tau## can't happen anyway? I'm guessing it wouldn't just be two thirds of the ##ZZ...

I am reading An Introduction to Rings and Modules With K-Theory in View by A.J. Berrick and M.E. Keating (B&K). In Chapter2: Direct Sums and Short Exact Sequences in Section 2.1.16 B&K deal with the standard free right ##R##-module on a set ##X##. I need some help with understanding an aspect...

Homework Statement Find force in members EA, EF and EG given the loads shown. A and G are pinned supports. Homework Equations Three equations of equilibrium for sections (method of sections) 2 equations for any node (method of joints). I also used the dimensions to decompose member forces. The...

I am reading Louis Rowen's book, "Ring Theory"(Student Edition) ... I have a problem interpreting Rowen's notation in Section 1.1 Matrix Rings and Idempotents ... The relevant section of Rowen's text reads as follows: In the above text from Rowen, we read the following: " ... ... We obtain a...

I am reading the book, Basic Abstract Algebra by P.B. Bhattacharya, S.K. Jain, and S.R. Nagpaul ... ... and am currently focused on Chapter 2: Integers, Real Numbers and Complex Numbers ... I need help with an aspect of the proof of the Fundamental Theorem of Arithmetic in Section 1.3 ... ...

Hi everyone! Please help, I have spent some considerable time to understand the two concepts and still this is nagging at me... I am relating to Structural Engineering, just to let you know guys. My question is .. Moment of inertia is about distribution of mass, the further away from the axis...

Hi everyone! Please help, I have spent a considerable time to understand the two concepts and still this is nagging at me... I am relating to Structural Engineering, just to let you know guys. My question is .. Moment of inertia is about distribution of mass, the further away from the axis the...

If the unbraced length of a beam is 3 m and the maximum bending moment in this unbraced segment is 312 kN-m, and also the maximum moment in the braced segment of the beam is 350 kN-m, select an economical section just based on the moment requirements. Use Table A.2M included in the course...

I am reading Dummit and Foote's book: Abstract Algebra ... ... and am currently focused on Section 7.4 Properties of Ideals ... ... I have a basic question regarding the generation of a two sided principal ideal in the noncommutative case ... In Section 7.4 on pages 251-252 Dummit and...

Homework Statement [/B] (Note: this is not strictly homework, but it is related to one course I'm doing, and I can't find a useful solution anywhere) Find the analytical expression for the scattering cross section of two longitudinally polarized electrons at tree level. Homework Equations...

Is there any measure for cross section of η′→γγ? Or has anyone did the calculation??

Homework Statement I have a problem in calculating cross-section in elektron-positron -> muon-antimuon scattering. Homework Equations In the relativistic limit, we find the differential cross-section of {e}+{e^-} -> {μ}+{μ^-} is \frac{d\sigma}{d\Omega}=\frac{\alpha^2}{4s}*(1+cos^2{\theta})...

I am reading the undergraduate introduction to algebraic geometry entitled "Ideals, Varieties and Algorithms: An introduction to Computational Algebraic Geometry and Commutative Algebra (Third Edition) by David Cox, John Little and Donal O'Shea ... ... I am currently focused...

Homework Statement I am reading the undergraduate introduction to algebraic geometry entitled "Ideals, Varieties and Algorithms: An introduction to Computational Algebraic Geometry and Commutative Algebra (Third Edition) by David Cox, John Little and Donal O'Shea ... ... I am currently...

Projective Algebraic Geometry - the Projective Plane ... Cox et al - Section 8.1, Exs 5(a) & 5(b) I am reading the undergraduate introduction to algebraic geometry entitled "Ideals, Varieties and Algorithms: An introduction to Computational Algebraic Geometry and Commutative Algebra...

Homework Statement I am reading the undergraduate introduction to algebraic geometry entitled "Ideals, Varieties and Algorithms: An introduction to Computational Algebraic Geometry and Commutative Algebra (Third Edition) by David Cox, John Little and Donal O'Shea ... ... I am currently...

I am reading the undergraduate introduction to algebraic geometry entitled "Ideals, Varieties and Algorithms: An introduction to Computational Algebraic Geometry and Commutative Algebra (Third Edition) by David Cox, John Little and Donal O'Shea ... ... I am currently focused on...

I am reading the undergraduate introduction to algebraic geometry entitled "Ideals, Varieties and Algorithms: An introduction to Computational Algebraic Geometry and Commutative Algebra (Third Edition) by David Cox, John Little and Donal O'Shea ... ... I am currently focused on...

I am reading the undergraduate introduction to algebraic geometry entitled "Ideals, Varieties and Algorithms: An introduction to Computational Algebraic Geometry and Commutative Algebra (Third Edition) by David Cox, John Little and Donal O'Shea ... ... I am currently focused on Chapter...

Hi all, Do any has an idea how to give a rough estimation for this process's cross section: g g -> H -> h h, (h -> b b~), ( h -> b b~) ? where h is SM Higgs and H is a heavy Higgs boson with BR (H > hh) ~ Gamma (H > hh) ~ 10^-3 GeV and sigma (g g > H ) ~ 10 pb .. When I calculated it by...

Hi all, Do anyone familiar with these analysis of cross section ? I wonder how to find the cross section of ( p p ## \to \gamma \gamma## b b~) (blue region) in the opposite plot, the y-axis is the number of events divided by 100 GeV with luminosity = 100 ##\mbox{fb}^{−1 }##.. The Fig. from...

Homework Statement I've a problem with defining x function for the lower horizontal bar on the left hand side. Is it shear flow for this part = Vx/Iy * 3 * s^2 * 0.5 (after integration) ? Or should I take whole x part on which is acting force Vx? Homework EquationsThe Attempt at a Solution

Hey, working on something for a personal project and was wondering if you could point me in the right direction. I have a 47 inch hollow steel tube that I'm going to cut the end 6 inches into a half circle tube . I have a load of 200 lb at the top and am wondering how about I would quickly...

I am reading the undergraduate introduction to algebraic geometry entitled "Ideals, Varieties and Algorithms: An introduction to Computational Algebraic Geometry and Commutative Algebra (Third Edition) by David Cox, John Little and Donal O'Shea ... ... I am currently focused on Chapter 1...

Homework Statement The train is traveling in a gallery at ##v=70 km/h##. Outside air is not moving and pressure is ##p_0=101325 Pa## and temperature ##T=283 K ##. The area of the face of the train is ##A=9 m^2##. Determine the minimum area of the section of the gallery such that the pressure...

I am not sure what does Jackson want to talk in section 9-6? Is that just a review of something discussed previously? Chapter 9 is talking about radiation, and later about multipole expansion.

Given an equation, we can determine which type of conic section it describes by calculating ##d=B^2-4AC## (see attachment). However, the theorem demands that the equation describes a conic section. So how do we show that it does? Does there exist a counterexample where ##B^2-4AC<0##, but it is...

I want to know how mathematician got the idea of external division , how they can say that a point can divide a line externally, what's the reason behind this discovery . Why they discovered it.

I am reading Dummit and Foote: Abstract Algebra (Third Edition) ... and am focused on Section 11.5 Tensor Algebras. Symmetric and Exterior Algebras ... In particular I am trying to understand Theorem 31 but at present I am very unsure about how to interpret the theorem and need some help in...

I am reading Dummit and Foote: Abstract Algebra (Third Edition) ... and am focused on Section 11.5 Tensor Algebras. Symmetric and Exterior Algebras ... In particular I am trying to understand Theorem 31 but at present I am very unsure about how to interpret the theorem and need some help in...

I am reading Dummit and Foote's book: Abstract Algebra ... ... and am currently focused on Section 10.4 Tensor Products of Modules ... ... I have a basic question regarding the extension of the scalars ... Dummit and Foote's exposition regarding extension of the scalars reads as...

I am reading Dummit and Foote's book: Abstract Algebra ... ... and am currently focused on Section 10.4 Tensor Products of Modules ... ... I have a basic question regarding the extension of the scalars ... Dummit and Foote's (D&Fs) exposition regarding extension of the scalars reads as...

I am reading Dummit and Foote's book: Abstract Algebra ... ... and am currently focused on Section 6.3 A Word on Free Groups ... I have a basic question regarding the nature and character of free groups ... Dummit and Foote's introduction to free groups reads as follows: In the above text...

I am reading Dummit and Foote's book: Abstract Algebra ... ... and am currently focused on Section 6.3 A Word on Free Groups ... I have a basic question regarding the nature and character of free groups ... Dummit and Foote's introduction to free groups reads as...

In the research,it is found there is significant difference of B-10(n,2a)H-3 reaction cross section between ENDF/B-V and ENDF/B-VI (http://www.nndc.bnl.gov/).The cross section in ENDF/B-V is 10 times less than ENDF/B-VI when neutron energy...

I am reading Anthony W. Knapp's book: Basic Algebra in order to understand tensor products ... ... I need some help with an aspect of Theorem 6.10 in Section 6 of Chapter VI: Multilinear Algebra ... The text of Theorem 6.10 reads as follows: The above proof mentions Figure 6.1 which is...

I am reading Anthony W. Knapp's book: Basic Algebra in order to understand tensor products ... ... I need some help with an aspect of Theorem 6.10 in Section 6 of Chapter VI: Multilinear Algebra ... The text of Theorem 6.10 reads as follows: About midway in the above text, just at the start...

I am reading Anthony W. Knapp's book: Basic Algebra in order to understand tensor products ... ... I need some help with an aspect of Theorem 6.10 in Section 6 of Chapter VI: Multilinear Algebra ... The text of Theorem 6.10 reads as follows:https://www.physicsforums.com/attachments/5391...

I need to mount several rectangular orifices or sections on a wall with those two factors: - 20 Pascals differential pressure (negative pressure inside) - Inlet air speed 1100 feet per minute (5.58 meters per minute) I've got the section of each window, and the air caudal to renovate. I would...

I am reading Segei Winitzki's book: Linear Algebra via Exterior Products ... I am currently focused on Section 1.6: Dual (conjugate) vector space ... ... I need help in order to get a clear understanding of an aspect of the notion or concept of the dual basis \{ e^*_1, e^*_2, \ ... \ ... \...

Hi! On page 12 of http://pdg.lbl.gov/2009/reviews/rpp2009-rev-cross-section-plots.pdf one can see the total cross section increasing beyond a certain treshold. At higher energy protons (and their quarks) have a shorter wave length and so they can become closer an closer and the strong force...

I am reading Susan Colley's book: Vector Calculus ... and am currently focussed on Section 8.1: An Introduction to Differential Forms ... ... Colley, on page 491 in Example 3 gives a formula for a general 2-form as follows:I am trying to understand what Colley describes as 'the somewhat curious...

Hi all, I try to find the exact calculated gluon- gluon fusion cross section for the SM- Higgs with mass 125 GeV, for instance at CME = 14 TeV. I found on twiki page: " https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CERNYellowReportPageAt1314TeV#s_14_0_TeV " ##\sigma(gg \to h) = 49.47~ pb##...

In chapter 1 of Peskin and Schroeder, the reaction ##e^{+}e^{-}\rightarrow \mu^{+}\mu^{-}## is studied in detail. The related following paragraph is taken from page 4 of Peskin and Schroeder: Both the electron and the muon have spin ##1/2##, so their spin orientations must be specified. It is...

Hello It seems to me that the nuclei have a flat elastic scattering cross section of neutrons, for neutron energies from eV to MeV. http://www.nuclear-power.net/wp-content/uploads/2015/11/Elastic-Scattering-Cross-section-light-elements-min.png I thought that maybe it was caused because the...

I am reading Bruce Cooperstein's book: Advanced Linear Algebra ... ... I am focused on Section 1.3 Vector Spaces over an Arbitrary Field ... I need help with Exercise 1 of Section 1.3 ... Exercise 1 reads as follows:Although apparently simple, I cannot solve this one and would appreciate...

The question is as follows: Prove that any timelike vector for which ##U^0>0## and ##\vec{U}\cdot \vec{U} = -1## is the 4-velocity of some world line. I need to show that there exists a 4-vector ##\vec{x}##, s.t ##\frac{d\vec{x}}{d\tau} = \vec{U}##, where ##\vec{x}## is a world line of some...

I'm trying to figure our the relation between cross section, scattering angle and KE? I'm doing a few exercises where I've been given kientic energy and scattering angle and have to calculate the cross section. Cross section is in units of Barns (m2), and KE is 1/2 kg*m2*s-2, but I can't seem...

I am reading the book Mathematical Logic by Ian Chiswell and Wilfred Hodges ... and am currently focused on Chapter 3: Propositional Logic and, in particular, Section 3.4: Propositional Natural Deduction ... I need help with understanding an aspect of Example 3.4.3 which reads as...

I am reading P.M. Cohn's book: Introduction to Ring Theory (Springer Undergraduate Mathematics Series) ... ... I am currently focused on Section 2.2: Chain Conditions ... which deals with Artinian and Noetherian rings and modules ... ... I need help to get started on Exercise 3, Section 2.2...